package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"strconv"
	"time"

	"gitea.loveuer.com/loveuer/upkg/database/cache"
	"github.com/gin-gonic/gin"
)

type App struct {
	cache cache.Cache
}

func NewApp() (*App, error) {
	// 从环境变量获取配置
	redisAddr := getEnv("REDIS_ADDR", "redis-headless.default.svc.cluster.local:6379")
	redisPassword := getEnv("REDIS_PASSWORD", "")
	reconnect := getEnv("REDIS_RECONNECT", "true") == "true"
	reconnectIntervalStr := getEnv("REDIS_RECONNECT_INTERVAL", "10s")

	reconnectInterval, err := time.ParseDuration(reconnectIntervalStr)
	if err != nil {
		log.Printf("Invalid reconnect interval %s, using default 10s", reconnectIntervalStr)
		reconnectInterval = 10 * time.Second
	}

	var cacheInstance cache.Cache

	if redisAddr != "" {
		// 检查是否是 Headless Service
		if contains(redisAddr, "svc.cluster.local") {
			log.Printf("Using headless service mode: %s", redisAddr)
			cacheInstance, err = cache.NewRedisFromHeadlessService(redisAddr, redisPassword)
			if err != nil {
				return nil, fmt.Errorf("failed to connect to headless redis: %w", err)
			}
		} else {
			// 使用普通连接
			config := cache.NewConfig("redis", redisAddr)
			config.Password = redisPassword
			config.Reconnect = reconnect
			config.ReconnectInterval = reconnectInterval

			cacheInstance, err = cache.Open(config)
			if err != nil {
				return nil, fmt.Errorf("failed to connect to redis: %w", err)
			}
		}
	} else {
		// 使用内存缓存
		log.Println("Using memory cache (no redis addr specified)")
		cacheInstance = cache.NewMemoryCache()
	}

	return &App{cache: cacheInstance}, nil
}

func (a *App) setupRoutes() *gin.Engine {
	r := gin.Default()

	// 健康检查
	r.GET("/health", a.healthCheck)

	// 缓存操作路由
	api := r.Group("/api")
	{
		api.GET("/cache/:key", a.getCache)
		api.POST("/cache/:key", a.setCache)
		api.DELETE("/cache/:key", a.deleteCache)

		// Hash 操作
		api.GET("/hash/:key/:field", a.getHash)
		api.POST("/hash/:key/:field", a.setHash)
		api.GET("/hash/:key", a.getAllHash)

		// 计数器
		api.POST("/counter/:key/inc", a.incrementCounter)
		api.POST("/counter/:key/inc/:value", a.incrementCounterBy)

		// 测试重连功能
		api.POST("/test/reconnect", a.testReconnect)
	}

	return r
}

func (a *App) healthCheck(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{
		"status":    "ok",
		"timestamp": time.Now().Unix(),
		"service":   "redis-cache-demo",
	})
}

func (a *App) getCache(c *gin.Context) {
	key := c.Param("key")

	ctx := context.Background()
	val, err := a.cache.Get(ctx, key)
	if err != nil {
		if err == cache.ErrKeyNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "key not found"})
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"key":   key,
		"value": val,
	})
}

func (a *App) setCache(c *gin.Context) {
	key := c.Param("key")

	var req struct {
		Value     string `json:"value"`
		ExpiresIn int    `json:"expires_in,omitempty"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	ctx := context.Background()
	var err error

	if req.ExpiresIn > 0 {
		err = a.cache.Set(ctx, key, req.Value, time.Duration(req.ExpiresIn)*time.Second)
	} else {
		err = a.cache.Set(ctx, key, req.Value)
	}

	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": "ok",
		"key":     key,
		"value":   req.Value,
	})
}

func (a *App) deleteCache(c *gin.Context) {
	key := c.Param("key")

	ctx := context.Background()
	err := a.cache.Del(ctx, key)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "deleted", "key": key})
}

func (a *App) getHash(c *gin.Context) {
	key := c.Param("key")
	field := c.Param("field")

	ctx := context.Background()
	val, err := a.cache.HGet(ctx, key, field)
	if err != nil {
		if err == cache.ErrKeyNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "key or field not found"})
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"key":   key,
		"field": field,
		"value": val,
	})
}

func (a *App) setHash(c *gin.Context) {
	key := c.Param("key")
	field := c.Param("field")

	var req struct {
		Value string `json:"value"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	ctx := context.Background()
	err := a.cache.HSet(ctx, key, field, req.Value)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"message": "ok",
		"key":     key,
		"field":   field,
		"value":   req.Value,
	})
}

func (a *App) getAllHash(c *gin.Context) {
	key := c.Param("key")

	ctx := context.Background()
	hash, err := a.cache.HGetAll(ctx, key)
	if err != nil {
		if err == cache.ErrKeyNotFound {
			c.JSON(http.StatusNotFound, gin.H{"error": "key not found"})
		} else {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		}
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"key":  key,
		"data": hash,
	})
}

func (a *App) incrementCounter(c *gin.Context) {
	key := c.Param("key")

	ctx := context.Background()
	val, err := a.cache.Inc(ctx, key)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"key":   key,
		"value": val,
	})
}

func (a *App) incrementCounterBy(c *gin.Context) {
	key := c.Param("key")
	valueStr := c.Param("value")

	value, err := strconv.ParseInt(valueStr, 10, 64)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid value"})
		return
	}

	ctx := context.Background()
	val, err := a.cache.IncBy(ctx, key, value)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"key":   key,
		"value": val,
	})
}

func (a *App) testReconnect(c *gin.Context) {
	ctx := context.Background()

	// 测试读写操作
	testKey := fmt.Sprintf("test_reconnect_%d", time.Now().Unix())
	testValue := fmt.Sprintf("value_%d", time.Now().Unix())

	// 写入测试
	err := a.cache.Set(ctx, testKey, testValue)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"error":  "write failed",
			"detail": err.Error(),
		})
		return
	}

	// 读取测试
	val, err := a.cache.Get(ctx, testKey)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"error":  "read failed",
			"detail": err.Error(),
		})
		return
	}

	// 清理
	a.cache.Del(ctx, testKey)

	c.JSON(http.StatusOK, gin.H{
		"message": "reconnect test successful",
		"write":   testValue,
		"read":    val,
		"match":   val == testValue,
	})
}

func (a *App) Close() error {
	return a.cache.Close()
}

func main() {
	app, err := NewApp()
	if err != nil {
		log.Fatalf("Failed to create app: %v", err)
	}
	defer app.Close()

	r := app.setupRoutes()
	port := getEnv("PORT", "8080")

	log.Printf("Starting server on port %s", port)
	log.Printf("Health check: http://localhost:%s/health", port)
	log.Printf("API endpoints:")
	log.Printf("  GET  /api/cache/:key          - Get value")
	log.Printf("  POST /api/cache/:key          - Set value")
	log.Printf("  GET  /api/hash/:key/:field    - Get hash field")
	log.Printf("  POST /api/hash/:key/:field    - Set hash field")
	log.Printf("  POST /api/counter/:key/inc    - Increment counter")
	log.Printf("  POST /api/test/reconnect      - Test reconnection")

	if err := r.Run(":" + port); err != nil {
		log.Fatalf("Server failed: %v", err)
	}
}

func getEnv(key, defaultValue string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return defaultValue
}

func contains(s, substr string) bool {
	return len(s) >= len(substr) &&
		(s == substr ||
			s[len(s)-len(substr):] == substr ||
			(len(s) > len(substr) &&
				(s[:len(substr)+1] == substr+"." ||
					s[len(s)-len(substr)-1:] == "."+substr)))
}