package handler

import (
	"errors"
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	"dating-app/internal/dto"
	"dating-app/internal/models"
	"dating-app/internal/service"
	"dating-app/internal/utils"
)

type DiscoveryHandler struct {
	discoveryService *service.DiscoveryService
}

func NewDiscoveryHandler(discoveryService *service.DiscoveryService) *DiscoveryHandler {
	return &DiscoveryHandler{discoveryService: discoveryService}
}

// Feed GET /discover?max_distance_km=&min_age=&max_age=
func (h *DiscoveryHandler) Feed(c *gin.Context) {
	user, ok := currentUser(c)
	if !ok {
		return
	}

	var maxDistance *float64
	if raw := c.Query("max_distance_km"); raw != "" {
		if v, err := strconv.ParseFloat(raw, 64); err == nil {
			maxDistance = &v
		}
	}
	minAge, _ := strconv.Atoi(c.Query("min_age"))
	maxAge, _ := strconv.Atoi(c.Query("max_age"))

	candidates, err := h.discoveryService.GetFeed(user, maxDistance, minAge, maxAge)
	if err != nil {
		h.handleError(c, err)
		return
	}
	utils.Success(c, http.StatusOK, "", candidates)
}

// CandidateDetail GET /discover/:id
func (h *DiscoveryHandler) CandidateDetail(c *gin.Context) {
	user, ok := currentUser(c)
	if !ok {
		return
	}
	targetID, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		utils.Fail(c, http.StatusBadRequest, "شناسه نامعتبر است", nil)
		return
	}
	detail, err := h.discoveryService.GetCandidateDetail(user, uint(targetID))
	if err != nil {
		utils.Fail(c, http.StatusNotFound, "پروفایل یافت نشد", nil)
		return
	}
	utils.Success(c, http.StatusOK, "", detail)
}

// Swipe POST /discover/:id/swipe   body: {action: "like"|"pass"|"superlike"}
func (h *DiscoveryHandler) Swipe(c *gin.Context) {
	user, ok := currentUser(c)
	if !ok {
		return
	}
	targetID, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		utils.Fail(c, http.StatusBadRequest, "شناسه نامعتبر است", nil)
		return
	}
	var req dto.SwipeRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		utils.Fail(c, http.StatusBadRequest, "ورودی نامعتبر است", err.Error())
		return
	}

	result, err := h.discoveryService.Swipe(user, uint(targetID), models.SwipeAction(req.Action))
	if err != nil {
		h.handleError(c, err)
		return
	}
	utils.Success(c, http.StatusOK, "", result)
}

func (h *DiscoveryHandler) handleError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, service.ErrGenderNotSet):
		utils.Fail(c, http.StatusConflict, err.Error(), nil)
	case errors.Is(err, service.ErrCannotSwipeSelf), errors.Is(err, service.ErrAlreadySwiped):
		utils.Fail(c, http.StatusBadRequest, err.Error(), nil)
	default:
		utils.Fail(c, http.StatusInternalServerError, "خطای داخلی سرور", nil)
	}
}