package auth

import (
	"database/sql"
	"net/http"
	"net/url"

	"github.com/alexedwards/scs/v2"
	"github.com/google/uuid"

	"github.com/ryanhamamura/games/auth"
	"github.com/ryanhamamura/games/db/repository"
	"github.com/ryanhamamura/games/features/auth/pages"
	appsessions "github.com/ryanhamamura/games/sessions"
)

func HandleLoginPage(sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		// Capture return_url so we can redirect back after login
		if returnURL := r.URL.Query().Get("return_url"); returnURL != "" {
			sessions.Put(r.Context(), "return_url", returnURL)
		}

		errorMsg := r.URL.Query().Get("error")
		if err := pages.LoginPage(errorMsg).Render(r.Context(), w); err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
	}
}

func HandleRegisterPage() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		errorMsg := r.URL.Query().Get("error")
		if err := pages.RegisterPage(errorMsg).Render(r.Context(), w); err != nil {
			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		}
	}
}

func HandleLogin(queries *repository.Queries, sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		username := r.FormValue("username")
		password := r.FormValue("password")

		user, err := queries.GetUserByUsername(r.Context(), username)
		if err == sql.ErrNoRows {
			http.Redirect(w, r, "/login?error="+url.QueryEscape("Invalid username or password"), http.StatusSeeOther)
			return
		}
		if err != nil {
			http.Redirect(w, r, "/login?error="+url.QueryEscape("An error occurred"), http.StatusSeeOther)
			return
		}
		if !auth.CheckPassword(password, user.PasswordHash) {
			http.Redirect(w, r, "/login?error="+url.QueryEscape("Invalid username or password"), http.StatusSeeOther)
			return
		}

		sessions.RenewToken(r.Context()) //nolint:errcheck
		sessions.Put(r.Context(), appsessions.KeyUserID, user.ID)
		sessions.Put(r.Context(), "username", user.Username)
		sessions.Put(r.Context(), appsessions.KeyNickname, user.Username)

		redirectURL := "/"
		if returnURL := sessions.GetString(r.Context(), "return_url"); returnURL != "" {
			sessions.Put(r.Context(), "return_url", "")
			redirectURL = returnURL
		}

		http.Redirect(w, r, redirectURL, http.StatusSeeOther)
	}
}

func HandleRegister(queries *repository.Queries, sessions *scs.SessionManager) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		username := r.FormValue("username")
		password := r.FormValue("password")
		confirm := r.FormValue("confirm")

		if err := auth.ValidateUsername(username); err != nil {
			http.Redirect(w, r, "/register?error="+url.QueryEscape(err.Error()), http.StatusSeeOther)
			return
		}
		if err := auth.ValidatePassword(password); err != nil {
			http.Redirect(w, r, "/register?error="+url.QueryEscape(err.Error()), http.StatusSeeOther)
			return
		}
		if password != confirm {
			http.Redirect(w, r, "/register?error="+url.QueryEscape("Passwords do not match"), http.StatusSeeOther)
			return
		}

		hash, err := auth.HashPassword(password)
		if err != nil {
			http.Redirect(w, r, "/register?error="+url.QueryEscape("An error occurred"), http.StatusSeeOther)
			return
		}

		user, err := queries.CreateUser(r.Context(), repository.CreateUserParams{
			ID:           uuid.New().String(),
			Username:     username,
			PasswordHash: hash,
		})
		if err != nil {
			http.Redirect(w, r, "/register?error="+url.QueryEscape("Username already taken"), http.StatusSeeOther)
			return
		}

		sessions.RenewToken(r.Context()) //nolint:errcheck
		sessions.Put(r.Context(), appsessions.KeyUserID, user.ID)
		sessions.Put(r.Context(), "username", user.Username)
		sessions.Put(r.Context(), appsessions.KeyNickname, user.Username)

		redirectURL := "/"
		if returnURL := sessions.GetString(r.Context(), "return_url"); returnURL != "" {
			sessions.Put(r.Context(), "return_url", "")
			redirectURL = returnURL
		}

		http.Redirect(w, r, redirectURL, http.StatusSeeOther)
	}
}