package database

import (
	"log"

	"database/sql"

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

type Migrator func(*sql.DB) (*sql.DB, error)

func MigrateUsers(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating users table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS users (
		id TEXT PRIMARY KEY,
                mail TEXT NOT NULL,
		username TEXT NOT NULL,
                display_name TEXT NOT NULL,
		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	);`)
	if err != nil {
		return dbConn, err
	}

	log.Println("creating unique index on users table")
	_, err = dbConn.Exec(`CREATE UNIQUE INDEX IF NOT EXISTS idx_users_username ON users (username);`)
	if err != nil {
		return dbConn, err
	}

	return dbConn, nil
}

func MigrateApiKeys(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating api_keys table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS api_keys (
                key TEXT PRIMARY KEY,
		user_id INTEGER NOT NULL,
		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
		FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
	);`)
	if err != nil {
		return dbConn, err
	}
	return dbConn, nil
}

func MigrateDNSRecords(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating dns_records table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS dns_records (
		id TEXT PRIMARY KEY,
		user_id INTEGER NOT NULL,
		name TEXT NOT NULL,
		type TEXT NOT NULL,
		content TEXT NOT NULL,
		ttl INTEGER NOT NULL,
                internal BOOLEAN NOT NULL,
		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
		FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
        );`)
	if err != nil {
		return dbConn, err
	}

	_, err = dbConn.Exec(`CREATE UNIQUE INDEX IF NOT EXISTS idx_dns_records_name_content_type ON dns_records (name, type, content);`)
	if err != nil {
		return dbConn, err
	}

	return dbConn, nil
}

func MigrateDomainOwners(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating domain_owners table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS domain_owners (
		user_id INTEGER NOT NULL,
		domain TEXT NOT NULL,
		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
		FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
	);`)
	if err != nil {
		return dbConn, err
	}

	_, err = dbConn.Exec(`CREATE UNIQUE INDEX IF NOT EXISTS idx_domain_owners_domain ON domain_owners (domain);`)
	if err != nil {
		return dbConn, err
	}
	return dbConn, nil
}

func MigrateUserSessions(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating user_sessions table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS user_sessions (
		id TEXT PRIMARY KEY,
		user_id TEXT NOT NULL,
		expire_at TIMESTAMP NOT NULL,
		FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE
	);`)
	if err != nil {
		return dbConn, err
	}

	return dbConn, nil
}

func MigrateGuestBook(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating guest_book table")

	_, err := dbConn.Exec(`CREATE TABLE IF NOT EXISTS guest_book (
		id TEXT PRIMARY KEY,
		name TEXT NOT NULL,
		message TEXT NOT NULL,
		created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
	);`)
	if err != nil {
		return dbConn, err
	}

	_, err = dbConn.Exec(`CREATE INDEX IF NOT EXISTS idx_guest_book_created_at ON guest_book (created_at);`)

	return dbConn, nil
}

func MigrateProfiles(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating profiles columns")

	userColumns := map[string]bool{}
	row, err := dbConn.Query(`PRAGMA table_info(users);`)
	if err != nil {
		return dbConn, err
	}
	defer row.Close()

	for row.Next() {
		var columnName string
		row.Scan(nil, &columnName, nil, nil, nil, nil)
		userColumns[columnName] = true
	}

	columns := map[string]string{}
	columns["pronouns"] = "unspecified"
	columns["bio"] = "a computer hater"
	columns["location"] = "earth"
	columns["website"] = "https://hatecomputers.club"
	columns["avatar"] = "/static/img/default-avatar.png"

	for column, defaultValue := range columns {
		if userColumns[column] {
			continue
		}
		log.Println("migrating column", column)
		_, err = dbConn.Exec(`ALTER TABLE users ADD COLUMN ` + column + ` TEXT NOT NULL DEFAULT '` + defaultValue + `';`)
	}

	return dbConn, nil
}

func Migrate(dbConn *sql.DB) (*sql.DB, error) {
	log.Println("migrating database")

	migrations := []Migrator{
		MigrateUsers,
		MigrateUserSessions,
		MigrateApiKeys,
		MigrateDomainOwners,
		MigrateDNSRecords,
		MigrateGuestBook,
		MigrateProfiles,
	}

	for _, migration := range migrations {
		dbConn, err := migration(dbConn)
		if err != nil {
			return dbConn, err
		}
	}

	return dbConn, nil
}