/**
 * SurrealQL adapter — live SurrealDB v3 ledger regression suite.
 *
 * Reproduces the silent-ledger-drop discovered while shipping
 * `@suaveplan/api-plugin-database`: with the pre-fix code, the runner's
 * `CREATE ${table}:$name SET ...` form parses cleanly under SurrealDB v3
 * but records nothing, so the ledger reports zero applied migrations and
 * every boot re-runs the same migration.
 *
 * These tests run against a real `surrealdb:v3.x` testcontainer started by
 * `tests/integration/global-setup.ts`. No mocks.
 *
 * @module
 */
import { mkdtemp, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import {
    afterEach,
    beforeEach,
    describe,
    expect,
    it,
} from "@suaveplan/testing/runner";
import { Surreal } from "surrealdb";
import {
    createSurrealqlAdapter,
    type SurrealqlClient,
} from "../../src/adapters/surrealql/surrealql.js";
import { createMigrationRunner } from "../../src/runner/runner.js";
import { inject, surrealUnavailable } from "./integration-setup.js";

const TABLE = "_migrations";

/**
 * Thin wrapper that adapts the official `surrealdb` JS SDK to the structural
 * `SurrealqlClient` shape the migration adapter expects. The SDK's
 * `query<R extends unknown[]>(sql, bindings)` returns the raw statement-result
 * array; we flatten the single statement to the rows shape `selectApplied`
 * consumes.
 */
function wrapSurreal(client: Surreal): SurrealqlClient {
    return {
        async query<T>(
            sql: string,
            vars?: Record<string, unknown>
        ): Promise<T[]> {
            const result = (await client.query(sql, vars)) as unknown[];
            // `query` returns an array of statement results. For multi-
            // statement SQL we flatten everything that's an array of rows;
            // single-row results are tolerated.
            const flat: T[] = [];
            for (const r of result) {
                if (Array.isArray(r)) flat.push(...(r as T[]));
                else if (r !== null && r !== undefined) flat.push(r as T);
            }
            return flat;
        },
    };
}

async function connect(): Promise<Surreal> {
    const cfg = inject("surrealdb");
    const db = new Surreal();
    await db.connect(cfg.url);
    await db.signin({ username: cfg.username, password: cfg.password });
    await db.use({ namespace: cfg.namespace, database: cfg.database });
    return db;
}

describe.skipIf(surrealUnavailable)(
    "createSurrealqlAdapter — live SurrealDB v3 ledger",
    () => {
        let dir: string;
        let db: Surreal;

        beforeEach(async () => {
            dir = await mkdtemp(join(tmpdir(), "api-migrations-surreal-"));
            db = await connect();
            // Each test gets its own namespace/database for isolation. The
            // fixture's default ns/db are sufficient because we DROP the
            // ledger table in afterEach.
        }, 60000);

        afterEach(async () => {
            try {
                await db.query(`REMOVE TABLE ${TABLE};`);
            } catch {
                // best-effort cleanup
            }
            await db.close();
            await rm(dir, { recursive: true, force: true });
        }, 60000);

        it("ledger row is queryable after a migration body succeeds (regression: silent CREATE drop)", async () => {
            // Arrange: write a single migration body. The body creates a
            // table whose presence we can independently observe.
            const fileName = "001_initial.surql";
            const body = "DEFINE TABLE post_init SCHEMAFULL;";
            await writeFile(join(dir, fileName), body, "utf-8");

            const client = wrapSurreal(db);
            const adapter = createSurrealqlAdapter(client);
            const runner = createMigrationRunner(adapter, {
                tableName: TABLE,
                fileExtension: ".surql",
            });

            // Act
            const results = await runner.runFromDirectory(dir);

            // Assert 1: runner reports success.
            expect(results).toHaveLength(1);
            expect(results[0]!.success).toBe(true);
            expect(results[0]!.name).toBe("001_initial");

            // Assert 2: migration body actually applied.
            const bodyApplied = (await db.query("INFO FOR DB;")) as unknown[];
            expect(JSON.stringify(bodyApplied)).toContain("post_init");

            // Assert 3 (the regression): the ledger row exists in the
            // SAME live connection. With the pre-fix `${table}:$name`
            // form this query returns []; the runner re-applies the
            // migration on every boot.
            const ledgerRows = (await db.query(
                `SELECT name, checksum, duration FROM ${TABLE};`
            )) as Array<
                Array<{ name: string; checksum: string; duration: number }>
            >;
            const rows = ledgerRows[0] ?? [];
            expect(rows).toHaveLength(1);
            expect(rows[0]!.name).toBe("001_initial");
            expect(typeof rows[0]!.checksum).toBe("string");
            expect(rows[0]!.checksum).toMatch(/^[0-9a-f]{64}$/);
        }, 60000);

        it("second run sees the ledger and skips already-applied migrations", async () => {
            const fileName = "001_idempotent.surql";
            const body = "DEFINE TABLE idempotent_t SCHEMAFULL;";
            await writeFile(join(dir, fileName), body, "utf-8");

            const adapter = createSurrealqlAdapter(wrapSurreal(db));
            const runner = createMigrationRunner(adapter, {
                tableName: TABLE,
                fileExtension: ".surql",
            });

            const first = await runner.runFromDirectory(dir);
            expect(first).toHaveLength(1);

            // Second invocation MUST be a no-op. With the pre-fix bug
            // the ledger was empty so the runner would re-apply the
            // migration — which then fails because `DEFINE TABLE` is
            // idempotent here but in real schemas would crash on
            // duplicate constraints.
            const second = await runner.runFromDirectory(dir);
            expect(second).toEqual([]);

            // Ledger still has exactly one row.
            const ledgerRows = (await db.query(
                `SELECT name FROM ${TABLE};`
            )) as Array<Array<{ name: string }>>;
            expect(ledgerRows[0] ?? []).toHaveLength(1);
        }, 60000);

        it("rollback() removes the ledger row written by insertApplied (round-trip)", async () => {
            const fileName = "001_rollback.surql";
            const body = "DEFINE TABLE rollback_t SCHEMAFULL;";
            await writeFile(join(dir, fileName), body, "utf-8");

            const adapter = createSurrealqlAdapter(wrapSurreal(db));
            const runner = createMigrationRunner(adapter, {
                tableName: TABLE,
                fileExtension: ".surql",
            });
            await runner.runFromDirectory(dir);

            const result = await runner.rollback();
            expect(result?.success).toBe(true);
            expect(result?.name).toBe("001_rollback");

            const ledgerRows = (await db.query(
                `SELECT name FROM ${TABLE};`
            )) as Array<Array<{ name: string }>>;
            expect(ledgerRows[0] ?? []).toHaveLength(0);
        }, 60000);
    }
);