import { spawnSync } from "node:child_process";
import { copyFileSync, readFileSync } from "node:fs";
import path from "node:path";
import Database from "better-sqlite3";
import { afterEach, describe, expect, it } from "vitest";
import {
  applyCommittedMigrations,
  createDisposableDatabase,
  disposeDisposableDatabase,
  type DisposableDatabase,
} from "./helpers/testDatabase";

const GROUP_MIGRATION = "20260807090000_add_material_groups";
const databases: DisposableDatabase[] = [];

afterEach(() => {
  for (const database of databases.splice(0)) {
    disposeDisposableDatabase(database);
  }
});

function create(options: { excludeGroup?: boolean } = {}) {
  const database = createDisposableDatabase();
  databases.push(database);
  applyCommittedMigrations(
    database,
    options.excludeGroup ? { through: "20260714010000_add_arcade" } : {}
  );
  return database;
}

function inspect(database: DisposableDatabase, args: string[] = []) {
  const result = spawnSync(
    process.execPath,
    [path.join(process.cwd(), "scripts", "migration-preflight.mjs"), ...args],
    {
      cwd: process.cwd(),
      env: { ...process.env, DATABASE_URL: database.databaseUrl },
      encoding: "utf8",
    }
  );
  return { status: result.status, output: JSON.parse(result.stdout) };
}

function migrationSql(migrationName: string) {
  return readFileSync(
    path.join(
      process.cwd(),
      "prisma",
      "migrations",
      migrationName,
      "migration.sql"
    ),
    "utf8"
  );
}

describe("material group migration preflight", () => {
  it("allows startup when a fresh database does not exist yet", () => {
    const database = createDisposableDatabase();
    databases.push(database);
    expect(inspect(database, ["--startup"])).toMatchObject({
      status: 0,
      output: { classification: "EMPTY", migrationsToAdopt: [] },
    });
  });

  it("preserves populated pre-group rows and relationships", () => {
    const database = create({ excludeGroup: true });
    const client = new Database(database.databasePath);
    try {
      client.pragma("foreign_keys = ON");
      client.prepare('INSERT INTO "Class" ("id", "slug", "name") VALUES (?, ?, ?)').run("class-1", "class", "Class");
      client.prepare('INSERT INTO "Deck" ("id", "classId", "name") VALUES (?, ?, ?)').run("deck-1", "class-1", "Deck");
      client.prepare('INSERT INTO "QuizSet" ("id", "classId", "name") VALUES (?, ?, ?)').run("quiz-1", "class-1", "Quiz");
      client.prepare('INSERT INTO "ShareLink" ("id", "targetType", "deckId") VALUES (?, ?, ?)').run("share-1", "DECK", "deck-1");
      client.exec(readFileSync(
        path.join(process.cwd(), "prisma", "migrations", GROUP_MIGRATION, "migration.sql"),
        "utf8"
      ));
      expect(client.prepare('SELECT COUNT(*) AS count FROM "Deck"').get()).toEqual({ count: 1 });
      expect(client.prepare('SELECT COUNT(*) AS count FROM "QuizSet"').get()).toEqual({ count: 1 });
      expect(client.prepare('SELECT "deckId", "groupId" FROM "ShareLink" WHERE "id" = ?').get("share-1")).toEqual({
        deckId: "deck-1",
        groupId: null,
      });
      expect(client.pragma("foreign_key_check")).toEqual([]);
    } finally {
      client.close();
    }
  });

  it("classifies a tracked pre-group database for normal apply", () => {
    expect(inspect(create({ excludeGroup: true }))).toMatchObject({
      status: 0,
      output: { classification: "APPLY", priorHistoryComplete: true },
    });
  });

  it("classifies an exact schema-pushed database for explicit adoption", () => {
    const database = create({ excludeGroup: true });
    const client = new Database(database.databasePath);
    client.exec(readFileSync(
      path.join(process.cwd(), "prisma", "migrations", GROUP_MIGRATION, "migration.sql"),
      "utf8"
    ));
    client.close();
    expect(inspect(database)).toMatchObject({
      status: 0,
      output: {
        classification: "ADOPT",
        priorHistoryComplete: true,
        exactSchema: { adoptedGroup: true },
      },
    });
  });

  it("blocks startup and explicitly adopts a fully schema-pushed database after P3018", () => {
    const database = create({ excludeGroup: true });
    const missingMigrations = [
      GROUP_MIGRATION,
      "20260807091000_add_quiz_attempt_snapshot",
      "20260807092000_add_progress_revisions",
    ];
    const client = new Database(database.databasePath);
    try {
      for (const migrationName of missingMigrations) {
        client.exec(migrationSql(migrationName));
      }
      client.prepare(`
        INSERT INTO "_prisma_migrations"
          ("id", "checksum", "finished_at", "migration_name", "logs", "applied_steps_count")
        VALUES (?, ?, NULL, ?, ?, 0)
      `).run("failed-group-migration", "failed", GROUP_MIGRATION, "P3018");
    } finally {
      client.close();
    }

    const startup = inspect(database, ["--startup"]);
    expect(startup).toMatchObject({
      status: 3,
      output: {
        classification: "ADOPT",
        migrationsToAdopt: missingMigrations,
      },
    });

    const backupPath = path.join(database.directory, "adoption-backup.test.db");
    copyFileSync(database.databasePath, backupPath);
    const resolve = spawnSync(
      process.execPath,
      [
        path.join(process.cwd(), "scripts", "migration-preflight.mjs"),
        "--resolve",
        "--backup",
        backupPath,
      ],
      {
        cwd: process.cwd(),
        env: { ...process.env, DATABASE_URL: database.databaseUrl },
        encoding: "utf8",
      }
    );
    expect(resolve.status, resolve.stderr).toBe(0);
    const deploy = spawnSync(
      process.execPath,
      [
        path.join(process.cwd(), "node_modules", "prisma", "build", "index.js"),
        "migrate",
        "deploy",
      ],
      {
        cwd: process.cwd(),
        env: { ...process.env, DATABASE_URL: database.databaseUrl },
        encoding: "utf8",
      }
    );
    expect(deploy.status, `${deploy.stdout}\n${deploy.stderr}`).toBe(0);
    expect(inspect(database)).toMatchObject({
      status: 0,
      output: { classification: "CURRENT", migrationsToAdopt: [] },
    });
  }, 30_000);

  it("can resume exact adoption after some missing migrations were recorded", () => {
    const database = create({ excludeGroup: true });
    const client = new Database(database.databasePath);
    try {
      for (const migrationName of [
        GROUP_MIGRATION,
        "20260807091000_add_quiz_attempt_snapshot",
        "20260807092000_add_progress_revisions",
      ]) {
        client.exec(migrationSql(migrationName));
      }
      client.prepare(`
        INSERT INTO "_prisma_migrations"
          ("id", "checksum", "finished_at", "migration_name", "applied_steps_count")
        VALUES (?, ?, current_timestamp, ?, 1)
      `).run("adopted-group-migration", "adopted", GROUP_MIGRATION);
    } finally {
      client.close();
    }

    expect(inspect(database, ["--startup"])).toMatchObject({
      status: 3,
      output: {
        classification: "ADOPT",
        migrationsToAdopt: [
          "20260807091000_add_quiz_attempt_snapshot",
          "20260807092000_add_progress_revisions",
        ],
      },
    });
  });

  it("rejects a partial schema without modifying it", () => {
    const database = create();
    const client = new Database(database.databasePath);
    client.exec('DROP INDEX "ShareLink_groupId_key"');
    const before = client
      .prepare("SELECT COUNT(*) AS count FROM _prisma_migrations")
      .get() as { count: number };
    client.close();

    expect(inspect(database)).toMatchObject({
      status: 2,
      output: { classification: "CONFLICT" },
    });

    const verification = new Database(database.databasePath, { readonly: true });
    const after = verification
      .prepare("SELECT COUNT(*) AS count FROM _prisma_migrations")
      .get() as { count: number };
    verification.close();
    expect(after.count).toBe(before.count);
  });

  it("does not accept the source database itself as the adoption backup", () => {
    const database = create({ excludeGroup: true });
    const client = new Database(database.databasePath);
    client.exec(readFileSync(
      path.join(process.cwd(), "prisma", "migrations", GROUP_MIGRATION, "migration.sql"),
      "utf8"
    ));
    client.close();

    const result = spawnSync(
      process.execPath,
      [
        path.join(process.cwd(), "scripts", "migration-preflight.mjs"),
        "--resolve",
        "--backup",
        database.databasePath,
      ],
      {
        cwd: process.cwd(),
        env: { ...process.env, DATABASE_URL: database.databaseUrl },
        encoding: "utf8",
      }
    );
    expect(result.status).not.toBe(0);
    expect(result.stderr).toContain("separate database file");
  });

  it("recognizes an already applied exact schema", () => {
    expect(inspect(create())).toMatchObject({
      status: 0,
      output: { classification: "CURRENT" },
    });
  });
});