package stock

import (
	"fmt"
	"log"
	"sync"
	"time"
	"context"
	"net/http"

	"github.com/gofiber/fiber/v2"
	"github.com/go-playground/validator/v10"

	helpers "tebakaja_lb_proxy/proxy/helpers"
)



// StockPredictionHandler   godoc
// @Summary                 Stock Prediction
// @Description             Stock Prediction
// @Tags                    Stock
// @Accept                  json
// @Produce                 json
// @Param                   requestBody body PredictionRequest true "Request Body"
// @Success                 200  {object} PredictionResponse
// @Router                  /stock/prediction [post]
func StockPredictionHandler(service StockService) fiber.Handler {
	return func(c *fiber.Ctx) error {
		ctx, cancel := context.WithTimeout(c.Context(), 120 * time.Second)
		defer cancel()

		ch := make(chan ApiResponse, 1)
		var wg sync.WaitGroup
		wg.Add(1)

		go func() {
			defer wg.Done()

			var predictionReq PredictionRequest
			if err := c.BodyParser(&predictionReq); err != nil {
				log.Printf("[%s] Failed to parse request body: %v",
					time.Now().Format("2006-01-02 15:04:05"), err)

				ch <- ApiResponse{
					Message:    fmt.Sprintf("Failed to parse request body: %v", err),
					StatusCode: http.StatusBadRequest,
				}
				return
			}

			if err := helpers.ValidateStruct(predictionReq); err != nil {
        errors := err.(validator.ValidationErrors)
				
				ch <- ApiResponse{
					Message:    fmt.Sprintf("%v", errors),
					StatusCode: http.StatusBadRequest,
				}
        return
    	}

			apiResponse, err := service.StockPredictionService(ctx, predictionReq)
			if err != nil {
				log.Printf("[%s] %v", time.Now().Format("2006-01-02 15:04:05"), err)
				ch <- apiResponse
				return
			}

			ch <- apiResponse
		}()

		go func() {
			wg.Wait()
			close(ch)
		}()

		select {
			case apiResponse, ok := <-ch:
				if !ok {
					return c.Status(http.StatusInternalServerError).JSON(fiber.Map{
						"error": "Failed to get a response from the server",
					})
				}
				return c.Status(apiResponse.StatusCode).JSON(apiResponse)

			case <-ctx.Done():
				log.Printf("[%s] Timeout: %v", time.Now().Format("2006-01-02 15:04:05"), ctx.Err())
				return c.Status(http.StatusRequestTimeout).JSON(fiber.Map{
					"error": "Request timeout",
				})
		}
	}
}