package auth

import (
	"encoding/json"
	"errors"
	"net/http"
	"strings"

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

type Handler struct {
	service *Service
}

func NewHandler(service *Service) *Handler {
	return &Handler{service: service}
}

func (h *Handler) RegisterRoutes(router gin.IRouter) {
	router.POST("/api/auth/register", h.Register)
	router.POST("/api/auth/login", h.Login)
	router.POST("/api/auth/logout", h.Logout)
	router.GET("/api/auth/me", h.Me)
}

func (h *Handler) RegisterProtectedRoutes(router gin.IRouter, require gin.HandlerFunc) {
	router.PATCH("/api/auth/me", require, h.UpdateMe)
	router.POST("/api/auth/password", require, h.ChangePassword)
}

type credentialsRequest struct {
	Email    string `json:"email"`
	Password string `json:"password"`
	Name     string `json:"name"`
}

type profileRequest struct {
	Email        string `json:"email"`
	Name         string `json:"name"`
	StudioName   string `json:"studioName"`
	Tagline      string `json:"tagline"`
	WebsiteURL   string `json:"websiteUrl"`
	InstagramURL string `json:"instagramUrl"`
}

type passwordRequest struct {
	CurrentPassword string `json:"currentPassword"`
	NewPassword     string `json:"newPassword"`
}

// Register godoc
// @Summary Register a photographer account
// @Tags authentication
// @Accept json
// @Produce json
// @Param request body credentialsRequest true "Account details"
// @Success 201 {object} map[string]interface{}
// @Failure 400 {object} map[string]string
// @Failure 409 {object} map[string]string
// @Router /api/auth/register [post]
func (h *Handler) Register(c *gin.Context) {
	var request credentialsRequest
	if !decodeJSON(c, &request) {
		return
	}
	user, err := h.service.Register(c.Request.Context(), request.Email, request.Password, request.Name)
	if err != nil {
		if errors.Is(err, ErrEmailTaken) {
			writeJSON(c, http.StatusConflict, map[string]string{"error": "email is already registered"})
			return
		}
		writeJSON(c, http.StatusBadRequest, map[string]string{"error": err.Error()})
		return
	}
	h.service.SetSession(c, user)
	writeJSON(c, http.StatusCreated, map[string]User{"user": user})
}

// Login godoc
// @Summary Sign in a photographer
// @Tags authentication
// @Accept json
// @Produce json
// @Param request body credentialsRequest true "Account credentials"
// @Success 200 {object} map[string]interface{}
// @Failure 400 {object} map[string]string
// @Failure 401 {object} map[string]string
// @Router /api/auth/login [post]
func (h *Handler) Login(c *gin.Context) {
	var request credentialsRequest
	if !decodeJSON(c, &request) {
		return
	}
	user, err := h.service.Login(c.Request.Context(), request.Email, request.Password)
	if err != nil {
		if errors.Is(err, ErrInvalidCredentials) {
			writeJSON(c, http.StatusUnauthorized, map[string]string{"error": "invalid email or password"})
			return
		}
		writeJSON(c, http.StatusInternalServerError, map[string]string{"error": "could not sign in"})
		return
	}
	h.service.SetSession(c, user)
	writeJSON(c, http.StatusOK, map[string]User{"user": user})
}

// Logout godoc
// @Summary Sign out the current photographer
// @Tags authentication
// @Produce json
// @Success 200 {object} map[string]string
// @Router /api/auth/logout [post]
func (h *Handler) Logout(c *gin.Context) {
	h.service.ClearSession(c)
	writeJSON(c, http.StatusOK, map[string]string{"status": "ok"})
}

// Me godoc
// @Summary Get the current photographer
// @Tags authentication
// @Produce json
// @Security studioSession
// @Success 200 {object} map[string]interface{}
// @Failure 401 {object} map[string]string
// @Router /api/auth/me [get]
func (h *Handler) Me(c *gin.Context) {
	user, err := h.service.UserFromRequest(c.Request.Context(), c.Request)
	if err != nil {
		writeJSON(c, http.StatusUnauthorized, map[string]string{"error": "authentication required"})
		return
	}
	writeJSON(c, http.StatusOK, map[string]User{"user": user})
}

// UpdateMe godoc
// @Summary Update the current photographer profile
// @Tags authentication
// @Accept json
// @Produce json
// @Security studioSession
// @Param request body profileRequest true "Profile details"
// @Success 200 {object} map[string]interface{}
// @Failure 400 {object} map[string]string
// @Failure 401 {object} map[string]string
// @Failure 409 {object} map[string]string
// @Router /api/auth/me [patch]
func (h *Handler) UpdateMe(c *gin.Context) {
	user, ok := UserFromContext(c)
	if !ok {
		writeJSON(c, http.StatusUnauthorized, map[string]string{"error": "authentication required"})
		return
	}
	var request profileRequest
	if !decodeJSON(c, &request) {
		return
	}
	updated, err := h.service.UpdateProfile(c.Request.Context(), user.ID, request.Email, request.Name, request.StudioName, request.Tagline, request.WebsiteURL, request.InstagramURL)
	if err != nil {
		if errors.Is(err, ErrEmailTaken) {
			writeJSON(c, http.StatusConflict, map[string]string{"error": "email is already registered"})
			return
		}
		if strings.HasPrefix(err.Error(), "enter ") || strings.HasPrefix(err.Error(), "name ") {
			writeJSON(c, http.StatusBadRequest, map[string]string{"error": err.Error()})
			return
		}
		writeJSON(c, http.StatusInternalServerError, map[string]string{"error": "could not update profile"})
		return
	}
	writeJSON(c, http.StatusOK, map[string]User{"user": updated})
}

// ChangePassword godoc
// @Summary Change the current photographer password
// @Tags authentication
// @Accept json
// @Produce json
// @Security studioSession
// @Param request body passwordRequest true "Password details"
// @Success 200 {object} map[string]string
// @Failure 400 {object} map[string]string
// @Failure 401 {object} map[string]string
// @Router /api/auth/password [post]
func (h *Handler) ChangePassword(c *gin.Context) {
	user, ok := UserFromContext(c)
	if !ok {
		writeJSON(c, http.StatusUnauthorized, map[string]string{"error": "authentication required"})
		return
	}
	var request passwordRequest
	if !decodeJSON(c, &request) {
		return
	}
	if err := h.service.ChangePassword(c.Request.Context(), user.ID, request.CurrentPassword, request.NewPassword); err != nil {
		if errors.Is(err, ErrCurrentPassword) {
			writeJSON(c, http.StatusBadRequest, map[string]string{"error": "current password is incorrect"})
			return
		}
		if strings.HasPrefix(err.Error(), "new password") {
			writeJSON(c, http.StatusBadRequest, map[string]string{"error": err.Error()})
			return
		}
		writeJSON(c, http.StatusInternalServerError, map[string]string{"error": "could not update password"})
		return
	}
	writeJSON(c, http.StatusOK, map[string]string{"status": "ok"})
}

func decodeJSON(c *gin.Context, target any) bool {
	if !strings.HasPrefix(c.GetHeader("Content-Type"), "application/json") {
		writeJSON(c, http.StatusUnsupportedMediaType, map[string]string{"error": "content type must be application/json"})
		return false
	}
	decoder := json.NewDecoder(http.MaxBytesReader(c.Writer, c.Request.Body, 1<<20))
	decoder.DisallowUnknownFields()
	if err := decoder.Decode(target); err != nil {
		writeJSON(c, http.StatusBadRequest, map[string]string{"error": "invalid JSON body"})
		return false
	}
	return true
}

func writeJSON(c *gin.Context, status int, value any) {
	c.JSON(status, value)
}