package handlers

import (
	"bytes"
	"context"
	"fmt"
	"net/http"
	"os/exec"
	"strconv"
	"time"

	"ezops/internal/models"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

// runLocal executes a script or shell command locally on the AIOps host and
// returns the combined stdout+stderr output, the process exit code (0 = success)
// and the wall-clock duration in milliseconds. A timeout prevents runaway jobs.
func runLocal(scriptType, content string, timeoutSec int) (output string, exitCode int, durationMs int) {
	start := time.Now()
	timeout := time.Duration(timeoutSec) * time.Second
	if timeout <= 0 {
		timeout = 300 * time.Second
	}
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	var cmd *exec.Cmd
	switch scriptType {
	case "python":
		cmd = exec.CommandContext(ctx, "python3", "-c", content)
	default: // shell / command / "" → run via bash
		cmd = exec.CommandContext(ctx, "bash", "-c", content)
	}

	var out bytes.Buffer
	cmd.Stdout = &out
	cmd.Stderr = &out

	err := cmd.Run()
	durationMs = int(time.Since(start).Milliseconds())
	output = out.String()

	if ctx.Err() == context.DeadlineExceeded {
		output += fmt.Sprintf("\n[超时] 执行超过 %d 秒被终止", timeoutSec)
		return output, -1, durationMs
	}
	if err != nil {
		if exitError, ok := err.(*exec.ExitError); ok {
			exitCode = exitError.ExitCode()
		} else {
			exitCode = -1
			output += "\n" + err.Error()
		}
		return output, exitCode, durationMs
	}
	return output, 0, durationMs
}

// AutomationHandler 自动化运维处理器
type AutomationHandler struct {
	db *gorm.DB
}

// NewAutomationHandler 创建自动化运维处理器
func NewAutomationHandler(db *gorm.DB) *AutomationHandler {
	return &AutomationHandler{db: db}
}

// ListCronJobs 获取定时任务列表
// @Summary 获取定时任务列表
// @Description 获取所有定时任务列表
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param page query int false "页码"
// @Param page_size query int false "每页数量"
// @Success 200 {object} models.Response{data=models.ListResponse}
// @Router /cron-jobs [get]
func (h *AutomationHandler) ListCronJobs(c *gin.Context) {
	var query models.PageQuery
	c.ShouldBindQuery(&query)

	var total int64
	h.db.Model(&models.CronJob{}).Count(&total)

	var jobs []models.CronJob
	h.db.Preload("Script").Offset(query.GetOffset()).Limit(query.GetLimit()).Find(&jobs)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data: models.ListResponse{
			List:  jobs,
			Total: total,
		},
	})
}

// GetCronJob 获取定时任务详情
// @Summary 获取定时任务详情
// @Description 获取指定定时任务的详细信息
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "任务ID"
// @Success 200 {object} models.Response{data=models.CronJob}
// @Router /cron-jobs/{id} [get]
func (h *AutomationHandler) GetCronJob(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var job models.CronJob
	if err := h.db.Preload("Script").First(&job, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "定时任务不存在",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data:    job,
	})
}

// CreateCronJob 创建定时任务
// @Summary 创建定时任务
// @Description 创建新定时任务
// @Tags 自动化运维
// @Accept json
// @Produce json
// @Security Bearer
// @Param request body models.CreateCronJobRequest true "创建请求"
// @Success 200 {object} models.Response{data=models.CronJob}
// @Router /cron-jobs [post]
func (h *AutomationHandler) CreateCronJob(c *gin.Context) {
	var req models.CreateCronJobRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	job := models.CronJob{
		Name:        req.Name,
		Description: req.Description,
		CronExpr:    req.CronExpr,
		Type:        req.Type,
		Content:     req.Content,
		ScriptID:    req.ScriptID,
		TargetType:  req.TargetType,
		Timeout:     req.Timeout,
		NotifyOn:    req.NotifyOn,
		Enabled:     true,
	}

	if job.Timeout == 0 {
		job.Timeout = 300
	}
	if job.NotifyOn == "" {
		job.NotifyOn = "failure"
	}

	if err := h.db.Create(&job).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "创建失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "创建成功",
		Data:    job,
	})
}

// UpdateCronJob 更新定时任务
// @Summary 更新定时任务
// @Description 更新指定定时任务
// @Tags 自动化运维
// @Accept json
// @Produce json
// @Security Bearer
// @Param id path int true "任务ID"
// @Param request body models.CreateCronJobRequest true "更新请求"
// @Success 200 {object} models.Response{data=models.CronJob}
// @Router /cron-jobs/{id} [put]
func (h *AutomationHandler) UpdateCronJob(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var req models.CreateCronJobRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	var job models.CronJob
	if err := h.db.First(&job, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "定时任务不存在",
		})
		return
	}

	updates := map[string]interface{}{
		"name":        req.Name,
		"description": req.Description,
		"cron_expr":   req.CronExpr,
		"type":        req.Type,
		"content":     req.Content,
		"script_id":   req.ScriptID,
		"target_type": req.TargetType,
		"timeout":     req.Timeout,
		"notify_on":   req.NotifyOn,
	}

	if err := h.db.Model(&job).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "更新失败",
		})
		return
	}

	h.db.Preload("Script").First(&job, id)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "更新成功",
		Data:    job,
	})
}

// DeleteCronJob 删除定时任务
// @Summary 删除定时任务
// @Description 删除指定定时任务
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "任务ID"
// @Success 200 {object} models.Response
// @Router /cron-jobs/{id} [delete]
func (h *AutomationHandler) DeleteCronJob(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	if err := h.db.Delete(&models.CronJob{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "删除失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "删除成功",
	})
}

// ToggleCronJob 切换定时任务状态
// @Summary 切换定时任务状态
// @Description 启用或禁用定时任务
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "任务ID"
// @Success 200 {object} models.Response{data=models.CronJob}
// @Router /cron-jobs/{id}/toggle [post]
func (h *AutomationHandler) ToggleCronJob(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var job models.CronJob
	if err := h.db.First(&job, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "定时任务不存在",
		})
		return
	}

	job.Enabled = !job.Enabled
	if err := h.db.Save(&job).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "操作失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "操作成功",
		Data:    job,
	})
}

// ExecuteCronJob 执行定时任务
// @Summary 执行定时任务
// @Description 手动执行定时任务
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "任务ID"
// @Success 200 {object} models.Response{data=models.TaskExecution}
// @Router /cron-jobs/{id}/execute [post]
func (h *AutomationHandler) ExecuteCronJob(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var job models.CronJob
	if err := h.db.First(&job, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "定时任务不存在",
		})
		return
	}

	// Resolve the content to execute. For type=script, load the linked Script.
	content := job.Content
	scriptType := "shell"
	if job.Type == "script" && job.ScriptID != nil {
		var script models.Script
		if err := h.db.First(&script, *job.ScriptID).Error; err == nil {
			content = script.Content
			scriptType = script.Type
			h.db.Model(&script).UpdateColumn("run_count", script.RunCount+1)
		}
	}

	now := time.Now()
	execution := models.TaskExecution{
		TaskType:   "cron",
		TaskID:     uint(id),
		TaskName:   job.Name,
		Status:     "running",
		TargetType: job.TargetType,
		Targets:    job.Targets,
		StartedAt:  &now,
	}
	if err := h.db.Create(&execution).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "创建执行记录失败",
		})
		return
	}

	// Execute locally on the AIOps host.
	output, exitCode, duration := runLocal(scriptType, content, job.Timeout)
	finishedAt := time.Now()
	status := "success"
	if exitCode != 0 {
		status = "failed"
	}

	h.db.Model(&execution).Updates(map[string]interface{}{
		"status":      status,
		"output":      output,
		"duration":    duration,
		"finished_at": finishedAt,
	})

	// Update cron job statistics.
	statsUpdates := map[string]interface{}{
		"last_run_at": now,
		"last_status": status,
		"run_count":   job.RunCount + 1,
	}
	if status == "success" {
		statsUpdates["success_count"] = job.SuccessCount + 1
	} else {
		statsUpdates["fail_count"] = job.FailCount + 1
	}
	h.db.Model(&job).Updates(statsUpdates)

	execution.Output = output
	execution.Status = status
	execution.Duration = duration
	execution.FinishedAt = &finishedAt

	msg := "执行成功"
	if status == "failed" {
		msg = "执行失败"
	}
	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: msg,
		Data:    execution,
	})
}

// ListScripts 获取脚本列表
// @Summary 获取脚本列表
// @Description 获取所有脚本列表
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param page query int false "页码"
// @Param page_size query int false "每页数量"
// @Success 200 {object} models.Response{data=models.ListResponse}
// @Router /scripts [get]
func (h *AutomationHandler) ListScripts(c *gin.Context) {
	var query models.PageQuery
	c.ShouldBindQuery(&query)

	var total int64
	h.db.Model(&models.Script{}).Count(&total)

	var scripts []models.Script
	h.db.Offset(query.GetOffset()).Limit(query.GetLimit()).Find(&scripts)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data: models.ListResponse{
			List:  scripts,
			Total: total,
		},
	})
}

// GetScript 获取脚本详情
// @Summary 获取脚本详情
// @Description 获取指定脚本的详细信息
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "脚本ID"
// @Success 200 {object} models.Response{data=models.Script}
// @Router /scripts/{id} [get]
func (h *AutomationHandler) GetScript(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var script models.Script
	if err := h.db.First(&script, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "脚本不存在",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data:    script,
	})
}

// CreateScript 创建脚本
// @Summary 创建脚本
// @Description 创建新脚本
// @Tags 自动化运维
// @Accept json
// @Produce json
// @Security Bearer
// @Param request body models.CreateScriptRequest true "创建请求"
// @Success 200 {object} models.Response{data=models.Script}
// @Router /scripts [post]
func (h *AutomationHandler) CreateScript(c *gin.Context) {
	var req models.CreateScriptRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	script := models.Script{
		Name:        req.Name,
		Code:        req.Code,
		Description: req.Description,
		Type:        req.Type,
		Content:     req.Content,
		Params:      req.Params,
		Timeout:     req.Timeout,
	}

	if script.Type == "" {
		script.Type = "shell"
	}
	if script.Timeout == 0 {
		script.Timeout = 300
	}

	if err := h.db.Create(&script).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "创建失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "创建成功",
		Data:    script,
	})
}

// UpdateScript 更新脚本
// @Summary 更新脚本
// @Description 更新指定脚本
// @Tags 自动化运维
// @Accept json
// @Produce json
// @Security Bearer
// @Param id path int true "脚本ID"
// @Param request body models.CreateScriptRequest true "更新请求"
// @Success 200 {object} models.Response{data=models.Script}
// @Router /scripts/{id} [put]
func (h *AutomationHandler) UpdateScript(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var req models.CreateScriptRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, models.Response{
			Code:    400,
			Message: "请求参数错误: " + err.Error(),
		})
		return
	}

	var script models.Script
	if err := h.db.First(&script, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "脚本不存在",
		})
		return
	}

	updates := map[string]interface{}{
		"name":        req.Name,
		"description": req.Description,
		"type":        req.Type,
		"content":     req.Content,
		"params":      req.Params,
		"timeout":     req.Timeout,
		"version":     script.Version + 1,
	}

	if err := h.db.Model(&script).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "更新失败",
		})
		return
	}

	h.db.First(&script, id)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "更新成功",
		Data:    script,
	})
}

// DeleteScript 删除脚本
// @Summary 删除脚本
// @Description 删除指定脚本
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param id path int true "脚本ID"
// @Success 200 {object} models.Response
// @Router /scripts/{id} [delete]
func (h *AutomationHandler) DeleteScript(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	if err := h.db.Delete(&models.Script{}, id).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "删除失败",
		})
		return
	}

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "删除成功",
	})
}

// ExecuteScript 执行脚本
// @Summary 执行脚本
// @Description 在目标服务器上执行脚本
// @Tags 自动化运维
// @Accept json
// @Produce json
// @Security Bearer
// @Param id path int true "脚本ID"
// @Param request body models.ExecuteScriptRequest true "执行请求"
// @Success 200 {object} models.Response{data=models.TaskExecution}
// @Router /scripts/{id}/execute [post]
func (h *AutomationHandler) ExecuteScript(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))

	var script models.Script
	if err := h.db.First(&script, id).Error; err != nil {
		c.JSON(http.StatusNotFound, models.Response{
			Code:    404,
			Message: "脚本不存在",
		})
		return
	}

	// The request body is optional — when omitted we execute locally.
	var req models.ExecuteScriptRequest
	_ = c.ShouldBindJSON(&req)

	now := time.Now()
	execution := models.TaskExecution{
		TaskType:   "script",
		TaskID:     uint(id),
		TaskName:   script.Name,
		Status:     "running",
		TargetType: req.TargetType,
		StartedAt:  &now,
	}
	if err := h.db.Create(&execution).Error; err != nil {
		c.JSON(http.StatusInternalServerError, models.Response{
			Code:    500,
			Message: "创建执行记录失败",
		})
		return
	}

	// Execute locally on the AIOps host.
	output, exitCode, duration := runLocal(script.Type, script.Content, script.Timeout)
	finishedAt := time.Now()
	status := "success"
	if exitCode != 0 {
		status = "failed"
	}

	h.db.Model(&execution).Updates(map[string]interface{}{
		"status":      status,
		"output":      output,
		"duration":    duration,
		"finished_at": finishedAt,
	})
	h.db.Model(&script).UpdateColumn("run_count", script.RunCount+1)

	execution.Output = output
	execution.Status = status
	execution.Duration = duration
	execution.FinishedAt = &finishedAt

	msg := "执行成功"
	if status == "failed" {
		msg = "执行失败"
	}
	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: msg,
		Data:    execution,
	})
}

// ListExecutions 获取任务执行记录列表
// @Summary 获取任务执行记录
// @Description 获取脚本/定时任务的执行历史记录（支持 task_type / task_id 筛选）
// @Tags 自动化运维
// @Produce json
// @Security Bearer
// @Param page query int false "页码"
// @Param page_size query int false "每页数量"
// @Param task_type query string false "任务类型 (cron/script)"
// @Param task_id query string false "任务ID"
// @Success 200 {object} models.Response{data=models.ListResponse}
// @Router /task-executions [get]
func (h *AutomationHandler) ListExecutions(c *gin.Context) {
	var query models.PageQuery
	c.ShouldBindQuery(&query)

	db := h.db.Model(&models.TaskExecution{})
	if taskType := c.Query("task_type"); taskType != "" {
		db = db.Where("task_type = ?", taskType)
	}
	if taskID := c.Query("task_id"); taskID != "" {
		db = db.Where("task_id = ?", taskID)
	}

	var total int64
	db.Count(&total)

	var execs []models.TaskExecution
	db.Order("created_at DESC").Offset(query.GetOffset()).Limit(query.GetLimit()).Find(&execs)

	c.JSON(http.StatusOK, models.Response{
		Code:    200,
		Message: "success",
		Data: models.ListResponse{
			List:  execs,
			Total: total,
		},
	})
}