import assert from "node:assert/strict";
import test from "node:test";
import type { Pool } from "pg";

import {
  clearLocalPostgresMetadataCacheForTests,
  closeLocalPostgresDataPool,
  createLocalPostgresDataClient,
  installLocalPostgresPoolForTests,
  setLocalPostgresMetadataClockForTests,
  type LocalDatabaseRole,
} from "../src/lib/db/local-postgres-client-core.ts";

type QueryCall = { sql: string; params: readonly unknown[] };

function tag(sql: string): string {
  const compact = sql.replace(/\s+/g, " ").trim().toLowerCase();
  if (compact === "begin") return "begin";
  if (compact === "commit") return "commit";
  if (compact === "rollback") return "rollback";
  if (compact.startsWith("set local role")) return "set local role";
  if (compact.includes("set_config('role'")) return "set_config(role)";
  if (compact.includes("set_config('request.jwt.claim.sub'")) return "set_config";
  if (compact.includes("information_schema.columns")) return "information_schema";
  if (compact.includes("from pg_index")) return "primary_key";
  if (compact.includes("from pg_proc")) return "pg_proc";
  return "business";
}

function installFakePool(
  url: string,
  options: {
    columns?: ReadonlyArray<{ column_name: string; udt_name: string }> | null;
    primaryKeys?: readonly string[] | null;
    functions?: ReadonlyArray<Record<string, unknown>> | null;
    failBusinessCode?: () => string | null;
  } = {},
): QueryCall[] {
  const calls: QueryCall[] = [];
  const client = {
    async query(sql: string, params: readonly unknown[] = []) {
      calls.push({ sql, params });
      const label = tag(sql);
      if (label === "information_schema") {
        const rows = options.columns === null
          ? []
          : [...(options.columns ?? [{ column_name: "id", udt_name: "uuid" }])];
        return { rows, rowCount: rows.length };
      }
      if (label === "primary_key") {
        const names = options.primaryKeys === null ? [] : [...(options.primaryKeys ?? ["id"])];
        const rows = names.map((column_name) => ({ column_name }));
        return { rows, rowCount: rows.length };
      }
      if (label === "pg_proc") {
        const rows = options.functions === null
          ? []
          : [...(options.functions ?? [{
            proretset: false,
            return_type: "text",
            argument_names: ["left_name", "right_name"],
            argument_types: ["text", "text"],
          }])];
        return { rows, rowCount: rows.length };
      }
      if (label === "business") {
        const code = options.failBusinessCode?.() ?? null;
        if (code) {
          const error = new Error("business sql failed") as Error & { code: string };
          error.code = code;
          throw error;
        }
        if (sql.toLowerCase().includes(" as value")) return { rows: [{ value: "ok" }], rowCount: 1 };
      }
      return { rows: [], rowCount: 0 };
    },
    release() {},
  };
  const pool = {
    async connect() {
      return client;
    },
    async end() {},
  };
  installLocalPostgresPoolForTests(url, pool as unknown as Pool);
  return calls;
}

async function withSwitches(
  values: Record<string, string | undefined>,
  run: () => Promise<void>,
): Promise<void> {
  const previous = new Map<string, string | undefined>();
  for (const [key, value] of Object.entries(values)) {
    previous.set(key, process.env[key]);
    if (value === undefined) delete process.env[key];
    else process.env[key] = value;
  }
  clearLocalPostgresMetadataCacheForTests();
  setLocalPostgresMetadataClockForTests(null);
  try {
    await run();
  } finally {
    for (const [key, value] of previous) {
      if (value === undefined) delete process.env[key];
      else process.env[key] = value;
    }
    clearLocalPostgresMetadataCacheForTests();
    setLocalPostgresMetadataClockForTests(null);
  }
}

const identity = { id: "018f4e6d-7a11-7000-8000-0000000000aa", email: "person@example.com" };

function clientFor(url: string, role: LocalDatabaseRole | null = "authenticated") {
  return createLocalPostgresDataClient(url, role === "service_role" ? null : identity, role);
}

test("metadata cache and merged session setup stay off the baseline query sequence", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "off",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "off",
  }, async () => {
    const url = "postgresql://roundtrip-off@127.0.0.1:1/jyotisha";
    const calls = installFakePool(url);
    const client = clientFor(url);
    const first = await client.from("profiles").select("id").eq("id", identity.id);
    assert.equal(first.error, null);
    assert.deepEqual(calls.map((call) => tag(call.sql)), [
      "begin",
      "set local role",
      "set_config",
      "information_schema",
      "business",
      "commit",
    ]);
    await client.from("profiles").select("id").eq("id", identity.id);
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 2);
  });
});

test("cached metadata and merged session setup drop a repeat select and rpc to four roundtrips", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "on",
  }, async () => {
    const url = "postgresql://roundtrip-on@127.0.0.1:1/jyotisha";
    const calls = installFakePool(url);
    const client = clientFor(url);
    await client.from("profiles").select("id").eq("id", identity.id);
    calls.length = 0;
    await client.from("profiles").select("id").eq("id", identity.id);
    assert.deepEqual(calls.map((call) => tag(call.sql)), [
      "begin",
      "set_config(role)",
      "business",
      "commit",
    ]);

    await client.rpc("sample_probe", { left_name: "a", right_name: "b" });
    calls.length = 0;
    const rpc = await client.rpc("sample_probe", { left_name: "a", right_name: "b" });
    assert.equal(rpc.error, null);
    assert.deepEqual(calls.map((call) => tag(call.sql)), [
      "begin",
      "set_config(role)",
      "business",
      "commit",
    ]);

    await client.from("profiles").upsert({ id: identity.id });
    calls.length = 0;
    await client.from("profiles").upsert({ id: identity.id });
    assert.deepEqual(calls.map((call) => tag(call.sql)), [
      "begin",
      "set_config(role)",
      "business",
      "commit",
    ]);
  });
});

test("column cache is per role and function cache is per argument names", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "on",
  }, async () => {
    const url = "postgresql://roundtrip-keys@127.0.0.1:1/jyotisha";
    const calls = installFakePool(url);
    const authenticated = clientFor(url, "authenticated");
    const service = clientFor(url, "service_role");
    await authenticated.from("profiles").select("id");
    calls.length = 0;
    await service.from("profiles").select("id");
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 1);

    await authenticated.rpc("sample_probe", { left_name: "a" });
    calls.length = 0;
    await authenticated.rpc("sample_probe", { right_name: "b" });
    assert.equal(calls.filter((call) => tag(call.sql) === "pg_proc").length, 1);
  });
});

test("undefined column, expiry, pool close, and empty metadata all miss the cache", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "off",
  }, async () => {
    const url = "postgresql://roundtrip-invalidate@127.0.0.1:1/jyotisha";
    let failuresLeft = 1;
    const calls = installFakePool(url, {
      failBusinessCode: () => {
        if (failuresLeft <= 0) return null;
        failuresLeft -= 1;
        return "42703";
      },
    });
    const client = clientFor(url);
    const failed = await client.from("profiles").select("id");
    assert.equal(failed.error?.code, "42703");
    calls.length = 0;
    const retried = await client.from("profiles").select("id");
    assert.equal(retried.error, null);
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 1);
  });
});

test("metadata older than 300 seconds is queried again", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "off",
  }, async () => {
    const url = "postgresql://roundtrip-ttl@127.0.0.1:1/jyotisha";
    let now = 10_000;
    setLocalPostgresMetadataClockForTests(() => now);
    const calls = installFakePool(url);
    const client = clientFor(url);
    await client.from("profiles").select("id");
    calls.length = 0;
    await client.from("profiles").select("id");
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 0);
    now += 300_000;
    calls.length = 0;
    await client.from("profiles").select("id");
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 1);
  });
});

test("an empty column list and a missing function are not cached", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "off",
  }, async () => {
    const url = "postgresql://roundtrip-empty@127.0.0.1:1/jyotisha";
    const calls = installFakePool(url, { columns: null, functions: null, primaryKeys: null });
    const client = clientFor(url);
    await client.from("profiles").select("id");
    calls.length = 0;
    await client.from("profiles").select("id");
    assert.equal(calls.filter((call) => tag(call.sql) === "information_schema").length, 1);

    const missing = await client.rpc("missing_probe", { left_name: "a" });
    assert.match(missing.error?.message ?? "", /not found/);
    calls.length = 0;
    await client.rpc("missing_probe", { left_name: "a" });
    assert.equal(calls.filter((call) => tag(call.sql) === "pg_proc").length, 1);
  });
});

test("closing the pool drops that url from the metadata cache", async () => {
  await withSwitches({
    JYOTISHA_PG_METADATA_CACHE: "on",
    JYOTISHA_PG_MERGED_SESSION_SETUP: "off",
  }, async () => {
    const url = "postgresql://roundtrip-close@127.0.0.1:1/jyotisha";
    const calls = installFakePool(url);
    const client = clientFor(url);
    await client.from("profiles").select("id");
    await closeLocalPostgresDataPool(url);
    const reopenedCalls = installFakePool(url);
    const reopened = clientFor(url);
    await reopened.from("profiles").select("id");
    assert.equal(reopenedCalls.filter((call) => tag(call.sql) === "information_schema").length, 1);
    assert.ok(calls.length > 0);
  });
});