package controllers

import (
	"context"
	"errors"
	"net/http"
	"strconv"
	"strings"
	"time"

	"lokistack/dto"
	"lokistack/models"
	"lokistack/services"
	"lokistack/utils"

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

func (ctrl *LogsController) Context(c *gin.Context) {
	var req dto.LogContextRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	src := services.GetLogSource(req.SourceID)
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	ts, err := strconv.ParseInt(req.TimestampNs, 10, 64)
	if err != nil || ts < 1 {
		utils.BadRequest(c, "时间戳无效")
		return
	}
	selector, err := services.ContextLogSelector(req.Labels)
	if err != nil {
		utils.BadRequest(c, err.Error())
		return
	}
	query, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", selector)
	if err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	span := int64(5 * time.Minute)
	before, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts-span, ts-1, 5, "backward", "")
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	after, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts+1, ts+span, 5, "forward", "")
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	utils.Success(c, gin.H{"before": before.Entries, "after": after.Entries})
}

// LogsController 日志查询代理 + 数据源管理
type LogsController struct{}

func NewLogsController() *LogsController {
	return &LogsController{}
}

// ==================== 数据源 ====================

func (ctrl *LogsController) ListSources(c *gin.Context) {
	if c.GetString("role") == "admin" {
		services.EnsureLogSourcesForRunningDeployments()
	}
	list := services.ListVisibleLogSources(c.GetUint("userId"), c.GetString("role") == "admin")
	utils.Success(c, utils.PageData{List: list, Total: int64(len(list)), Page: 1, PageSize: 100})
}

func (ctrl *LogsController) CreateSource(c *gin.Context) {
	var req dto.LogSourceRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	if req.Name == "" || req.TargetType == "" {
		utils.BadRequest(c, "名称与类型必填")
		return
	}
	if err := services.ValidateSourceAccess(req.Access); err != nil {
		utils.BadRequest(c, err.Error())
		return
	}
	src := &models.LogSource{
		Name: req.Name, TargetType: req.TargetType,
		Namespace: req.Namespace, Service: req.Service, Port: req.Port,
		URL: req.URL, AuthType: req.AuthType, BasicUser: req.BasicUser,
		BasicPass: req.BasicPass, BearerToken: req.BearerToken, Headers: req.Headers, SkipTLSVerify: req.SkipTLSVerify, IsDefault: req.IsDefault, Access: req.Access,
	}
	if req.TargetType == "cluster-svc" {
		if req.ClusterID > 0 {
			id := req.ClusterID
			src.ClusterID = &id
		} else {
			utils.BadRequest(c, "cluster-svc 类型必须选择集群")
			return
		}
	}
	created, err := services.CreateLogSource(src)
	if err != nil {
		utils.Error(c, 400, err.Error())
		return
	}
	utils.Success(c, created.Sanitized())
}

func (ctrl *LogsController) UpdateSource(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		utils.BadRequest(c, "ID 无效")
		return
	}
	var updates map[string]interface{}
	if !utils.BindAndValidate(c, &updates) {
		return
	}
	if src := services.GetLogSource(uint(id)); src != nil && src.Managed && updates["isDefault"] == nil {
		utils.BadRequest(c, "平台部署的数据源由系统管理,不可编辑")
		return
	}
	if err := services.UpdateLogSource(uint(id), updates); err != nil {
		utils.Error(c, 400, err.Error())
		return
	}
	utils.Success(c, gin.H{"message": "updated"})
}

func (ctrl *LogsController) DeleteSource(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		utils.BadRequest(c, "ID 无效")
		return
	}
	if src := services.GetLogSource(uint(id)); src != nil && src.Managed {
		utils.BadRequest(c, "平台部署的数据源随部署管理,请先删除对应部署")
		return
	}
	if err := services.DeleteLogSource(uint(id)); err != nil {
		utils.Error(c, 400, err.Error())
		return
	}
	utils.Success(c, gin.H{"message": "deleted"})
}

// TestSource 数据源连通性测试(按 id 或表单参数)
func (ctrl *LogsController) TestSource(c *gin.Context) {
	var req dto.LogSourceRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	var src *models.LogSource
	if req.ID > 0 {
		src = services.GetLogSource(req.ID)
		if src == nil {
			utils.NotFound(c, "数据源不存在")
			return
		}
	} else {
		src = &models.LogSource{
			TargetType: req.TargetType, Namespace: req.Namespace, Service: req.Service,
			Port: req.Port, URL: req.URL, AuthType: req.AuthType,
			BasicUser: req.BasicUser, BasicPass: req.BasicPass, BearerToken: req.BearerToken, Headers: req.Headers, SkipTLSVerify: req.SkipTLSVerify,
		}
		if req.TargetType == "cluster-svc" && req.ClusterID > 0 {
			id := req.ClusterID
			src.ClusterID = &id
		}
	}
	utils.Success(c, services.TestLogSource(c.Request.Context(), src))
}

// ==================== 查询代理 ====================

func (ctrl *LogsController) Query(c *gin.Context) {
	var req dto.LogQueryRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	src := services.GetLogSource(req.SourceID)
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	query, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", req.Query)
	if err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	result, err := services.QueryLokiLogs(c.Request.Context(), src, query,
		req.Start, req.End, req.Limit, req.Direction, req.Cursor)
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	utils.Success(c, result)
}

func (ctrl *LogsController) Labels(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Query("sourceId"), 10, 64)
	src := services.GetLogSource(uint(id))
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	if _, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", "{}"); err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	start, _ := strconv.ParseInt(c.Query("start"), 10, 64)
	end, _ := strconv.ParseInt(c.Query("end"), 10, 64)
	labels, err := services.LokiLabels(c.Request.Context(), src, start, end)
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	utils.Success(c, labels)
}

func (ctrl *LogsController) LabelValues(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Query("sourceId"), 10, 64)
	src := services.GetLogSource(uint(id))
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	start, _ := strconv.ParseInt(c.Query("start"), 10, 64)
	end, _ := strconv.ParseInt(c.Query("end"), 10, 64)
	requestedQuery := c.Query("query")
	if strings.TrimSpace(requestedQuery) == "" {
		requestedQuery = "{}"
	}
	query, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", requestedQuery)
	if err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	values, err := services.LokiLabelValues(c.Request.Context(), src,
		c.Param("name"), query, start, end)
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	utils.Success(c, values)
}

// MyScope 返回当前登录用户在某数据源上的授权范围。
//
// 快捷 LogQL 用它做两件事：
//  1. 把授权策略里配置的 namespace 作为默认选中值（管理员配了 default/astralx 后开箱即用）
//  2. 把该值合并进 namespace 候选列表 —— 否则像 default 这种「策略里有、Loki 里没日志」
//     的命名空间不会出现在下拉里，用户会以为策略没生效
func (ctrl *LogsController) MyScope(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Query("sourceId"), 10, 64)
	src := services.GetLogSource(uint(id))
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	if c.GetString("role") == "admin" {
		// 管理员的查询范围不受策略限制（unrestricted=true），
		// 但仍返回策略里的 labels 作为快捷 LogQL 的默认选中值——
		// 否则管理员在小黑框里看到的下拉永远没有策略配的那个 namespace，
		// 会误以为「默认策略没生效」。
		labels := services.UserAccessLabels(src, c.GetUint("userId"))
		if labels == nil {
			labels = map[string]string{}
		}
		utils.Success(c, gin.H{"labels": labels, "unrestricted": true})
		return
	}
	labels := services.UserAccessLabels(src, c.GetUint("userId"))
	if labels == nil {
		utils.Forbidden(c, "无权查询此数据源")
		return
	}
	utils.Success(c, gin.H{"labels": labels, "unrestricted": len(labels) == 0})
}

// Health Loki /ready 探活(查询页状态点)
func (ctrl *LogsController) Health(c *gin.Context) {
	id, _ := strconv.ParseUint(c.Query("sourceId"), 10, 64)
	src := services.GetLogSource(uint(id))
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	if _, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", "{}"); err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	ctx, cancel := context.WithTimeout(c.Request.Context(), 15*time.Second)
	defer cancel()
	utils.Success(c, gin.H{"ready": services.LokiReady(ctx, src)})
}

func (ctrl *LogsController) Histogram(c *gin.Context) {
	var req dto.LogQueryRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	src := services.GetLogSource(req.SourceID)
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	query, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", req.Query)
	if err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	buckets, err := services.LokiHistogram(c.Request.Context(), src, query, req.Start, req.End)
	if err != nil {
		switch {
		case errors.Is(err, services.ErrTooManyQueries):
			// 429：并发重查询超限，让前端提示"稍后重试"，而不是当成服务故障
			utils.Error(c, http.StatusTooManyRequests, err.Error())
		case strings.Contains(err.Error(), "统计范围过大"):
			utils.Error(c, http.StatusBadRequest, err.Error())
		default:
			utils.Error(c, 502, err.Error())
		}
		return
	}
	utils.Success(c, buckets)
}

// Metrics 日志分析指标查询(仅 admin,路由层 AdminAuth 拦截)
func (ctrl *LogsController) Metrics(c *gin.Context) {
	var req dto.LogMetricQueryRequest
	if !utils.BindAndValidate(c, &req) {
		return
	}
	src := services.GetLogSource(req.SourceID)
	if src == nil {
		utils.BadRequest(c, "数据源不存在")
		return
	}
	query, err := services.AuthorizedLogQuery(src, c.GetUint("userId"), c.GetString("role") == "admin", req.Query)
	if err != nil {
		utils.Forbidden(c, err.Error())
		return
	}
	series, err := services.LokiMetrics(c.Request.Context(), src, query, req.Start, req.End)
	if err != nil {
		utils.Error(c, 502, err.Error())
		return
	}
	utils.Success(c, series)
}