"""工单管理 API — 支持多数据库的变更工单生命周期管理。

核心功能:
- 工单创建、审核、执行、取消、回滚
- 多级审批流支持
- 工单状态机管理（严格的状态转换）
- 自动 SQL 审核（创建时触发）
- 执行前二次确认
- 执行后通知触发
- 完整操作审计
"""

from datetime import datetime, timezone
from enum import Enum
from typing import TYPE_CHECKING, Any, Dict, List, Optional

from fastapi import APIRouter, Depends, HTTPException, Query, Request, status
from pydantic import BaseModel, Field, field_validator
from sqlalchemy import select, func, or_
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_db
from app.core.security import get_current_user, require_role
from app.models.user import User
from app.models.ticket import Ticket
from app.models.instance import Instance
from app.models.workflow import WorkflowDefinition, WorkflowStep, TicketApproval
from app.models.audit_log import AuditLog
from app.schemas.ticket import TicketCreate, TicketReview, TicketResponse
from app.core.crypto import decrypt_password
from app.core.permissions import check_instance_access, check_instance_permission
from app.services.audit_engine import SQLAuditEngine
from app.services.audit_engine_v2 import SQLAuditEngineV2
from app.services.audit_log_service import AuditLogService
from app.services.query_service import MAX_QUERY_LENGTH
import json
import logging

logger = logging.getLogger(__name__)


def _generate_ticket_no(ticket_id: int) -> str:
    """生成工单编号，格式: YYYYMMDDHHmmss + 微秒前3位 + 序号补齐。
    
    示例: 20260522160543841
    
    Args:
        ticket_id: 工单自增ID，用作末尾序号
    
    Returns:
        工单编号字符串
    """
    now = datetime.now()
    base = now.strftime("%Y%m%d%H%M%S")
    ms = f"{now.microsecond:06d}"[:3]  # 取前3位毫秒
    seq = str(ticket_id).zfill(3)[-3:]  # ID 补齐到3位
    return f"{base}{ms}{seq}"


def _classify_sql_type(sql: str) -> str:
    """根据单条 SQL 语句判断类型。"""
    s = sql.strip().upper()
    if s.startswith(("SELECT", "SHOW", "EXPLAIN", "DESC", "DESCRIBE")):
        return "DQL"
    if s.startswith(("INSERT", "UPDATE", "DELETE", "REPLACE")):
        return "DML"
    if s.startswith(("CREATE", "ALTER", "DROP", "RENAME", "TRUNCATE")):
        return "DDL"
    if s.startswith(("GRANT", "REVOKE")):
        return "DCL"
    if s.startswith(("SET", "GET", "HSET", "HMSET", "LPUSH", "RPUSH", "SADD", "ZADD", "DEL", "FLUSHDB", "FLUSHALL")):
        return "SET"
    return "OTHER"


async def _update_sql_items_from_report(db, ticket_id: int, report) -> None:
    """根据执行报告更新 SQL items 状态。"""
    from app.models.ticket_sql_item import TicketSqlItem

    result = await db.execute(
        select(TicketSqlItem)
        .where(TicketSqlItem.ticket_id == ticket_id)
        .order_by(TicketSqlItem.seq)
    )
    items = result.scalars().all()
    if not items:
        return

    if report.status == "success":
        for item in items:
            item.status = "success"
            item.finished_at = datetime.now(timezone.utc)
    else:
        # 尝试从 raw_output 解析逐条结果
        exec_errors = getattr(report, "errors", [])
        error_stmt = ""
        if exec_errors:
            err_msg = str(exec_errors[0]) if exec_errors else ""
            # 找到出错的语句
            for item in items:
                if item.status == "pending":
                    if not error_stmt:
                        item.status = "failed"
                        item.error_message = err_msg
                        item.finished_at = datetime.now(timezone.utc)
                        error_stmt = item.sql_text[:50]
                    else:
                        item.status = "skipped"

    await db.flush()


async def _mark_sql_items_failed(db, ticket_id: int, error_msg: str) -> None:
    """标记所有 pending 的 SQL items 为 failed。"""
    from app.models.ticket_sql_item import TicketSqlItem

    result = await db.execute(
        select(TicketSqlItem)
        .where(
            TicketSqlItem.ticket_id == ticket_id,
            TicketSqlItem.status == "pending",
        )
    )
    items = result.scalars().all()
    for item in items:
        item.status = "failed"
        item.error_message = error_msg[:500]
        item.finished_at = datetime.now(timezone.utc)
    await db.flush()


async def _check_maintenance_window(db) -> Optional[str]:
    """检查当前是否在维护窗口内。

    Returns:
        None = 允许执行（无窗口限制或在窗口内）
        str = 窗口描述（表示不在窗口内，不允许执行）
    """
    from app.models.system_setting import SystemSetting
    result = await db.execute(
        select(SystemSetting).where(SystemSetting.key == "maintenance_window")
    )
    setting = result.scalar_one_or_none()
    if not setting or not setting.value:
        return None  # 无配置，不限制

    import json as _json
    try:
        window = _json.loads(setting.value) if isinstance(setting.value, str) else setting.value
    except Exception:
        return None

    enabled = window.get("enabled", False)
    if not enabled:
        return None

    # 格式: {"enabled": true, "start": "22:00", "end": "06:00", "days": ["mon","tue","wed","thu","fri"]}
    start_time = window.get("start", "22:00")
    end_time = window.get("end", "06:00")
    days = window.get("days", [])  # 空=每天

    now = datetime.now()
    current_day = now.strftime("%a").lower()[:3]
    current_time = now.strftime("%H:%M")

    # 检查星期
    if days and current_day not in [d.lower()[:3] for d in days]:
        return f"{start_time}-{end_time} ({'/'.join(days)})"

    # 检查时间（支持跨午夜）
    if start_time <= end_time:
        if not (start_time <= current_time <= end_time):
            return f"{start_time}-{end_time}"
    else:
        # 跨午夜: 22:00-06:00 意味着 22:00~24:00 或 00:00~06:00
        if not (current_time >= start_time or current_time <= end_time):
            return f"{start_time}-{end_time}（次日）"

    return None  # 在窗口内，允许执行


if TYPE_CHECKING:
    from app.services.ticket_executor import ExecutionReport

router = APIRouter(prefix="/tickets", tags=["工单管理"])


# ===== 工单状态机 =====

class TicketStatus(str, Enum):
    """工单状态枚举。"""
    PENDING = "pending"       # 待审批
    REVIEWING = "reviewing"   # 审批中（多级审批）
    APPROVED = "approved"     # 已通过
    SCHEDULED = "scheduled"   # 定时执行中
    REJECTED = "rejected"     # 已拒绝
    EXECUTING = "executing"   # 执行中
    SUCCESS = "success"       # 执行成功
    FAILED = "failed"         # 执行失败
    ROLLBACK = "rollback"     # 已回滚


# 状态转换图: 当前状态 -> 允许的目标状态
TICKET_STATE_TRANSITIONS: Dict[str, List[str]] = {
    TicketStatus.PENDING.value: [TicketStatus.REVIEWING.value, TicketStatus.APPROVED.value, TicketStatus.REJECTED.value],
    TicketStatus.REVIEWING.value: [TicketStatus.REVIEWING.value, TicketStatus.APPROVED.value, TicketStatus.REJECTED.value],
    TicketStatus.APPROVED.value: [TicketStatus.EXECUTING.value, TicketStatus.SCHEDULED.value, TicketStatus.REJECTED.value],
    TicketStatus.SCHEDULED.value: [TicketStatus.EXECUTING.value, TicketStatus.APPROVED.value],
    TicketStatus.EXECUTING.value: [TicketStatus.SUCCESS.value, TicketStatus.FAILED.value],
    TicketStatus.SUCCESS.value: [TicketStatus.ROLLBACK.value],
    TicketStatus.FAILED.value: [TicketStatus.ROLLBACK.value, TicketStatus.APPROVED.value],
    TicketStatus.REJECTED.value: [],  # 终态，不可再转换
    TicketStatus.ROLLBACK.value: [],  # 终态，不可再转换
}


def _validate_status_transition(current_status: str, new_status: str) -> bool:
    """验证工单状态转换是否合法。

    Args:
        current_status: 当前状态
        new_status: 目标状态

    Returns:
        转换是否合法
    """
    allowed = TICKET_STATE_TRANSITIONS.get(current_status, [])
    return new_status in allowed


# ===== 请求模型 =====


class AuditRequest(BaseModel):
    """SQL 审核请求。"""
    sql_content: str = Field(..., min_length=1, max_length=MAX_QUERY_LENGTH)
    instance_id: int
    database: str = ""

    @field_validator('sql_content')
    @classmethod
    def validate_sql_length(cls, v):
        if len(v) > MAX_QUERY_LENGTH:
            raise ValueError(f"SQL 内容不能超过 {MAX_QUERY_LENGTH} 字符")
        return v


class TicketExecuteConfirm(BaseModel):
    """工单执行二次确认请求。"""
    confirmed: bool = Field(..., description="是否确认执行")
    comment: str = Field(default="", max_length=500, description="执行备注")


# ===== 辅助函数 =====


async def _enrich_ticket(ticket: Ticket, db: AsyncSession) -> Dict[str, Any]:
    """丰富工单数据，添加申请人/审批人/实例名称/当前审核人等信息。"""
    data = {
        "id": ticket.id,
        "ticket_no": ticket.ticket_no,
        "title": ticket.title,
        "db_type": ticket.db_type,
        "instance_id": ticket.instance_id,
        "target_database": ticket.target_database,
        "sql_content": ticket.sql_content,
        "rollback_sql": ticket.rollback_sql,
        "status": ticket.status,
        "priority": ticket.priority,
        "risk_level": getattr(ticket, "risk_level", "low"),
        "workflow_id": getattr(ticket, "workflow_id", None),
        "applicant_id": ticket.applicant_id,
        "approver_id": ticket.approver_id,
        "reason": ticket.reason,
        "audit_result": ticket.audit_result,
        "execute_result": ticket.execute_result,
        "create_time": ticket.create_time,
        "review_time": ticket.review_time,
        "execute_time": ticket.execute_time,
    }

    # Resolve applicant name
    if ticket.applicant_id:
        r = await db.execute(select(User).where(User.id == ticket.applicant_id))
        applicant = r.scalar_one_or_none()
        data["applicant_name"] = applicant.display_name if applicant else "未知"

    # Resolve approver name (最终审批人)
    if ticket.approver_id:
        r = await db.execute(select(User).where(User.id == ticket.approver_id))
        approver = r.scalar_one_or_none()
        data["approver_name"] = approver.display_name if approver else "未知"

    # Resolve instance name
    if ticket.instance_id:
        r = await db.execute(select(Instance).where(Instance.id == ticket.instance_id))
        inst = r.scalar_one_or_none()
        data["instance_name"] = inst.name if inst else "未知"

    # Resolve current approver (审批/执行阶段的当前待审核人)
    data["current_approver_name"] = None
    if ticket.status in ("reviewing", "approved", "executing"):
        pending_approval = await db.execute(
            select(TicketApproval)
            .where(
                TicketApproval.ticket_id == ticket.id,
                TicketApproval.action == "pending",
            )
            .order_by(TicketApproval.step_number)
            .limit(1)
        )
        pending = pending_approval.scalar_one_or_none()
        if pending:
            if pending.approver_id:
                r = await db.execute(select(User).where(User.id == pending.approver_id))
                approver_user = r.scalar_one_or_none()
                data["current_approver_name"] = approver_user.display_name if approver_user else None
            elif pending.approver_role:
                data["current_approver_name"] = pending.approver_role

    return data


async def _get_instance(db: AsyncSession, instance_id: int) -> Instance:
    """获取数据源实例，不存在则抛出 404。

    Args:
        db: 数据库会话
        instance_id: 实例ID

    Returns:
        Instance 对象

    Raises:
        HTTPException: 实例不存在
    """
    result = await db.execute(select(Instance).where(Instance.id == instance_id))
    instance = result.scalar_one_or_none()
    if not instance:
        raise HTTPException(status_code=404, detail="数据源不存在")
    return instance


async def _get_ticket(db: AsyncSession, ticket_id: int) -> Ticket:
    """获取工单，不存在则抛出 404。

    Args:
        db: 数据库会话
        ticket_id: 工单ID

    Returns:
        Ticket 对象

    Raises:
        HTTPException: 工单不存在
    """
    result = await db.execute(select(Ticket).where(Ticket.id == ticket_id))
    ticket = result.scalar_one_or_none()
    if not ticket:
        raise HTTPException(status_code=404, detail="工单不存在")
    return ticket


def _validate_ticket_content(data: TicketCreate) -> None:
    """验证工单内容安全性。

    Args:
        data: 工单创建数据

    Raises:
        HTTPException: 验证失败
    """
    # SQL 内容长度检查
    if len(data.sql_content) > MAX_QUERY_LENGTH:
        raise HTTPException(
            status_code=400,
            detail=f"SQL 内容过长（{len(data.sql_content)} 字符），最大允许 {MAX_QUERY_LENGTH} 字符",
        )

    # 检测 null 字节
    if "\x00" in data.sql_content:
        raise HTTPException(status_code=400, detail="SQL 内容包含非法字符（null 字节）")

    # 检测零宽字符（可能的注入攻击）
    zero_width_chars = ["\u200b", "\u200c", "\u200d", "\ufeff"]
    for char in zero_width_chars:
        if char in data.sql_content:
            raise HTTPException(
                status_code=400,
                detail="SQL 内容包含非法的零宽 Unicode 字符",
            )

    # 回滚 SQL 长度检查
    if data.rollback_sql and len(data.rollback_sql) > MAX_QUERY_LENGTH:
        raise HTTPException(
            status_code=400,
            detail=f"回滚 SQL 过长（{len(data.rollback_sql)} 字符），最大允许 {MAX_QUERY_LENGTH} 字符",
        )


# ===== API 端点 =====


@router.get("")
async def list_tickets(
    page: int = Query(1, ge=1, description="页码"),
    page_size: int = Query(10, ge=1, le=100, description="每页数量"),
    status: Optional[str] = None,
    db_type: Optional[str] = None,
    keyword: Optional[str] = None,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单列表。

    - admin/dba 可查看所有工单
    - developer 只能查看自己的工单
    """
    stmt = select(Ticket)

    # 权限过滤: developer 只能看到自己的工单
    if current_user.role == "developer":
        stmt = stmt.where(Ticket.applicant_id == current_user.id)

    # 状态过滤
    if status:
        # 验证状态值合法性
        valid_statuses = [s.value for s in TicketStatus]
        if status not in valid_statuses:
            raise HTTPException(status_code=400, detail=f"无效的状态值: {status}")
        stmt = stmt.where(Ticket.status == status)

    if db_type:
        stmt = stmt.where(Ticket.db_type == db_type)

    if keyword:
        # 限制关键词长度防止 DoS
        keyword = keyword[:100]
        stmt = stmt.where(
            or_(
                Ticket.title.contains(keyword),
                Ticket.sql_content.contains(keyword),
            )
        )

    # 总数查询
    total_stmt = select(func.count()).select_from(stmt.subquery())
    total_result = await db.execute(total_stmt)
    total = total_result.scalar() or 0

    # 分页查询
    stmt = (
        stmt.order_by(Ticket.create_time.desc())
        .offset((page - 1) * page_size)
        .limit(page_size)
    )
    result = await db.execute(stmt)
    tickets = result.scalars().all()

    items = []
    for t in tickets:
        items.append(await _enrich_ticket(t, db))

    return {
        "total": total,
        "page": page,
        "page_size": page_size,
        "items": items,
    }


@router.post("", status_code=201)
async def create_ticket(
    data: TicketCreate,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """创建工单。

    流程:
    1. 验证数据源存在和权限
    2. 验证工单内容安全性
    3. 自动 SQL 审核
    4. 创建工单记录
    5. 如有多级审批流，创建审批步骤
    """
    # 1. 验证数据源
    instance = await _get_instance(db, data.instance_id)

    # 2. 权限检查
    try:
        await check_instance_access(current_user, instance, db)
    except HTTPException:
        raise HTTPException(status_code=403, detail="您没有权限对该数据源提交变更工单")

    await check_instance_permission(current_user, instance, "ticket:create", db)

    # 3. 验证工单内容安全性
    _validate_ticket_content(data)

    # 3.5 EXPLAIN 预检（大表检测合并到 risk_evaluator，不再单独查表大小）
    table_sizes = {}
    explain_warnings = []
    try:
        from app.services.explain_preview import run_explain_preview
        import asyncio as _asyncio
        explain_result = await _asyncio.wait_for(
            run_explain_preview(data.sql_content, instance, data.target_database),
            timeout=8.0,
        )
        explain_warnings = explain_result.warnings
        table_sizes = explain_result.table_sizes or {}
    except Exception as e:
        import asyncio as _asyncio
        logger.warning("EXPLAIN 预检失败(非致命): %s", e)

    # 4. 自动审核 SQL（带超时保护）
    env = "production" if instance.env == "production" else "development"
    v2_engine = SQLAuditEngineV2(db_session=db, env=env)
    try:
        v2_report = await _asyncio.wait_for(
            v2_engine.audit(data.sql_content, db_type=data.db_type, instance_id=data.instance_id),
            timeout=10.0,
        )
    except _asyncio.TimeoutError:
        logger.warning("SQL 审核超时(10s)，跳过审核: ticket title=%s", data.title)
        v2_report = None
    except Exception as e:
        logger.error("SQL 审核失败: %s", e)
        v2_report = None

    # 5. 计算风险等级
    from app.services.risk_evaluator import evaluate_risk_level
    audit_findings_raw = v2_report.to_dict().get("findings", []) if v2_report else []
    import sqlparse as _sqlparse
    stmt_list = [s.strip() for s in _sqlparse.split(data.sql_content) if s.strip()]
    risk_level = evaluate_risk_level(
        sql_content=data.sql_content,
        db_type=data.db_type,
        sql_type=data.sql_type or "",
        audit_findings=audit_findings_raw,
        statement_count=len(stmt_list),
        table_sizes=table_sizes,
    )

    # EXPLAIN 结果可能升级风险等级
    if explain_warnings and risk_level == "low":
        risk_level = "medium"

    # 6. 匹配审批流 — 优先按 instance.workflow_id，其次按 risk_level 匹配默认流
    workflow = None
    if instance.workflow_id:
        wf_result = await db.execute(
            select(WorkflowDefinition).where(
                WorkflowDefinition.id == instance.workflow_id,
                WorkflowDefinition.is_active == True,
            )
        )
        workflow = wf_result.scalar_one_or_none()
    if not workflow:
        default_wf_result = await db.execute(
            select(WorkflowDefinition).where(
                WorkflowDefinition.is_default == True,
                WorkflowDefinition.is_active == True,
            )
        )
        workflow = default_wf_result.scalar_one_or_none()

    initial_status = TicketStatus.REVIEWING.value if workflow else TicketStatus.PENDING.value

    # 7. 创建工单
    ticket = Ticket(
        title=data.title,
        db_type=data.db_type,
        instance_id=data.instance_id,
        target_database=data.target_database,
        sql_content=data.sql_content,
        rollback_sql=data.rollback_sql,
        reason=data.reason,
        priority=data.priority,
        risk_level=risk_level,
        workflow_id=workflow.id if workflow else None,
        exec_strategy=data.exec_strategy or "stop_on_error",
        applicant_id=current_user.id,
        status=initial_status,
        audit_result=json.dumps(v2_report.to_dict(), ensure_ascii=False) if v2_report and v2_report.findings else None,
        scheduled_at=data.scheduled_at,
    )
    db.add(ticket)
    await db.flush()  # flush to get ticket.id

    # 生成工单编号
    ticket.ticket_no = _generate_ticket_no(ticket.id)
    await db.flush()

    # 7. 创建审批步骤（多级审批流）
    if workflow:
        wf_steps_result = await db.execute(
            select(WorkflowStep)
            .where(WorkflowStep.workflow_id == workflow.id)
            .order_by(WorkflowStep.step_number)
        )
        wf_steps = wf_steps_result.scalars().all()
        for step in wf_steps:
            approval = TicketApproval(
                ticket_id=ticket.id,
                step_number=step.step_number,
                step_name=step.name,
                approver_role=step.approver_role,
                action="pending",
            )
            db.add(approval)
        await db.flush()

    # 8. 创建 SQL 逐条执行记录
    from app.models.ticket_sql_item import TicketSqlItem
    for i, stmt in enumerate(stmt_list, start=1):
        stmt_type = _classify_sql_type(stmt)
        sql_item = TicketSqlItem(
            ticket_id=ticket.id,
            seq=i,
            sql_text=stmt,
            sql_type=stmt_type,
            status="pending",
        )
        db.add(sql_item)
    await db.flush()

    # 9. 记录审计日志
    audit_detail = ""
    if v2_report:
        audit_detail = f"SQL审核评分: {v2_report.score}, 通过: {v2_report.passed}, 规则数: {len(v2_report.findings)}"
    await AuditLogService.log(
        db, user_id=current_user.id, action="CREATE_TICKET",
        target_type="ticket", target_id=ticket.id,
        detail=audit_detail or "工单创建",
    )

    await db.commit()
    await db.refresh(ticket)

    # 9. 发送创建通知
    try:
        await _send_ticket_notification(db, ticket, "ticket_created")
    except Exception as notify_err:
        logger.error("创建通知发送失败: %s", notify_err)

    result = await _enrich_ticket(ticket, db)
    if v2_report:
        result["audit_report"] = v2_report.to_dict()
    return result


@router.get("/statistics")
async def ticket_statistics(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单统计信息。"""
    stmt = select(Ticket.status, func.count(Ticket.id)).group_by(Ticket.status)
    result = await db.execute(stmt)
    stats = {row[0]: row[1] for row in result.all()}

    total = sum(stats.values())
    return {
        "total": total,
        "pending": stats.get("pending", 0),
        "reviewing": stats.get("reviewing", 0),
        "approved": stats.get("approved", 0),
        "rejected": stats.get("rejected", 0),
        "executing": stats.get("executing", 0),
        "success": stats.get("success", 0),
        "failed": stats.get("failed", 0),
        "rollback": stats.get("rollback", 0),
    }


@router.post("/audit")
async def audit_sql(
    data: AuditRequest,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """SQL 审核接口（独立调用）。"""
    # 验证实例存在
    instance = await _get_instance(db, data.instance_id)

    env = "production" if instance.env == "production" else "development"
    db_type = instance.db_type or "mysql"

    # 使用 V2 引擎进行审核
    v2_engine = SQLAuditEngineV2(db_session=db, env=env)
    try:
        report = await v2_engine.audit(data.sql_content, db_type=db_type)
    except Exception as e:
        logger.error("SQL 审核异常: %s", e)
        raise HTTPException(status_code=500, detail=f"审核引擎异常: {e}")

    return {
        "score": report.score,
        "passed": report.passed,
        "has_warnings": report.has_warnings,
        "risk_level": getattr(report, 'risk_level', 'unknown'),
        "summary": getattr(report, 'summary', ''),
        "findings": [
            {
                "rule": getattr(f, 'rule_code', getattr(f, 'rule', 'unknown')),
                "level": f.level.value,
                "message": f.message,
                "risk_level": getattr(f, 'risk_level', 'medium'),
                "suggestion": getattr(f, 'suggestion', ''),
            }
            for f in report.findings
        ],
    }


@router.get("/{ticket_id}")
async def get_ticket(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单详情。"""
    ticket = await _get_ticket(db, ticket_id)

    # 权限检查: developer 只能查看自己的工单
    if current_user.role == "developer" and ticket.applicant_id != current_user.id:
        raise HTTPException(status_code=403, detail="无权查看该工单")

    return await _enrich_ticket(ticket, db)


@router.get("/{ticket_id}/approvals")
async def get_ticket_approvals(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单的审批进度（多级审批流）。"""
    ticket = await _get_ticket(db, ticket_id)

    # 权限检查
    if current_user.role == "developer" and ticket.applicant_id != current_user.id:
        raise HTTPException(status_code=403, detail="无权查看该工单")

    approvals_result = await db.execute(
        select(TicketApproval)
        .where(TicketApproval.ticket_id == ticket_id)
        .order_by(TicketApproval.step_number)
    )
    approvals = approvals_result.scalars().all()

    return [
        {
            "id": a.id,
            "step_number": a.step_number,
            "step_name": a.step_name,
            "approver_role": a.approver_role,
            "action": a.action,
            "approver_id": a.approver_id,
            "comment": a.comment,
            "created_at": a.created_at.isoformat() if a.created_at else None,
            "updated_at": a.updated_at.isoformat() if a.updated_at else None,
        }
        for a in approvals
    ]


@router.post("/{ticket_id}/review")
async def review_ticket(
    ticket_id: int,
    data: TicketReview,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """审核工单。

    支持多级审批流:
    - 通过: 按顺序审批，所有步骤通过后状态变为 approved
    - 拒绝: 立即拒绝整个工单
    """
    ticket = await _get_ticket(db, ticket_id)

    # 状态机验证: 只能审批 pending 或 reviewing 状态的工单
    if ticket.status not in (TicketStatus.PENDING.value, TicketStatus.REVIEWING.value):
        raise HTTPException(
            status_code=400,
            detail=f"工单状态为 {ticket.status}，无法审核。只能审批 pending/reviewing 状态的工单"
        )

    if data.action == "approve":
        # 检查多级审批流
        pending_approvals_result = await db.execute(
            select(TicketApproval)
            .where(TicketApproval.ticket_id == ticket_id)
            .order_by(TicketApproval.step_number)
        )
        pending_approvals = pending_approvals_result.scalars().all()

        if pending_approvals:
            # 多级审批: 找到当前待审批步骤
            current_step = None
            for pa in pending_approvals:
                if pa.action == "pending":
                    current_step = pa
                    break

            if current_step:
                # 审批当前步骤
                current_step.action = "approved"
                current_step.approver_id = current_user.id
                current_step.comment = data.comment or "审批通过"

                # 检查是否还有后续待审批步骤
                has_next = any(
                    pa.action == "pending"
                    for pa in pending_approvals
                    if pa.id != current_step.id
                )
                if has_next:
                    new_status = TicketStatus.REVIEWING.value
                else:
                    new_status = TicketStatus.APPROVED.value
            else:
                # 所有步骤已处理
                new_status = TicketStatus.APPROVED.value
        else:
            # 无审批流 - 单步审批
            new_status = TicketStatus.APPROVED.value
    else:
        # 拒绝: 标记所有待审批步骤为拒绝
        pending_approvals_result = await db.execute(
            select(TicketApproval)
            .where(TicketApproval.ticket_id == ticket_id, TicketApproval.action == "pending")
        )
        for pa in pending_approvals_result.scalars().all():
            pa.action = "rejected"
            pa.approver_id = current_user.id
            pa.comment = data.comment or "审批拒绝"

        new_status = TicketStatus.REJECTED.value

    # 验证状态转换合法性
    if not _validate_status_transition(ticket.status, new_status):
        raise HTTPException(
            status_code=400,
            detail=f"非法的状态转换: {ticket.status} -> {new_status}"
        )

    ticket.status = new_status
    ticket.approver_id = current_user.id
    ticket.review_time = datetime.now(timezone.utc)
    ticket.audit_result = data.comment

    await AuditLogService.log(
        db, user_id=current_user.id, action="REVIEW_TICKET",
        target_type="ticket", target_id=ticket.id,
        detail=f"审核动作: {data.action}, 备注: {data.comment}, 新状态: {new_status}",
    )

    await db.commit()
    await db.refresh(ticket)

    # 发送审批通知（仅审批通过时通知，拒绝不通知）
    if data.action == "approve":
        try:
            await _send_ticket_notification(db, ticket, "ticket_approved", {
                "approver": current_user.display_name,
                "comment": data.comment or "审批通过",
            })
        except Exception as notify_err:
            logger.error("审批通知发送失败: %s", notify_err)

    return await _enrich_ticket(ticket, db)


@router.get("/{ticket_id}/timeline")
async def get_ticket_timeline(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单时间线。"""
    ticket = await _get_ticket(db, ticket_id)

    if current_user.role == "developer" and ticket.applicant_id != current_user.id:
        raise HTTPException(status_code=403, detail="无权查看该工单")

    # 获取审计日志
    log_stmt = (
        select(AuditLog)
        .where(AuditLog.target_type == "ticket", AuditLog.target_id == ticket_id)
        .order_by(AuditLog.created_at.asc())
    )
    log_result = await db.execute(log_stmt)
    logs = log_result.scalars().all()

    timeline = []

    # 创建事件
    applicant_name = "未知"
    if ticket.applicant_id:
        r = await db.execute(select(User).where(User.id == ticket.applicant_id))
        applicant = r.scalar_one_or_none()
        if applicant:
            applicant_name = applicant.display_name

    timeline.append({
        "action": "CREATE_TICKET",
        "label": "创建工单",
        "user": applicant_name,
        "time": ticket.create_time.isoformat() if ticket.create_time else None,
        "detail": "提交 SQL 变更工单",
    })

    # 审计日志事件
    for log in logs:
        if log.action == "CREATE_TICKET":
            continue
        r = await db.execute(select(User).where(User.id == log.user_id))
        u = r.scalar_one_or_none()
        uname = u.display_name if u else "未知"

        label_map = {
            "REVIEW_TICKET": "审核工单",
            "EXECUTE_TICKET": "执行工单",
            "CANCEL_TICKET": "取消工单",
            "ROLLBACK_TICKET": "回滚工单",
        }
        timeline.append({
            "action": log.action,
            "label": label_map.get(log.action, log.action),
            "user": uname,
            "time": log.created_at.isoformat() if log.created_at else None,
            "detail": log.detail,
        })

    # 基于状态的合成事件
    if ticket.review_time:
        has_review = any(t["action"] == "REVIEW_TICKET" for t in timeline)
        if not has_review:
            approver_name = "未知"
            if ticket.approver_id:
                r = await db.execute(select(User).where(User.id == ticket.approver_id))
                a = r.scalar_one_or_none()
                if a:
                    approver_name = a.display_name
            timeline.append({
                "action": "REVIEW_TICKET",
                "label": "审核工单",
                "user": approver_name,
                "time": ticket.review_time.isoformat() if ticket.review_time else None,
                "detail": "工单状态变更为 " + str(ticket.status),
            })

    if ticket.execute_time:
        has_exec = any(t["action"] == "EXECUTE_TICKET" for t in timeline)
        if not has_exec:
            timeline.append({
                "action": "EXECUTE_TICKET",
                "label": "执行工单",
                "user": "系统",
                "time": ticket.execute_time.isoformat() if ticket.execute_time else None,
                "detail": ticket.execute_result or "执行完成",
            })

    return {"ticket_id": ticket_id, "timeline": timeline}


@router.get("/{ticket_id}/sql-items")
async def get_ticket_sql_items(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """获取工单 SQL 逐条执行进度。"""
    from app.models.ticket_sql_item import TicketSqlItem

    result = await db.execute(
        select(TicketSqlItem)
        .where(TicketSqlItem.ticket_id == ticket_id)
        .order_by(TicketSqlItem.seq)
    )
    items = result.scalars().all()

    return {
        "ticket_id": ticket_id,
        "total": len(items),
        "items": [
            {
                "id": item.id,
                "seq": item.seq,
                "sql_text": item.sql_text,
                "sql_type": item.sql_type,
                "status": item.status,
                "affected_rows": item.affected_rows,
                "duration_ms": item.duration_ms,
                "error_message": item.error_message,
                "started_at": item.started_at.isoformat() if item.started_at else None,
                "finished_at": item.finished_at.isoformat() if item.finished_at else None,
            }
            for item in items
        ],
        "progress": {
            "total": len(items),
            "success": sum(1 for i in items if i.status == "success"),
            "failed": sum(1 for i in items if i.status == "failed"),
            "running": sum(1 for i in items if i.status == "running"),
            "pending": sum(1 for i in items if i.status == "pending"),
            "skipped": sum(1 for i in items if i.status == "skipped"),
        },
    }


@router.post("/{ticket_id}/cancel")
async def cancel_ticket(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """取消工单。

    只有申请人或管理员可以取消 pending/reviewing 状态的工单。
    """
    ticket = await _get_ticket(db, ticket_id)

    # 权限检查
    if ticket.applicant_id != current_user.id and current_user.role != "admin":
        raise HTTPException(status_code=403, detail="只有申请人或管理员可以取消工单")

    # 状态检查
    if ticket.status not in (TicketStatus.PENDING.value, TicketStatus.REVIEWING.value):
        raise HTTPException(status_code=400, detail="只能取消待审批或审批中的工单")

    # 状态转换
    new_status = TicketStatus.REJECTED.value
    if not _validate_status_transition(ticket.status, new_status):
        raise HTTPException(
            status_code=400,
            detail=f"非法的状态转换: {ticket.status} -> {new_status}"
        )

    ticket.status = new_status
    ticket.audit_result = "工单被取消"

    # 更新审批步骤状态
    pending_approvals_result = await db.execute(
        select(TicketApproval)
        .where(TicketApproval.ticket_id == ticket_id, TicketApproval.action == "pending")
    )
    for pa in pending_approvals_result.scalars().all():
        pa.action = "cancelled"
        pa.comment = "工单被取消"

    await AuditLogService.log(
        db, user_id=current_user.id, action="CANCEL_TICKET",
        target_type="ticket", target_id=ticket.id,
        detail="取消工单",
    )

    await db.commit()
    await db.refresh(ticket)
    return await _enrich_ticket(ticket, db)


@router.post("/{ticket_id}/rollback")
async def rollback_ticket(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """回滚工单。

    只能回滚 success 或 failed 状态的工单。
    """
    ticket = await _get_ticket(db, ticket_id)

    if ticket.status not in (TicketStatus.SUCCESS.value, TicketStatus.FAILED.value):
        raise HTTPException(status_code=400, detail="只能回滚已执行（成功或失败）的工单")

    # 状态转换
    new_status = TicketStatus.ROLLBACK.value
    if not _validate_status_transition(ticket.status, new_status):
        raise HTTPException(
            status_code=400,
            detail=f"非法的状态转换: {ticket.status} -> {new_status}"
        )

    rollback_sql = ticket.rollback_sql or "未提供回滚 SQL"

    await AuditLogService.log(
        db, user_id=current_user.id, action="ROLLBACK_TICKET",
        target_type="ticket", target_id=ticket.id,
        detail=f"请求回滚工单，回滚SQL: {rollback_sql[:200]}",
    )

    ticket.status = new_status
    await db.commit()
    await db.refresh(ticket)

    return {
        "message": "回滚请求已记录，请手动执行以下回滚 SQL",
        "ticket_id": ticket_id,
        "rollback_sql": rollback_sql,
        "status": ticket.status,
    }


@router.post("/{ticket_id}/execute")
async def execute_ticket(
    ticket_id: int,
    confirm: Optional[TicketExecuteConfirm] = None,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """执行工单。

    使用多数据库工单执行引擎，按 db_type 自动分发到对应执行器。

    执行流程:
    1. 验证工单状态为 approved
    2. 二次确认（可选）
    3. 更新状态为 executing
    4. 执行变更
    5. 更新结果和状态
    6. 记录审计日志
    7. 发送通知

    Args:
        ticket_id: 工单 ID
        confirm: 二次确认参数
        db: 数据库会话
        current_user: 当前用户（需要 admin 或 dba 角色）

    Returns:
        执行后的工单详情，包含执行报告
    """
    # 1. 查询工单
    ticket = await _get_ticket(db, ticket_id)

    # 2. 状态检查
    if ticket.status != TicketStatus.APPROVED.value:
        raise HTTPException(status_code=400, detail="只能执行已审批的工单")

    # 3. 二次确认检查
    if confirm and not confirm.confirmed:
        raise HTTPException(status_code=400, detail="未确认执行，操作已取消")

    # 3.1 高危操作强制二次确认
    risk_level = getattr(ticket, "risk_level", "low")
    if risk_level in ("high", "critical"):
        if not confirm or not confirm.confirmed:
            from app.services.risk_evaluator import RISK_LEVEL_CONFIG
            risk_cfg = RISK_LEVEL_CONFIG.get(risk_level, {})
            raise HTTPException(
                status_code=409,
                detail=f"该工单风险等级为「{risk_cfg.get('label', risk_level)}」，需要二次确认后才能执行。请传入 confirmed=true",
            )

    # 4. 查询数据源实例
    instance = await _get_instance(db, ticket.instance_id)

    # 5. 权限检查
    await check_instance_permission(current_user, instance, "ticket:execute", db)

    # 5.1 维护窗口检查 — 非定时工单检查是否在维护窗口内
    if not ticket.scheduled_at:
        maintenance_window = await _check_maintenance_window(db)
        if maintenance_window:
            raise HTTPException(
                status_code=403,
                detail=f"当前不在维护窗口内，允许执行时间: {maintenance_window}",
            )

    # 6. 定时执行：如果 scheduled_at 在未来，改为 scheduled 状态
    if ticket.scheduled_at:
        now = datetime.now(timezone.utc)
        scheduled_aware = ticket.scheduled_at.replace(tzinfo=timezone.utc) if ticket.scheduled_at.tzinfo is None else ticket.scheduled_at
        if scheduled_aware > now:
            if not _validate_status_transition(ticket.status, TicketStatus.SCHEDULED.value):
                raise HTTPException(status_code=400, detail=f"非法的状态转换: {ticket.status} -> scheduled")
            ticket.status = TicketStatus.SCHEDULED.value
            await db.commit()
            await db.refresh(ticket)

            # 启动后台定时执行
            from app.services.ticket_scheduler import schedule_ticket_execution
            await schedule_ticket_execution(ticket.id, scheduled_aware)

            ticket_data = await _enrich_ticket(ticket, db)
            return ticket_data

    # 7. 状态转换: approved -> executing
    if not _validate_status_transition(ticket.status, TicketStatus.EXECUTING.value):
        raise HTTPException(
            status_code=400,
            detail=f"非法的状态转换: {ticket.status} -> {TicketStatus.EXECUTING.value}"
        )

    ticket.status = TicketStatus.EXECUTING.value
    await db.commit()
    await db.refresh(ticket)

    # 8. 使用多数据库执行引擎
    from app.services.ticket_executor import TicketExecutor
    executor = TicketExecutor()

    try:
        # 解密密码
        instance.password = decrypt_password(instance.password)

        # 执行工单
        report = await executor.execute(ticket, instance)

        # 8. 更新工单状态和结果
        if report.status == "success":
            new_status = TicketStatus.SUCCESS.value
        else:
            new_status = TicketStatus.FAILED.value

        # 验证状态转换
        if _validate_status_transition(TicketStatus.EXECUTING.value, new_status):
            ticket.status = new_status
        else:
            ticket.status = TicketStatus.FAILED.value

        ticket.execute_result = report.to_json()
        ticket.execute_time = datetime.now(timezone.utc)

        # 8.1 更新 SQL 逐条执行记录
        await _update_sql_items_from_report(db, ticket.id, report)

        # 9. 记录执行日志
        log_detail = (
            f"执行结果: {report.status}, 影响行数: {report.affected_rows}, "
            f"耗时: {report.duration_ms}ms, 验证通过: {report.validation_passed}"
        )
        if report.errors:
            log_detail += f", 错误: {'; '.join(report.errors[:3])}"
        if confirm and confirm.comment:
            log_detail += f", 执行备注: {confirm.comment}"

        await AuditLogService.log(
            db,
            user_id=current_user.id,
            action="EXECUTE_TICKET",
            target_type="ticket",
            target_id=ticket.id,
            detail=log_detail,
        )

        # 10. 发送通知
        try:
            await _send_execution_notification(db, ticket, report)
        except Exception as notify_err:
            logger.error("执行通知发送失败: %s", notify_err)
            # 通知失败不应影响执行结果

    except Exception as e:
        logger.exception("工单 %d 执行异常", ticket_id)
        ticket.status = TicketStatus.FAILED.value
        ticket.execute_result = json.dumps({
            "status": "failed",
            "errors": [f"{type(e).__name__}: {e}"],
        }, ensure_ascii=False)
        ticket.execute_time = datetime.now(timezone.utc)

        # 标记所有 pending SQL items 为 failed
        await _mark_sql_items_failed(db, ticket.id, str(e))

        await AuditLogService.log(
            db,
            user_id=current_user.id,
            action="EXECUTE_TICKET",
            target_type="ticket",
            target_id=ticket.id,
            detail=f"执行异常: {type(e).__name__}: {e}",
        )

    # 11. 提交事务并返回
    await db.commit()
    await db.refresh(ticket)

    # 构建响应
    ticket_data = await _enrich_ticket(ticket, db)

    # 尝试解析执行报告
    try:
        exec_report = json.loads(ticket.execute_result) if ticket.execute_result else {}
        if isinstance(exec_report, dict):
            from app.schemas.execution import ExecutionReportResponse
            ticket_data["execution_report"] = ExecutionReportResponse(
                status=exec_report.get("status", "unknown"),
                affected_rows=exec_report.get("affected_rows", 0),
                duration_ms=exec_report.get("duration_ms", 0),
                validation_passed=exec_report.get("validation_passed", False),
                warnings=exec_report.get("warnings", []),
                errors=exec_report.get("errors", []),
                raw_output=exec_report.get("raw_output"),
                before_snapshot_summary=exec_report.get("before_snapshot"),
                after_snapshot_summary=exec_report.get("after_snapshot"),
            )
    except Exception:
        ticket_data["execution_report"] = None

    return ticket_data


async def _get_user_name(db: AsyncSession, user_id: Optional[int]) -> str:
    """获取用户显示名称。"""
    if not user_id:
        return "系统"
    result = await db.execute(select(User).where(User.id == user_id))
    user = result.scalar_one_or_none()
    return user.display_name if user else "未知"


async def _get_instance_name(db: AsyncSession, instance_id: Optional[int]) -> str:
    """获取实例名称。"""
    if not instance_id:
        return "未知实例"
    result = await db.execute(select(Instance).where(Instance.id == instance_id))
    inst = result.scalar_one_or_none()
    return inst.name if inst else "未知实例"


async def _get_enabled_channels(db: AsyncSession) -> list:
    """获取已启用的通知渠道。"""
    from app.models.notification import NotificationChannel
    result = await db.execute(
        select(NotificationChannel).where(NotificationChannel.is_enabled == True)
    )
    return result.scalars().all()


async def _send_ticket_notification(
    db: AsyncSession, ticket: Ticket, event_type: str,
    extra_data: Optional[Dict[str, Any]] = None,
) -> None:
    """通用工单通知发送。

    Args:
        db: 数据库会话
        ticket: 工单对象
        event_type: 事件类型 (ticket_created / ticket_approved / ticket_rejected / ticket_executed / ticket_failed)
        extra_data: 额外模板数据 (如 approver, operator, error 等)
    """
    from app.services.notification_sender import NotificationSender

    channels = await _get_enabled_channels(db)
    if not channels:
        return

    # 获取关联信息
    applicant_name = await _get_user_name(db, ticket.applicant_id)
    instance_name = await _get_instance_name(db, ticket.instance_id)
    sql_preview = ticket.sql_content[:100] + "..." if len(ticket.sql_content) > 100 else ticket.sql_content

    # Redis database 格式化: "0" → "db0"
    target_db = ticket.target_database or ""
    if ticket.db_type == "redis" and target_db.isdigit():
        target_db = f"db{target_db}"

    notification_data = {
        "title": ticket.title,
        "ticket_id": ticket.id,
        "ticket_no": ticket.ticket_no or str(ticket.id),
        "db_type": ticket.db_type,
        "target_database": target_db,
        "instance_name": instance_name,
        "sql_preview": sql_preview,
        "applicant": applicant_name,
        "approver": "未知",
        "operator": "系统",
        "comment": "",
        "result": "",
        "duration": 0,
        "affected_rows": 0,
        "error": "",
    }

    # 合并额外数据
    if extra_data:
        notification_data.update(extra_data)

    sender = NotificationSender()
    await sender.notify_ticket_event(
        ticket_id=ticket.id,
        event_type=event_type,
        channels=channels,
        ticket_data=notification_data,
    )


async def _send_execution_notification(
    db: AsyncSession, ticket: Ticket, report: "ExecutionReport"
) -> None:
    """发送工单执行完成通知（兼容旧调用）。"""
    from app.services.notification_sender import NotificationSender

    channels = await _get_enabled_channels(db)
    if not channels:
        return

    event_type = "ticket_executed" if report.status == "success" else "ticket_failed"
    operator_name = await _get_user_name(db, ticket.approver_id)
    instance_name = await _get_instance_name(db, ticket.instance_id)
    applicant_name = await _get_user_name(db, ticket.applicant_id)
    sql_preview = ticket.sql_content[:100] + "..." if len(ticket.sql_content) > 100 else ticket.sql_content

    # Redis database 格式化: "0" → "db0"
    target_db = ticket.target_database or ""
    if ticket.db_type == "redis" and target_db.isdigit():
        target_db = f"db{target_db}"

    notification_data = {
        "title": ticket.title,
        "ticket_id": ticket.id,
        "ticket_no": ticket.ticket_no or str(ticket.id),
        "db_type": ticket.db_type,
        "target_database": target_db,
        "instance_name": instance_name,
        "sql_preview": sql_preview,
        "applicant": applicant_name,
        "operator": operator_name,
        "result": report.status,
        "duration": report.duration_ms,
        "affected_rows": report.affected_rows,
        "error": "; ".join(report.errors[:3]) if report.errors else "",
        "approver": operator_name,
        "comment": "",
    }

    sender = NotificationSender()
    await sender.notify_ticket_event(
        ticket_id=ticket.id,
        event_type=event_type,
        channels=channels,
        ticket_data=notification_data,
    )


# ===== 定时任务管理 =====

@router.get("/scheduled/list")
async def list_scheduled_tickets(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """列出所有定时执行中的工单。"""
    result = await db.execute(
        select(Ticket)
        .where(Ticket.status == TicketStatus.SCHEDULED.value)
        .order_by(Ticket.scheduled_at.asc())
    )
    tickets = result.scalars().all()
    data = []
    for t in tickets:
        inst_result = await db.execute(select(Instance).where(Instance.id == t.instance_id))
        inst = inst_result.scalar_one_or_none()
        data.append({
            "id": t.id,
            "ticket_no": t.ticket_no,
            "title": t.title,
            "db_type": t.db_type,
            "instance_name": inst.name if inst else "未知",
            "instance_db_type": inst.db_type if inst else "",
            "target_database": t.target_database,
            "sql_content": t.sql_content[:200] + "..." if len(t.sql_content) > 200 else t.sql_content,
            "status": t.status,
            "scheduled_at": t.scheduled_at.isoformat() if t.scheduled_at else None,
            "priority": t.priority,
            "create_time": t.create_time.isoformat() if t.create_time else None,
        })
    return {"items": data, "total": len(data)}


@router.post("/{ticket_id}/cancel-schedule")
async def cancel_scheduled_ticket(
    ticket_id: int,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_role("admin", "dba")),
):
    """取消定时执行，将工单状态改回 approved。"""
    ticket = await _get_ticket(db, ticket_id)
    if ticket.status != TicketStatus.SCHEDULED.value:
        raise HTTPException(status_code=400, detail="只能取消定时执行中的工单")

    if not _validate_status_transition(ticket.status, TicketStatus.APPROVED.value):
        raise HTTPException(status_code=400, detail="非法的状态转换")

    # 取消后台任务
    from app.services.ticket_scheduler import cancel_ticket_execution
    cancel_ticket_execution(ticket.id)

    ticket.status = TicketStatus.APPROVED.value
    await db.commit()
    await db.refresh(ticket)

    await AuditLogService.log(
        db, user_id=current_user.id, action="CANCEL_SCHEDULED_TICKET",
        target_type="ticket", target_id=ticket.id,
        detail=f"取消定时执行: {ticket.scheduled_at}",
    )

    return {"message": "已取消定时执行", "ticket_id": ticket_id, "status": ticket.status}