package api

import (
	"net/http"

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

// Router API路由注册
type Router struct {
	handler Handler
}

// NewRouter 创建路由
func NewRouter(handler Handler) *Router {
	return &Router{handler: handler}
}

// Register 注册所有路由
func (r *Router) Register(engine *gin.Engine) {
	// 公开接口（无需认证）
	public := engine.Group("/v1")
	{
		public.GET("/admin/health", r.healthCheck)
	}

	// 需要认证的接口
	api := engine.Group("/v1")
	api.Use(r.authMiddleware())
	{
		// 股票接口
		stock := api.Group("/stock")
		{
			stock.GET("/klines/:symbol", r.queryStockKLines)
			stock.GET("/symbols", r.listStockSymbols)
			stock.POST("/klines/batch", r.batchQueryStockKLines)
			stock.GET("/trading-dates", r.getStockTradingDates)
		}

		// 期货接口
		futures := api.Group("/futures")
		{
			futures.GET("/klines/:symbol", r.queryFuturesKLines)
			futures.GET("/symbols", r.listFuturesSymbols)
			futures.POST("/klines/batch", r.batchQueryFuturesKLines)
			futures.GET("/continuous/:underlying", r.queryContinuousKLines)
			futures.GET("/trading-dates", r.getFuturesTradingDates)
			futures.GET("/contracts", r.getFuturesContracts)
		}

		// 管理接口
		admin := api.Group("/admin")
		{
			admin.GET("/source/status", r.getDataSourceStatus)
			admin.POST("/source/switch", r.switchDataSource)
			admin.POST("/backfill", r.backfillData)
		}
	}
}

// authMiddleware API认证中间件
func (r *Router) authMiddleware() gin.HandlerFunc {
	return func(c *gin.Context) {
		apiKey := c.GetHeader("X-API-Key")
		if apiKey == "" {
			c.JSON(http.StatusUnauthorized, ErrorResponse{
				Code:    401,
				Message: "缺少API Key",
			})
			c.Abort()
			return
		}
		
		// TODO: 验证API Key有效性
		// 可以将用户信息存入context
		c.Set("api_key", apiKey)
		c.Next()
	}
}

// ============================================
// 股票接口实现
// ============================================

func (r *Router) queryStockKLines(c *gin.Context) {
	var req KLineQueryRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	req.Symbol = c.Param("symbol")

	resp, err := r.handler.QueryKLines(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) listStockSymbols(c *gin.Context) {
	var req SymbolListRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.ListSymbols(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) batchQueryStockKLines(c *gin.Context) {
	var req BatchKLineRequest
	if err := c.ShouldBindBodyWith(&req, binding.JSON); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.BatchQueryKLines(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

// ============================================
// 期货接口实现
// ============================================

func (r *Router) queryFuturesKLines(c *gin.Context) {
	var req KLineQueryRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	req.Symbol = c.Param("symbol")

	resp, err := r.handler.QueryKLines(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) listFuturesSymbols(c *gin.Context) {
	var req SymbolListRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.ListSymbols(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) batchQueryFuturesKLines(c *gin.Context) {
	var req BatchKLineRequest
	if err := c.ShouldBindBodyWith(&req, binding.JSON); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.BatchQueryKLines(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) queryContinuousKLines(c *gin.Context) {
	underlying := c.Param("underlying")
	
	var req KLineQueryRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.QueryContinuousKLines(c.Request.Context(), underlying, &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

// ============================================
// 管理接口实现
// ============================================

func (r *Router) getDataSourceStatus(c *gin.Context) {
	resp, err := r.handler.GetDataSourceStatus(c.Request.Context())
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) switchDataSource(c *gin.Context) {
	var req SourceSwitchRequest
	if err := c.ShouldBindBodyWith(&req, binding.JSON); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.SwitchDataSource(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusUnprocessableEntity, ErrorResponse{
			Code:    422,
			Message: "数据源切换失败",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) backfillData(c *gin.Context) {
	var req BackfillRequest
	if err := c.ShouldBindBodyWith(&req, binding.JSON); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.BackfillData(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "补录任务失败",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusAccepted, resp)
}

func (r *Router) healthCheck(c *gin.Context) {
	resp, err := r.handler.HealthCheck(c.Request.Context())
	if err != nil {
		c.JSON(http.StatusServiceUnavailable, ErrorResponse{
			Code:    503,
			Message: "服务不可用",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

// ============================================
// 新增接口：交易日历和期货合约
// ============================================

func (r *Router) getStockTradingDates(c *gin.Context) {
	var req TradingDatesRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.GetTradingDates(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) getFuturesTradingDates(c *gin.Context) {
	var req TradingDatesRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.GetTradingDates(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}

func (r *Router) getFuturesContracts(c *gin.Context) {
	var req FuturesContractsRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		c.JSON(http.StatusBadRequest, ErrorResponse{
			Code:    400,
			Message: "参数错误",
			Detail:  err.Error(),
		})
		return
	}

	resp, err := r.handler.GetContractsByUnderlying(c.Request.Context(), &req)
	if err != nil {
		c.JSON(http.StatusInternalServerError, ErrorResponse{
			Code:    500,
			Message: "服务器内部错误",
			Detail:  err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, resp)
}