package api

import (
	"log"
	"net/http"
	"time"

	"git.pengzhan.dev/noteplace-server/internal/auth"
	"git.pengzhan.dev/noteplace-server/internal/models"
	"git.pengzhan.dev/noteplace-server/internal/store"
	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
)

// AuthHandler handles the authentication API endpoints.
type AuthHandler struct {
	Store         *store.Store
	Authenticator *auth.Authenticator
}

// HandleCliLogin provides the user with the URL to start the auth process.
func (h *AuthHandler) HandleCliLogin(c *gin.Context) {
	authURL := h.Authenticator.GetAuthURL()

	response := gin.H{
		"message": `Please open the following URL in your browser to authorize the application.\nAfter authorizing, Google will provide a code. Paste it here to complete the login.\nExample: curl -X POST -d '{\"code\":\"YOUR_CODE_HERE\"}' http://localhost:3001/api/auth/google/cli/callback`,
		"url":     authURL,
	}
	c.JSON(http.StatusOK, response)
}

// HandleCliCallback exchanges the code for a token and creates a session.
func (h *AuthHandler) HandleCliCallback(c *gin.Context) {
	var reqBody struct {
		Code string `json:"code"`
	}
	if err := c.ShouldBindJSON(&reqBody); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Invalid request body"})
		return
	}

	token, err := h.Authenticator.ExchangeCodeForToken(reqBody.Code)
	if err != nil {
		log.Printf("Failed to exchange code for token: %v", err)
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Failed to validate code"})
		return
	}

	userInfo, err := h.Authenticator.GetUserInfo(token)
	if err != nil {
		log.Printf("Failed to get user info: %v", err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to get user info from Google"})
		return
	}

	// --- User and Session Logic ---
	user, found := h.Store.GetUserByGoogleID(userInfo.GoogleID)
	if !found {
		userInfo.ID = "user-" + uuid.New().String()
		userInfo.CreatedAt = time.Now().UTC().Format(time.RFC3339)
		if err := h.Store.CreateUser(userInfo); err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create user"})
			return
		}
		user = userInfo
	}

	// Create a new session and save it to the store
	sessionID := "session-" + uuid.New().String()
	now := time.Now().UTC().Format(time.RFC3339)
	newSession := models.Session{
		ID:        sessionID,
		UserID:    user.ID,
		CreatedAt: now,
		UpdatedAt: now,
	}
	if err := h.Store.CreateSession(newSession); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create session"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Login successful!", "session_token": newSession.ID})
}

// HandleGetUser returns the current user based on the session token.
func (h *AuthHandler) HandleGetUser(c *gin.Context) {
	user := c.MustGet("user").(models.User)
	c.JSON(http.StatusOK, user)
}