package api

import (
	"context"
	"errors"
	"fmt"
	"log/slog"

	"git.dubyatp.xyz/dubyatp/scannerbot/server/db"
	"github.com/jackc/pgx/v5"
)

var ErrUserNotFound = errors.New("db: user not found")
var ErrSessionNotFound = errors.New("db: session not found")

func dbGetUser(id string) (*User, error) {
	query := `SELECT id, name, password FROM users WHERE id = $1`
	var user User
	err := db.Pool.QueryRow(context.Background(), query, id).Scan(&user.ID, &user.Name, &user.Password)
	if errors.Is(err, pgx.ErrNoRows) {
		slog.Debug("db: user not found", "userid", id)
		return nil, ErrUserNotFound
	} else if err != nil {
		slog.Error("db: failed to query user", "error", err)
		return nil, fmt.Errorf("failed to query user")
	}

	slog.Debug("db: user found", "userid", user.ID, "username", user.Name)
	return &user, nil
}

func dbGetUserByName(username string) (*User, error) {
	query := `SELECT id, name, password FROM users WHERE name = $1`
	var user User
	err := db.Pool.QueryRow(context.Background(), query, username).Scan(&user.ID, &user.Name, &user.Password)
	if errors.Is(err, pgx.ErrNoRows) {
		slog.Debug("db: user not found", "username", username)
		return nil, ErrUserNotFound
	} else if err != nil {
		slog.Error("db: failed to query user", "error", err)
		return nil, fmt.Errorf("failed to query user")
	}

	slog.Debug("db: user found", "userid", user.ID, "username", user.Name)
	return &user, nil
}

func dbGetAllUsers() ([]*User, error) {
	query := `SELECT id, name, password FROM users`
	rows, err := db.Pool.Query(context.Background(), query)
	if err != nil {
		slog.Error("db: failed to query users", "error", err)
		return nil, fmt.Errorf("failed to query users")
	}
	defer rows.Close()

	var users []*User
	for rows.Next() {
		user := &User{}
		if err := rows.Scan(&user.ID, &user.Name, &user.Password); err != nil {
			slog.Error("db: failed to scan user", "error", err)
			return nil, fmt.Errorf("failed to scan user")
		}
		users = append(users, user)
	}
	if err := rows.Err(); err != nil {
		slog.Error("db: row iteration error", "error", err)
		return nil, fmt.Errorf("failed to iterate users")
	}
	if len(users) == 0 {
		slog.Debug("db: no users found")
		return nil, errors.New("no users found")
	}

	slog.Debug("db: user list returned")
	return users, nil
}

func dbAddUser(user *User) error {
	query := `INSERT INTO users (id, name, password) VALUES ($1, $2, $3)`
	_, err := db.Pool.Exec(context.Background(), query, user.ID, user.Name, user.Password)
	if err != nil {
		slog.Error("db: failed to add user", "error", err, "userid", user.ID, "username", user.Name)
		return fmt.Errorf("failed to add user")
	}

	slog.Debug("db: user added", "userid", user.ID, "username", user.Name)
	return nil
}

func dbAddSession(session *Session) error {
	query := `INSERT INTO sessions (jwttoken, userid, expiry) VALUES ($1, $2, $3)`
	_, err := db.Pool.Exec(context.Background(), query, session.Token, session.UserID, session.Expiry)
	if err != nil {
		slog.Error("db: failed to add session", "error", err)
		return fmt.Errorf("failed to add session")
	}

	slog.Debug("db: session added", "userid", session.UserID)
	return nil
}

func dbGetSession(jwtToken string) (*Session, error) {
	query := `SELECT jwttoken, userid, expiry FROM sessions WHERE jwttoken = $1`

	var session Session
	err := db.Pool.QueryRow(context.Background(), query, jwtToken).Scan(&session.Token, &session.UserID, &session.Expiry)
	if errors.Is(err, pgx.ErrNoRows) {
		slog.Debug("db: session not found")
		return nil, ErrSessionNotFound
	} else if err != nil {
		slog.Error("db: failed to query session", "error", err)
		return nil, fmt.Errorf("failed to query session")
	}

	slog.Debug("db: session found", "userid", session.UserID)
	return &session, nil
}

func dbDeleteSession(jwtToken string) error {
	query := `DELETE FROM sessions WHERE jwttoken = $1`
	tag, err := db.Pool.Exec(context.Background(), query, jwtToken)
	if err != nil {
		slog.Error("db: failed to delete session", "error", err)
		return fmt.Errorf("failed to delete session")
	}
	if tag.RowsAffected() == 0 {
		return ErrSessionNotFound
	}

	slog.Debug("db: session deleted")
	return nil
}