package repository

import (
	"context"
	"errors"
	"fmt"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
	"github.com/panelhosting/panel/internal/httputil"
	"github.com/panelhosting/panel/internal/models"
)

var ErrUserNotFound = errors.New("user not found")

func (r *UserRepository) GetByUsername(ctx context.Context, username string) (*models.User, error) {
	const q = `
		SELECT id, uuid, email, username, password_hash, role, status, locale, timezone, last_login_at, created_at, updated_at
		FROM users WHERE LOWER(username) = LOWER($1)
	`
	var u models.User
	err := r.pool.QueryRow(ctx, q, username).Scan(
		&u.ID, &u.UUID, &u.Email, &u.Username, &u.PasswordHash, &u.Role, &u.Status,
		&u.Locale, &u.Timezone, &u.LastLoginAt, &u.CreatedAt, &u.UpdatedAt,
	)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, ErrUserNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("get user by username: %w", err)
	}
	return &u, nil
}

func (r *UserRepository) GetByID(ctx context.Context, id int64) (*models.User, error) {
	const q = `
		SELECT id, uuid, email, username, password_hash, role, status, locale, timezone, last_login_at, created_at, updated_at
		FROM users WHERE id = $1
	`
	var u models.User
	err := r.pool.QueryRow(ctx, q, id).Scan(
		&u.ID, &u.UUID, &u.Email, &u.Username, &u.PasswordHash, &u.Role, &u.Status,
		&u.Locale, &u.Timezone, &u.LastLoginAt, &u.CreatedAt, &u.UpdatedAt,
	)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, ErrUserNotFound
	}
	if err != nil {
		return nil, fmt.Errorf("get user by id: %w", err)
	}
	return &u, nil
}

func (r *UserRepository) UpdateLastLogin(ctx context.Context, id int64) error {
	_, err := r.pool.Exec(ctx, `UPDATE users SET last_login_at = now() WHERE id = $1`, id)
	return err
}

type SessionRepository struct {
	pool *pgxpool.Pool
}

func NewSessionRepository(pool *pgxpool.Pool) *SessionRepository {
	return &SessionRepository{pool: pool}
}

func (r *SessionRepository) Create(ctx context.Context, userID int64, tokenHash string, ip, userAgent string, expiresAt time.Time) error {
	var ipArg any
	if normalized, ok := httputil.ValidIP(ip); ok {
		ipArg = normalized
	}

	const q = `
		INSERT INTO sessions (user_id, token_hash, ip_address, user_agent, expires_at)
		VALUES ($1, $2, $3, NULLIF($4, ''), $5)
	`
	_, err := r.pool.Exec(ctx, q, userID, tokenHash, ipArg, userAgent, expiresAt)
	if err != nil {
		return fmt.Errorf("create session: %w", err)
	}
	return nil
}

func (r *SessionRepository) GetUserIDByToken(ctx context.Context, tokenHash string) (int64, error) {
	const q = `
		SELECT user_id FROM sessions
		WHERE token_hash = $1 AND expires_at > now()
	`
	var userID int64
	err := r.pool.QueryRow(ctx, q, tokenHash).Scan(&userID)
	if errors.Is(err, pgx.ErrNoRows) {
		return 0, ErrUserNotFound
	}
	if err != nil {
		return 0, fmt.Errorf("get session: %w", err)
	}
	return userID, nil
}

func (r *SessionRepository) DeleteByToken(ctx context.Context, tokenHash string) error {
	_, err := r.pool.Exec(ctx, `DELETE FROM sessions WHERE token_hash = $1`, tokenHash)
	return err
}