package health

import (
	"context"
	"net/http"
	"time"

	"mengstack/internal/app/version"

	"github.com/gin-gonic/gin"
	"github.com/redis/go-redis/v9"
	"go.uber.org/zap"
	"gorm.io/gorm"
)

type Handler struct {
	db  *gorm.DB
	rdb *redis.Client
	log *zap.Logger
}

func NewHandler(db *gorm.DB, rdb *redis.Client, log *zap.Logger) *Handler {
	return &Handler{db: db, rdb: rdb, log: log}
}

// Handle godoc
// @Summary      健康检查
// @Description  检查 PostgreSQL 和 Redis 连接状态
// @Tags         System
// @Produce      json
// @Success      200  {object}  object{status=string,database=string,redis=string,timestamp=integer,version=string,trace_id=string}
// @Router       /health [get]
func (h *Handler) Handle(c *gin.Context) {
	status := "ok"
	dbStatus := "connected"
	redisStatus := "connected"

	sqlDB, err := h.db.DB()
	if err != nil || sqlDB.Ping() != nil {
		status = "degraded"
		dbStatus = "disconnected"
	}

	ctx, cancel := context.WithTimeout(c.Request.Context(), 2*time.Second)
	defer cancel()
	if h.rdb.Ping(ctx).Err() != nil {
		status = "degraded"
		redisStatus = "disconnected"
	}

	c.JSON(http.StatusOK, gin.H{
		"status":    status,
		"database":  dbStatus,
		"redis":     redisStatus,
		"timestamp": time.Now().Unix(),
		"version":   version.Version,
		"trace_id":  c.GetString("trace_id"),
	})
}

// Version godoc
// @Summary      版本信息
// @Description  返回构建版本、提交哈希、编译时间等
// @Tags         System
// @Produce      json
// @Success      200  {object}  version.Info
// @Router       /api/version [get]
func (h *Handler) Version(c *gin.Context) {
	c.JSON(http.StatusOK, version.Current())
}

// Healthz godoc
// @Summary      存活探针
// @Description  Kubernetes liveness probe，进程存活即返回 200
// @Tags         System
// @Produce      json
// @Success      200  {object}  object{status=string}
// @Router       /healthz [get]
func (h *Handler) Healthz(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{"status": "ok"})
}

// Readyz godoc
// @Summary      就绪探针
// @Description  Kubernetes readiness probe，检查数据库和 Redis 连接
// @Tags         System
// @Produce      json
// @Success      200  {object}  object{status=string,database=string,redis=string}
// @Failure      503  {object}  object{status=string,database=string,redis=string}
// @Router       /readyz [get]
func (h *Handler) Readyz(c *gin.Context) {
	ctx, cancel := context.WithTimeout(c.Request.Context(), 2*time.Second)
	defer cancel()

	dbOK := true
	sqlDB, err := h.db.DB()
	if err != nil || sqlDB.Ping() != nil {
		dbOK = false
	}

	redisOK := true
	if h.rdb.Ping(ctx).Err() != nil {
		redisOK = false
	}

	body := gin.H{
		"database": boolToStatus(dbOK),
		"redis":    boolToStatus(redisOK),
	}

	if !dbOK || !redisOK {
		c.JSON(http.StatusServiceUnavailable, body)
		return
	}
	c.JSON(http.StatusOK, body)
}

func boolToStatus(ok bool) string {
	if ok {
		return "connected"
	}
	return "disconnected"
}