import { migrate as migrate001 } from "./migrations/001";

async function migrate(): Promise<void> {
    if (!game.user.isGM) {
        return;
    }

    const oldMigrationVersion: number = game.settings.get("ds4", "systemMigrationVersion");

    const targetMigrationVersion = migrations.length;

    if (isFirstWorldStart(oldMigrationVersion)) {
        game.settings.set("ds4", "systemMigrationVersion", targetMigrationVersion);
        return;
    }

    return migrateFromTo(oldMigrationVersion, targetMigrationVersion);
}

async function migrateFromTo(oldMigrationVersion: number, targetMigrationVersion: number): Promise<void> {
    if (!game.user.isGM) {
        return;
    }

    const migrationsToExecute = migrations.slice(oldMigrationVersion, targetMigrationVersion);

    if (migrationsToExecute.length > 0) {
        ui.notifications.info(
            game.i18n.format("DS4.InfoSystemUpdateStart", {
                currentVersion: oldMigrationVersion,
                targetVersion: targetMigrationVersion,
            }),
            { permanent: true },
        );

        for (const [i, migration] of migrationsToExecute.entries()) {
            const currentMigrationVersion = oldMigrationVersion + i + 1;
            console.log("executing migration script ", currentMigrationVersion);
            try {
                await migration();
                game.settings.set("ds4", "systemMigrationVersion", currentMigrationVersion);
            } catch (err) {
                ui.notifications.error(
                    game.i18n.format("DS4.ErrorDuringMigration", {
                        currentVersion: oldMigrationVersion,
                        targetVersion: targetMigrationVersion,
                        migrationVersion: currentMigrationVersion,
                    }),
                    { permanent: true },
                );
                err.message = `Failed ds4 system migration: ${err.message}`;
                console.error(err);
                return;
            }
        }

        ui.notifications.info(
            game.i18n.format("DS4.InfoSystemUpdateCompleted", {
                currentVersion: oldMigrationVersion,
                targetVersion: targetMigrationVersion,
            }),
            { permanent: true },
        );
    }
}

function getTargetMigrationVersion(): number {
    return migrations.length;
}

const migrations: Array<() => Promise<void>> = [migrate001];

function isFirstWorldStart(migrationVersion: number): boolean {
    return migrationVersion < 0;
}

export const migration = {
    migrate: migrate,
    migrateFromTo: migrateFromTo,
    getTargetMigrationVersion: getTargetMigrationVersion,
};