package api

import (
	"errors"
	"net/http"
	"os"
	"strings"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"hightube/internal/db"
	"hightube/internal/model"
	"hightube/internal/utils"
)

type RegisterRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

type LoginRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

type ChangePasswordRequest struct {
	OldPassword string `json:"old_password" binding:"required"`
	NewPassword string `json:"new_password" binding:"required"`
}

func Register(c *gin.Context) {
	var req RegisterRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	req.Username = strings.TrimSpace(req.Username)
	if strings.EqualFold(req.Username, bootstrapAdminUsername()) {
		c.JSON(http.StatusForbidden, gin.H{"error": "This username is reserved"})
		return
	}

	// Check if user exists
	if _, err := db.LoadUserByUsername(req.Username); err == nil {
		c.JSON(http.StatusConflict, gin.H{"error": "Username already exists"})
		return
	} else if !errors.Is(err, gorm.ErrRecordNotFound) {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to validate username"})
		return
	}

	// Hash password
	hashedPassword, err := utils.HashPassword(req.Password)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to hash password"})
		return
	}

	// Create user
	user := model.User{
		Username: req.Username,
		Password: hashedPassword,
		Role:     "user",
		Enabled:  true,
	}
	room := model.Room{
		Title:     user.Username + "'s Live Room",
		StreamKey: utils.GenerateStreamKey(),
		IsActive:  false,
	}
	if err := db.CreateUserAndRoom(&user, &room); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create user"})
		return
	}

	c.JSON(http.StatusCreated, gin.H{"message": "User registered successfully", "user_id": user.ID})
}

func Login(c *gin.Context) {
	var req LoginRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	req.Username = strings.TrimSpace(req.Username)

	user, err := db.LoadUserByUsername(req.Username)
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid username or password"})
		return
	}

	if !utils.CheckPasswordHash(req.Password, user.Password) {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid username or password"})
		return
	}

	if !user.Enabled {
		c.JSON(http.StatusForbidden, gin.H{"error": "Account is disabled"})
		return
	}

	token, err := utils.GenerateToken(user.ID, user.Username, user.Role)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to generate token"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"token":    token,
		"username": user.Username,
		"role":     user.Role,
		"enabled":  user.Enabled,
	})
}

func ChangePassword(c *gin.Context) {
	userID, _ := c.Get("user_id")

	var req ChangePasswordRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	user, err := db.LoadUserByID(userID.(uint))
	if err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "User not found"})
		return
	}

	// Verify old password
	if !utils.CheckPasswordHash(req.OldPassword, user.Password) {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "Invalid old password"})
		return
	}

	// Hash new password
	hashedPassword, err := utils.HashPassword(req.NewPassword)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to hash password"})
		return
	}

	// Update user
	if err := db.UpdateUserPassword(user.ID, hashedPassword); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update password"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "Password updated successfully"})
}

func bootstrapAdminUsername() string {
	adminUsername := strings.TrimSpace(os.Getenv("HIGHTUBE_ADMIN_USER"))
	if adminUsername == "" {
		return "admin"
	}
	return adminUsername
}