package handler

import (
	"time"

	"github.com/gofiber/fiber/v2"
	"github.com/subconverter-go/internal/config"
	"github.com/subconverter-go/internal/logging"
)

// HealthHandler 健康检查处理器
// 提供应用程序健康状态检查功能
type HealthHandler struct {
	logger     *logging.Logger
	configMgr  *config.ConfigManager
	startTime  time.Time
}

// NewHealthHandler 创建新的健康检查处理器
// 返回初始化好的HealthHandler实例
func NewHealthHandler(logger *logging.Logger, configMgr *config.ConfigManager) *HealthHandler {
	return &HealthHandler{
		logger:     logger,
		configMgr:  configMgr,
		startTime:  time.Now(),
	}
}

// HandleHealth 处理健康检查请求
// 返回应用程序的健康状态信息
func (h *HealthHandler) HandleHealth(c *fiber.Ctx) error {
	h.logger.Debug("Health check request received")

	// 获取配置信息
	config := h.configMgr.GetConfig()

	// 计算运行时间
	uptime := time.Since(h.startTime).String()

	// 创建健康状态响应
	health := map[string]interface{}{
		"status":       "healthy",
		"timestamp":    time.Now().Format(time.RFC3339),
		"uptime":       uptime,
		"version":      "1.0.0",
		"service":      "subconverter-go",
		"environment":  "development", // 可以从配置中获取
	}

	// 添加服务器信息
	health["server"] = map[string]interface{}{
		"host": config.Server.Host,
		"port": config.Server.Port,
		"read_timeout":  config.Server.ReadTimeout,
		"write_timeout": config.Server.WriteTimeout,
		"max_request_size": config.Server.MaxRequestSize,
	}

	// 添加配置信息
	health["config"] = map[string]interface{}{
		"default_target": config.Conversion.DefaultTarget,
		"supported_targets": config.Conversion.SupportedTargets,
		"rate_limit": config.Security.RateLimit,
		"cors_origins": config.Security.CorsOrigins,
	}

	// 添加系统信息
	health["system"] = map[string]interface{}{
		"memory_usage": "N/A",  // 可以添加内存使用情况
		"cpu_usage":    "N/A",  // 可以添加CPU使用情况
		"goroutines":   "N/A",  // 可以添加goroutine数量
	}

	// 设置响应头
	c.Set("Cache-Control", "no-cache, no-store, must-revalidate")
	c.Set("Pragma", "no-cache")
	c.Set("Expires", "0")

	return c.JSON(health)
}

// HandleReady 处理就绪检查请求
// 用于Kubernetes等系统的就绪探针
func (h *HealthHandler) HandleReady(c *fiber.Ctx) error {
	h.logger.Debug("Readiness check request received")

	// 检查配置是否已加载
	config := h.configMgr.GetConfig()
	if config == nil {
		h.logger.Warn("Configuration not loaded for readiness check")
		return c.Status(fiber.StatusServiceUnavailable).JSON(map[string]interface{}{
			"status":  "not ready",
			"message": "configuration not loaded",
		})
	}

	// 检查必要的服务是否可用
	// 这里可以添加数据库连接、外部服务连接等检查

	// 创建就绪状态响应
	ready := map[string]interface{}{
		"status":    "ready",
		"timestamp": time.Now().Format(time.RFC3339),
		"service":   "subconverter-go",
		"checks": map[string]interface{}{
			"configuration": "ok",
			"server":        "ok",
			"dependencies":  "ok",
		},
	}

	return c.JSON(ready)
}

// HandleLive 处理存活检查请求
// 用于Kubernetes等系统的存活探针
func (h *HealthHandler) HandleLive(c *fiber.Ctx) error {
	h.logger.Debug("Liveness check request received")

	// 简单的存活检查，如果应用程序能响应就认为存活
	live := map[string]interface{}{
		"status":    "alive",
		"timestamp": time.Now().Format(time.RFC3339),
		"service":   "subconverter-go",
	}

	return c.JSON(live)
}

// HandleMetrics 处理指标请求
// 返回应用程序的运行时指标
func (h *HealthHandler) HandleMetrics(c *fiber.Ctx) error {
	h.logger.Debug("Metrics request received")

	// 获取配置信息
	config := h.configMgr.GetConfig()

	// 计算运行时间
	uptime := time.Since(h.startTime)

	// 创建指标响应
	metrics := map[string]interface{}{
		"timestamp": time.Now().Format(time.RFC3339),
		"uptime_ms": uptime.Milliseconds(),
		"service":   "subconverter-go",
		"version":   "1.0.0",
	}

	// 添加服务器指标
	metrics["server"] = map[string]interface{}{
		"host": config.Server.Host,
		"port": config.Server.Port,
		"config": map[string]interface{}{
			"read_timeout":  config.Server.ReadTimeout,
			"write_timeout": config.Server.WriteTimeout,
			"max_request_size": config.Server.MaxRequestSize,
		},
	}

	// 添加转换相关指标
	metrics["conversion"] = map[string]interface{}{
		"default_target": config.Conversion.DefaultTarget,
		"supported_targets": config.Conversion.SupportedTargets,
		"default_emoji": config.Conversion.DefaultEmoji,
		"default_udp": config.Conversion.DefaultUDP,
		"max_nodes": config.Conversion.MaxNodes,
		"cache_timeout": config.Conversion.CacheTimeout,
	}

	// 添加安全相关指标
	metrics["security"] = map[string]interface{}{
		"rate_limit": config.Security.RateLimit,
		"timeout": config.Security.Timeout,
		"cors_origins_count": len(config.Security.CorsOrigins),
		"access_tokens_count": len(config.Security.AccessTokens),
	}

	// 添加日志相关指标
	metrics["logging"] = map[string]interface{}{
		"level": config.Logging.Level,
		"format": config.Logging.Format,
		"output": config.Logging.Output,
	}

	return c.JSON(metrics)
}

// HandlePing 处理ping请求
// 用于网络连通性测试
func (h *HealthHandler) HandlePing(c *fiber.Ctx) error {
	h.logger.Debug("Ping request received")

	// 简单的ping响应
	ping := map[string]interface{}{
		"message":   "pong",
		"timestamp": time.Now().Format(time.RFC3339),
		"service":   "subconverter-go",
		"version":   "1.0.0",
	}

	return c.JSON(ping)
}

// GetUptime 获取应用程序运行时间
func (h *HealthHandler) GetUptime() time.Duration {
	return time.Since(h.startTime)
}

// GetStartTime 获取应用程序启动时间
func (h *HealthHandler) GetStartTime() time.Time {
	return h.startTime
}