import { randomBytes } from "node:crypto";
import { mkdtemp, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { Client, type QueryResultRow } from "pg";
import { afterAll, describe, expect, it } from "vitest";
import {
  createDashboardDrizzleView,
  createDashboardStore,
  type DashboardStore,
  DashboardStoreError,
  resolveDashboardNavigation,
} from "../src/dashboard/index.js";
import { createValidatedPostgresPool } from "../src/database/index.js";
import {
  applyModuleMigrations,
  createPostgresMigrationDatabase,
  discoverAllMigrations,
} from "../src/migrations/index.js";

/**
 * The Dashboard navigation store against real PostgreSQL.
 *
 * The unit suites prove the resolution rules; this proves the things only a database can: that the
 * migration really creates these tables, that configuration survives a completely new connection,
 * that `on delete set null` really ungroups a deleted group's modules, and that a placement can
 * never point at a group that does not exist. The in-memory double used by the API route tests
 * deliberately reproduces only two of those behaviours, so this file is where they are actually
 * established rather than assumed.
 */
const integrationDatabaseUrlEnvironment = "EKKLESIA_MIGRATION_TEST_DATABASE_URL";
const coreMigrationsDirectory = path.join(
  path.dirname(fileURLToPath(import.meta.url)),
  "..",
  "drizzle",
);
const trackedDatabases = new Set<string>();
let databaseCounter = 0;

class IntegrationHarnessError extends Error {
  constructor(message: string) {
    super(message);
    this.name = "IntegrationHarnessError";
    this.stack = `${this.name}: ${this.message}`;
  }
}

function harnessError(message: string): IntegrationHarnessError {
  return new IntegrationHarnessError(message);
}

function baseDatabaseUrl(): string {
  const value = process.env[integrationDatabaseUrlEnvironment];
  if (typeof value !== "string" || value.trim() === "") {
    throw harnessError("The Dashboard integration database is not configured.");
  }
  try {
    const parsed = new URL(value);
    if (parsed.protocol !== "postgres:" && parsed.protocol !== "postgresql:") {
      throw new TypeError("Unsupported protocol.");
    }
  } catch {
    throw harnessError("The Dashboard integration database configuration is invalid.");
  }
  return value;
}

function quoteDatabaseName(databaseName: string): string {
  if (!/^[a-z][a-z0-9_]{0,62}$/u.test(databaseName)) {
    throw harnessError("The generated integration database name is invalid.");
  }
  return `"${databaseName}"`;
}

function makeDatabaseName(label: string): string {
  const safeLabel = label
    .toLowerCase()
    .replaceAll(/[^a-z0-9]+/gu, "_")
    .replaceAll(/^_+|_+$/gu, "")
    .slice(0, 14);
  databaseCounter += 1;
  return `ekk_dash_${process.pid}_${databaseCounter}_${safeLabel || "scenario"}_${randomBytes(4).toString("hex")}`;
}

function databaseUrl(databaseName: string): string {
  const parsed = new URL(baseDatabaseUrl());
  parsed.pathname = `/${databaseName}`;
  parsed.searchParams.delete("application_name");
  return parsed.toString();
}

async function openAdministrativeClient(connectionString: string): Promise<Client> {
  const client = new Client({ connectionString });
  client.on("error", () => undefined);
  try {
    await client.connect();
    return client;
  } catch {
    try {
      await client.end();
    } catch {
      // The public harness failure stays static when connection cleanup also fails.
    }
    throw harnessError("The Dashboard integration database connection failed.");
  }
}

async function safeQuery<Row extends QueryResultRow>(
  client: Client,
  text: string,
  values: unknown[] = [],
): Promise<readonly Row[]> {
  try {
    const result = await client.query<Row>(text, values);
    return result.rows;
  } catch {
    throw harnessError("An integration database administration operation failed.");
  }
}

async function safeEnd(client: Client): Promise<void> {
  try {
    await client.end();
  } catch {
    throw harnessError("An integration database connection could not be closed.");
  }
}

async function dropDatabase(databaseName: string): Promise<void> {
  const admin = await openAdministrativeClient(baseDatabaseUrl());
  try {
    await safeQuery(
      admin,
      "SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname = $1 AND pid <> pg_backend_pid()",
      [databaseName],
    );
    await safeQuery(
      admin,
      `DROP DATABASE IF EXISTS ${quoteDatabaseName(databaseName)} WITH (FORCE)`,
    );
    trackedDatabases.delete(databaseName);
  } finally {
    await safeEnd(admin);
  }
}

async function createDisposableDatabase(label: string): Promise<{ name: string; url: string }> {
  const name = makeDatabaseName(label);
  const admin = await openAdministrativeClient(baseDatabaseUrl());
  try {
    await safeQuery(admin, `CREATE DATABASE ${quoteDatabaseName(name)} TEMPLATE template0`);
  } finally {
    await safeEnd(admin);
  }
  trackedDatabases.add(name);
  return { name, url: databaseUrl(name) };
}

async function applyCoreMigrations(url: string): Promise<void> {
  const emptyModulesDirectory = await mkdtemp(path.join(tmpdir(), "ekklesia-dash-no-modules-"));
  try {
    const aggregate = await discoverAllMigrations({
      coreMigrationsDirectory,
      moduleDiscovery: {
        moduleSdkVersion: "0.1.0",
        modulesDirectory: emptyModulesDirectory,
        platformVersion: "0.1.0",
      },
    });
    expect(aggregate.migrations.map((entry) => entry.identity)).toEqual([
      "core:0000_identity_core_tables",
      "core:0001_authorization_core_tables",
      "core:0002_authorization_integrity",
      "core:0003_dashboard_navigation_tables",
      "core:0004_module_lifecycle_state",
      "core:0005_module_configuration",
    ]);
    await applyModuleMigrations({ aggregate, database: createPostgresMigrationDatabase(url) });
  } finally {
    await rm(emptyModulesDirectory, { force: true, recursive: true });
  }
}

afterAll(async () => {
  for (const databaseName of [...trackedDatabases]) {
    await dropDatabase(databaseName).catch(() => undefined);
  }
});

describe.sequential("live Core Dashboard navigation store", () => {
  let database: { name: string; url: string };
  let admin: Client;
  let store: DashboardStore;
  let close: () => Promise<void>;

  it("creates exactly the two Dashboard tables, with their constraints", async () => {
    database = await createDisposableDatabase("fresh");
    await applyCoreMigrations(database.url);
    admin = await openAdministrativeClient(database.url);

    const tables = await safeQuery<{ table_name: string }>(
      admin,
      `select table_name from information_schema.tables
        where table_schema = 'public' and table_name like 'ekklesia_core_dashboard%'
        order by table_name`,
    );
    const constraints = await safeQuery<{ constraint_name: string; delete_rule: string }>(
      admin,
      `select rc.constraint_name, rc.delete_rule
         from information_schema.referential_constraints rc
         join information_schema.table_constraints tc
           on tc.constraint_name = rc.constraint_name
        where tc.table_name = 'ekklesia_core_dashboard_placement'`,
    );

    expect(tables.map((table) => table.table_name)).toEqual([
      "ekklesia_core_dashboard_group",
      "ekklesia_core_dashboard_placement",
    ]);
    // The database, not the application, is what guarantees a deleted group leaves no dangling
    // reference.
    expect(constraints.map((constraint) => constraint.delete_rule)).toEqual(["SET NULL"]);

    const handle = createValidatedPostgresPool(database.url);
    close = handle.close;
    store = createDashboardStore(createDashboardDrizzleView(handle.pool));
  });

  it("starts empty, so an installation with no configuration is a normal state", async () => {
    expect(await store.readConfiguration()).toEqual({ groups: [], placements: [] });
  });

  it("persists groups and placements, and reads them back in deterministic order", async () => {
    await store.upsertGroup({ id: "planning", label: "Planning", sortOrder: 20 });
    await store.upsertGroup({ id: "media", label: "Media", sortOrder: 10 });
    await store.setPlacement({ groupId: "media", moduleId: "livestream", sortOrder: 20 });
    await store.setPlacement({ groupId: "media", moduleId: "video", sortOrder: 10 });
    await store.setPlacement({ groupId: "planning", moduleId: "calendar", sortOrder: 10 });

    const configuration = await store.readConfiguration();

    expect(configuration.groups.map((group) => group.id)).toEqual(["media", "planning"]);
    expect(configuration.placements.map((placement) => placement.moduleId)).toEqual([
      "calendar",
      "video",
      "livestream",
    ]);
  });

  it("survives a completely new connection, so a church configures its Dashboard once", async () => {
    // A different pool, as a restarted process would use — nothing is cached in the old one.
    const reopened = createValidatedPostgresPool(database.url);
    try {
      const configuration = await createDashboardStore(
        createDashboardDrizzleView(reopened.pool),
      ).readConfiguration();
      const view = resolveDashboardNavigation(configuration, [
        { id: "livestream", name: "Livestream" },
        { id: "video", name: "Video" },
        { id: "calendar", name: "Calendar" },
      ]);

      expect(
        view.groups.map((group) => [group.label, group.modules.map((entry) => entry.name)]),
      ).toEqual([
        ["Media", ["Video", "Livestream"]],
        ["Planning", ["Calendar"]],
      ]);
    } finally {
      await reopened.close();
    }
  });

  it("renames a group without disturbing a single placement", async () => {
    const before = await store.readConfiguration();

    await store.upsertGroup({ id: "media", label: "Media & Streaming", sortOrder: 10 });
    const after = await store.readConfiguration();

    expect(after.groups.find((group) => group.id === "media")?.label).toBe("Media & Streaming");
    // The stable id is what placements point at, so a rename can never re-organize the Dashboard.
    expect(after.placements).toEqual(before.placements);
  });

  it("re-orders a group and a module in place, without creating duplicates", async () => {
    await store.upsertGroup({ id: "media", label: "Media & Streaming", sortOrder: 30 });
    await store.setPlacement({ groupId: "media", moduleId: "video", sortOrder: 99 });

    const configuration = await store.readConfiguration();

    expect(configuration.groups).toHaveLength(2);
    expect(configuration.groups.map((group) => group.id)).toEqual(["planning", "media"]);
    expect(configuration.placements.filter((entry) => entry.moduleId === "video")).toHaveLength(1);
    expect(configuration.placements.find((entry) => entry.moduleId === "video")?.sortOrder).toBe(
      99,
    );
  });

  it("moves a module between groups by changing exactly one row", async () => {
    await store.upsertGroup({ id: "sunday-production", label: "Sunday Production", sortOrder: 5 });
    await store.setPlacement({
      groupId: "sunday-production",
      moduleId: "livestream",
      sortOrder: 10,
    });

    const configuration = await store.readConfiguration();

    expect(configuration.placements.find((entry) => entry.moduleId === "livestream")?.groupId).toBe(
      "sunday-production",
    );
    // Video did not move.
    expect(configuration.placements.find((entry) => entry.moduleId === "video")?.groupId).toBe(
      "media",
    );
  });

  it("ungroups a module deliberately, which is distinct from having no record", async () => {
    await store.setPlacement({ groupId: null, moduleId: "calendar", sortOrder: 7 });

    const configuration = await store.readConfiguration();
    const calendar = configuration.placements.find((entry) => entry.moduleId === "calendar");

    expect(calendar).toEqual({ groupId: null, moduleId: "calendar", sortOrder: 7 });
  });

  it("ungroups a deleted group's modules instead of leaving a dangling reference", async () => {
    await store.deleteGroup("sunday-production");

    const configuration = await store.readConfiguration();
    const groupIds = new Set(configuration.groups.map((group) => group.id));

    expect(groupIds.has("sunday-production")).toBe(false);
    expect(
      configuration.placements.find((entry) => entry.moduleId === "livestream")?.groupId,
    ).toBeNull();
    // No placement anywhere names a group that no longer exists.
    for (const placement of configuration.placements) {
      if (placement.groupId !== null) {
        expect(groupIds.has(placement.groupId)).toBe(true);
      }
    }
  });

  it("refuses a placement naming a group that was never created", async () => {
    await expect(
      store.setPlacement({ groupId: "not-a-group", moduleId: "video", sortOrder: 10 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_GROUP_NOT_FOUND" });
  });

  it("refuses to delete a group that does not exist", async () => {
    await expect(store.deleteGroup("not-a-group")).rejects.toMatchObject({
      code: "DASHBOARD_GROUP_NOT_FOUND",
    });
  });

  it("stores a placement for a module that is not installed, and renders nothing for it", async () => {
    await store.upsertGroup({ id: "media", label: "Media & Streaming", sortOrder: 30 });
    await store.setPlacement({ groupId: "media", moduleId: "uninstalled", sortOrder: 1 });

    const configuration = await store.readConfiguration();
    const view = resolveDashboardNavigation(configuration, [{ id: "video", name: "Video" }]);

    // Retained, so a reinstall restores the position...
    expect(configuration.placements.map((entry) => entry.moduleId)).toContain("uninstalled");
    // ...and never rendered while the module is absent.
    expect(
      [...view.groups.flatMap((group) => group.modules), ...view.ungrouped].map(
        (entry) => entry.id,
      ),
    ).toEqual(["video"]);
  });

  it("rejects malformed input before it reaches the database", async () => {
    await expect(
      store.upsertGroup({ id: "Not Kebab Case", label: "Nope", sortOrder: 0 }),
    ).rejects.toBeInstanceOf(DashboardStoreError);
    await expect(
      store.upsertGroup({ id: "media", label: "   ", sortOrder: 0 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_GROUP_LABEL_INVALID" });
    await expect(
      store.upsertGroup({ id: "media", label: "x".repeat(121), sortOrder: 0 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_GROUP_LABEL_INVALID" });
    await expect(
      store.upsertGroup({ id: "media", label: "Media", sortOrder: -1 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_SORT_ORDER_INVALID" });
    await expect(
      store.setPlacement({ groupId: null, moduleId: "Not Valid", sortOrder: 0 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_MODULE_ID_INVALID" });
    await expect(
      store.setPlacement({ groupId: null, moduleId: "video", sortOrder: 1.5 }),
    ).rejects.toMatchObject({ code: "DASHBOARD_SORT_ORDER_INVALID" });
  });

  it("trims a stored label rather than persisting surrounding whitespace", async () => {
    await store.upsertGroup({ id: "planning", label: "  Planning  ", sortOrder: 20 });

    const configuration = await store.readConfiguration();

    expect(configuration.groups.find((group) => group.id === "planning")?.label).toBe("Planning");
  });

  it("leaks no database detail in a sanitized failure", async () => {
    await close();

    const error = await store.readConfiguration().catch((caught: unknown) => caught);
    const text = `${String(error)}\n${(error as Error).stack ?? ""}`;

    expect(error).toMatchObject({ code: "DASHBOARD_READ_FAILED" });
    expect(text).not.toContain(database.name);
    expect(text).not.toContain("select");
    expect(text).not.toContain("ekklesia_core_dashboard");
    await safeEnd(admin);
    await dropDatabase(database.name);
  });
});