package database

import (
	"database/sql"
	"log"
	"time"

	_ "github.com/mattn/go-sqlite3"
)

const (
	ExpiryDuration = time.Hour * 24
)

type UserApiKey struct {
	Key       string    `json:"key"`
	UserID    string    `json:"user_id"`
	CreatedAt time.Time `json:"created_at"`
}

type User struct {
	ID          string    `json:"sub"`
	Mail        string    `json:"email"`
	Username    string    `json:"preferred_username"`
	DisplayName string    `json:"name"`
	CreatedAt   time.Time `json:"created_at"`
}

type UserSession struct {
	ID       string    `json:"id"`
	UserID   string    `json:"user_id"`
	ExpireAt time.Time `json:"expire_at"`
}

func GetUser(dbConn *sql.DB, id string) (*User, error) {
	log.Println("getting user", id)

	row := dbConn.QueryRow(`SELECT id, mail, username, display_name, created_at FROM users WHERE id = ?;`, id)

	var user User
	err := row.Scan(&user.ID, &user.Mail, &user.Username, &user.DisplayName, &user.CreatedAt)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	return &user, nil
}

func FindOrSaveUser(dbConn *sql.DB, user *User) (*User, error) {
	log.Println("finding or saving user", user.ID)

	_, err := dbConn.Exec(`INSERT INTO users (id, mail, username, display_name) VALUES (?, ?, ?, ?) ON CONFLICT(id) DO UPDATE SET mail = excluded.mail, username = excluded.username, display_name = excluded.display_name;`, user.ID, user.Mail, user.Username, user.DisplayName)
	if err != nil {
		return nil, err
	}

	return user, nil
}

func MakeUserSessionFor(dbConn *sql.DB, user *User) (*UserSession, error) {
	log.Println("making session for user", user.ID)

	expireAt := time.Now().Add(time.Hour * 12)

	_, err := dbConn.Exec(`INSERT OR REPLACE INTO user_sessions (id, user_id, expire_at) VALUES (?, ?, ?);`, user.ID, user.ID, time.Now().Add(ExpiryDuration))

	if err != nil {
		log.Println(err)
		return nil, err
	}

	return &UserSession{
		ID:       user.ID,
		UserID:   user.ID,
		ExpireAt: expireAt,
	}, nil
}

func GetSession(dbConn *sql.DB, sessionId string) (*UserSession, error) {
	log.Println("getting session", sessionId)

	row := dbConn.QueryRow(`SELECT id, user_id, expire_at FROM user_sessions WHERE id = ?;`, sessionId)

	var id, userId string
	var expireAt time.Time
	err := row.Scan(&id, &userId, &expireAt)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	return &UserSession{
		ID:       id,
		UserID:   userId,
		ExpireAt: expireAt,
	}, nil
}

func DeleteSession(dbConn *sql.DB, sessionId string) error {
	log.Println("deleting session", sessionId)

	_, err := dbConn.Exec(`DELETE FROM user_sessions WHERE id = ?;`, sessionId)
	if err != nil {
		log.Println(err)
		return err
	}

	return nil
}

func RefreshSession(dbConn *sql.DB, sessionId string) (*UserSession, error) {
	newExpireAt := time.Now().Add(ExpiryDuration)

	_, err := dbConn.Exec(`UPDATE user_sessions SET expire_at = ? WHERE id = ?;`, newExpireAt, sessionId)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	session, err := GetSession(dbConn, sessionId)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	return session, nil
}

func DeleteExpiredSessions(dbConn *sql.DB) error {
	_, err := dbConn.Exec(`DELETE FROM user_sessions WHERE expire_at < ?;`, time.Now())
	if err != nil {
		log.Println(err)
		return err
	}
	return nil
}

func CountUserAPIKeys(dbConn *sql.DB, userId string) (int, error) {
	log.Println("counting api keys for user", userId)

	row := dbConn.QueryRow(`SELECT COUNT(*) FROM api_keys WHERE user_id = ?;`, userId)

	var count int
	err := row.Scan(&count)
	if err != nil {
		log.Println(err)
		return 0, err
	}

	return count, nil
}

func ListUserAPIKeys(dbConn *sql.DB, userId string) ([]*UserApiKey, error) {
	log.Println("listing api keys for user", userId)

	rows, err := dbConn.Query(`SELECT key, user_id, created_at FROM api_keys WHERE user_id = ?;`, userId)
	if err != nil {
		log.Println(err)
		return nil, err
	}
	defer rows.Close()

	var apiKeys []*UserApiKey
	for rows.Next() {
		var apiKey UserApiKey
		err := rows.Scan(&apiKey.Key, &apiKey.UserID, &apiKey.CreatedAt)
		if err != nil {
			log.Println(err)
			return nil, err
		}

		apiKeys = append(apiKeys, &apiKey)
	}

	return apiKeys, nil
}

func SaveAPIKey(dbConn *sql.DB, apiKey *UserApiKey) (*UserApiKey, error) {
	log.Println("saving api key", apiKey.Key)

	_, err := dbConn.Exec(`INSERT OR REPLACE INTO api_keys (key, user_id) VALUES (?, ?);`, apiKey.Key, apiKey.UserID)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	apiKey.CreatedAt = time.Now()
	return apiKey, nil
}

func GetAPIKey(dbConn *sql.DB, key string) (*UserApiKey, error) {
	log.Println("getting api key", key)

	row := dbConn.QueryRow(`SELECT key, user_id, created_at FROM api_keys WHERE key = ?;`, key)

	var apiKey UserApiKey
	err := row.Scan(&apiKey.Key, &apiKey.UserID, &apiKey.CreatedAt)
	if err != nil {
		log.Println(err)
		return nil, err
	}

	return &apiKey, nil
}

func DeleteAPIKey(dbConn *sql.DB, key string) error {
	log.Println("deleting api key", key)

	_, err := dbConn.Exec(`DELETE FROM api_keys WHERE key = ?;`, key)
	if err != nil {
		log.Println(err)
		return err
	}

	return nil
}