import { createHmac } from "node:crypto";
import { afterEach, describe, expect, it } from "vitest";

import {
  issueDocverToken,
  parseTokenRequestBody,
  requireDocverApiKey,
  requireDocverBearer,
  verifyDocverToken,
  type DocverTokenClaims,
} from "@/lib/docver-token";

// docver token (PLAN-DOCVER.md §auth) — validation/auth ล้วนของ /api/documents/*:
// ไฟล์นี้ตั้งใจไม่แตะ module ใดที่ลาก @/db หรือ minio มาด้วย (pattern เดียวกับ
// external-api-auth.test.ts — vitest ไม่โหลด .env จึงต้องรันได้โดยไม่ต้องตั้ง
// DATABASE_URL/MINIO_*)

const SECRET = "test-secret-docver";
const CLAIMS: DocverTokenClaims = {
  userid: "123",
  username: "Sorawit Bholsithi",
  fid: "3",
  template: "T12",
};

function ok<T>(result: { ok: boolean } & T): asserts result is { ok: true } & T {
  expect(result.ok).toBe(true);
}

// --- env save/restore — require* อ่าน env ตอนเรียก ไม่ใช่ตอน module load
const HAD_API_KEY = Object.prototype.hasOwnProperty.call(process.env, "DOCVER_API_KEY");
const ORIG_API_KEY = process.env.DOCVER_API_KEY;
const HAD_SECRET = Object.prototype.hasOwnProperty.call(process.env, "DOCVER_TOKEN_SECRET");
const ORIG_SECRET = process.env.DOCVER_TOKEN_SECRET;

afterEach(() => {
  if (HAD_API_KEY) process.env.DOCVER_API_KEY = ORIG_API_KEY;
  else delete process.env.DOCVER_API_KEY;
  if (HAD_SECRET) process.env.DOCVER_TOKEN_SECRET = ORIG_SECRET;
  else delete process.env.DOCVER_TOKEN_SECRET;
});

function reqWithKey(key?: string): Request {
  return new Request("http://localhost/docedit/api/documents/token", {
    headers: key === undefined ? {} : { "x-api-key": key },
  });
}

function reqWithBearer(authorization: string | null): Request {
  return new Request("http://localhost/docedit/api/documents/doc1/versions", {
    headers: authorization === null ? {} : { authorization },
  });
}

async function bodyOf(res: Response): Promise<{ error: string }> {
  expect(res.headers.get("content-type")).toBe("application/json; charset=utf-8");
  return (await res.json()) as { error: string };
}

/** เซ็น payload ใด ๆ ด้วย SECRET ผ่านมือ — ใช้ประกอบเคส claims ผิดรูปที่ issueDocverToken สร้างเองไม่ได้ */
function signPayload(payload: Record<string, unknown>): string {
  const header = Buffer.from(JSON.stringify({ alg: "HS256", typ: "JWT" }), "utf8").toString(
    "base64url",
  );
  const body = Buffer.from(JSON.stringify(payload), "utf8").toString("base64url");
  const signature = createHmac("sha256", SECRET)
    .update(`${header}.${body}`)
    .digest("base64url");
  return `${header}.${body}.${signature}`;
}

describe("issueDocverToken / verifyDocverToken", () => {
  it("issue → verify ได้ claims ครบทุกตัว (userid/username/fid/template)", () => {
    const verified = verifyDocverToken(issueDocverToken(CLAIMS, SECRET, 60), SECRET);
    ok(verified);
    expect(verified.claims).toEqual(CLAIMS);
  });

  it("template เป็นทางเลือก (null ได้) แต่ fid บังคับ — token ไม่มี fid = ไม่ผ่าน", () => {
    const verified = verifyDocverToken(
      issueDocverToken({ userid: "u1", username: "ชื่อ", fid: "7", template: null }, SECRET, 60),
      SECRET,
    );
    ok(verified);
    expect(verified.claims).toEqual({ userid: "u1", username: "ชื่อ", fid: "7", template: null });
    const noFid = signPayload({
      userid: "u1",
      username: "n",
      template: "T1",
      iat: 0,
      exp: Math.floor(Date.now() / 1000) + 60,
    });
    expect(verifyDocverToken(noFid, SECRET).ok).toBe(false);
  });

  it("แก้ payload แล้วใช้ signature เดิม (tampered) หรือ secret ผิด = ไม่ผ่าน", () => {
    const token = issueDocverToken(CLAIMS, SECRET, 60);
    const [header, , signature] = token.split(".");
    const tamperedPayload = Buffer.from(
      JSON.stringify({ ...CLAIMS, userid: "999" }),
      "utf8",
    ).toString("base64url");
    expect(verifyDocverToken(`${header}.${tamperedPayload}.${signature}`, SECRET).ok).toBe(false);
    expect(verifyDocverToken(token, "wrong-secret").ok).toBe(false);
  });

  it("header alg อื่น (none / HS512) = ไม่ผ่าน แม้จะเซ็นด้วย secret ถูก (กัน alg-confusion)", () => {
    const body = Buffer.from(
      JSON.stringify({ ...CLAIMS, iat: 0, exp: Math.floor(Date.now() / 1000) + 60 }),
      "utf8",
    ).toString("base64url");
    for (const alg of ["none", "HS512"]) {
      const header = Buffer.from(JSON.stringify({ alg, typ: "JWT" }), "utf8").toString("base64url");
      const signature = createHmac("sha256", SECRET)
        .update(`${header}.${body}`)
        .digest("base64url");
      expect(verifyDocverToken(`${header}.${body}.${signature}`, SECRET).ok).toBe(false);
    }
  });

  it("token หมดอายุ (ttl ติดลบ) หรือไม่มี exp = ไม่ผ่าน", () => {
    expect(verifyDocverToken(issueDocverToken(CLAIMS, SECRET, -10), SECRET).ok).toBe(false);
    const noExp = signPayload({ ...CLAIMS, iat: Math.floor(Date.now() / 1000) });
    expect(verifyDocverToken(noExp, SECRET).ok).toBe(false);
  });

  it("claims ไม่ครบรูปร่าง (แม้เซ็นถูก) = ไม่ผ่าน — กัน token เซ็นเองหลุดไปใช้", () => {
    const now = Math.floor(Date.now() / 1000) + 60;
    for (const bad of [
      { username: "n", fid: "3", template: null, iat: 0, exp: now }, // ไม่มี userid
      { userid: "u", fid: "3", template: null, iat: 0, exp: now }, // ไม่มี username
      { userid: "", username: "n", fid: "3", template: null, iat: 0, exp: now }, // userid ว่าง
      { userid: "u", username: "n", fid: 3, template: null, iat: 0, exp: now }, // fid เป็น number
      { userid: "u", username: "n", fid: "", template: null, iat: 0, exp: now }, // fid ว่าง
      { userid: "u", username: "n", template: null, iat: 0, exp: now }, // ไม่มี fid (บังคับแล้ว)
      { userid: "u", username: "n", fid: null, template: null, iat: 0, exp: now }, // fid null
    ]) {
      expect(verifyDocverToken(signPayload(bad), SECRET).ok).toBe(false);
    }
  });

  it("รูป token ผิด (ไม่ใช่ 3 segment / segment เป็น base64 ปกติไม่ใช่ base64url) = ไม่ผ่าน", () => {
    expect(verifyDocverToken("not-a-jwt", SECRET).ok).toBe(false);
    expect(verifyDocverToken("a.b.c.d", SECRET).ok).toBe(false);
    // base64 ปกติมี + / ซึ่ง base64url decode แล้วได้ byte ผิด → header/payload พัง
    expect(verifyDocverToken("???.???.???", SECRET).ok).toBe(false);
  });
});

describe("requireDocverApiKey", () => {
  it("env ไม่ตั้ง / ว่าง / ช่องว่างล้วน = 401 fail closed ทุกกรณี", async () => {
    for (const value of [undefined, "", "   "]) {
      if (value === undefined) delete process.env.DOCVER_API_KEY;
      else process.env.DOCVER_API_KEY = value;
      const res = requireDocverApiKey(reqWithKey("test-key"));
      expect(res?.status).toBe(401);
      expect(await bodyOf(res!)).toEqual({ error: "ระบบยังไม่ได้ตั้งค่า API key" });
    }
  });

  it("ไม่ใส่ header กับ key ผิด ต้องได้ 401 ข้อความเดียวกันเป๊ะ (กัน enumerate)", async () => {
    process.env.DOCVER_API_KEY = "test-key";
    const missing = requireDocverApiKey(reqWithKey());
    const wrong = requireDocverApiKey(reqWithKey("not-the-key"));
    expect(missing?.status).toBe(401);
    expect(wrong?.status).toBe(401);
    expect(await bodyOf(missing!)).toEqual(await bodyOf(wrong!));
  });

  it("key ตรง = ผ่าน (คืน null) · env มี whitespace รอบ ๆ ก็ trim ให้เทียบได้", () => {
    process.env.DOCVER_API_KEY = "test-key";
    expect(requireDocverApiKey(reqWithKey("test-key"))).toBeNull();
    process.env.DOCVER_API_KEY = "  test-key  ";
    expect(requireDocverApiKey(reqWithKey("test-key"))).toBeNull();
  });
});

describe("requireDocverBearer", () => {
  it("ทุกกรณีพ้นสภาพ (ไม่มี header / ไม่ใช่ Bearer / token เน่า / หมดอายุ / secret ไม่ตั้ง) = 401 ข้อความเดียวกัน", async () => {
    const deniedBodies = new Set<string>();
    const cases: { label: string; secret: string | undefined; authorization: string | null }[] = [
      { label: "ไม่มี Authorization", secret: SECRET, authorization: null },
      { label: "scheme อื่น (Basic)", secret: SECRET, authorization: "Basic dXNlcjpwYXNz" },
      { label: "Bearer ว่างเปล่า", secret: SECRET, authorization: "Bearer " },
      { label: "token เน่า", secret: SECRET, authorization: "Bearer garbage.token.here" },
      {
        label: "token หมดอายุ",
        secret: SECRET,
        authorization: `Bearer ${issueDocverToken(CLAIMS, SECRET, -10)}`,
      },
      {
        label: "เซ็นด้วย secret ผิด",
        secret: SECRET,
        authorization: `Bearer ${issueDocverToken(CLAIMS, "other-secret", 60)}`,
      },
      { label: "secret ไม่ตั้ง (fail closed)", secret: undefined, authorization: null },
      {
        label: "secret ไม่ตั้งแม้จะมี token ถูก",
        secret: undefined,
        authorization: `Bearer ${issueDocverToken(CLAIMS, SECRET, 60)}`,
      },
    ];
    for (const testCase of cases) {
      if (testCase.secret === undefined) delete process.env.DOCVER_TOKEN_SECRET;
      else process.env.DOCVER_TOKEN_SECRET = testCase.secret;
      const auth = requireDocverBearer(reqWithBearer(testCase.authorization));
      expect(auth.ok, testCase.label).toBe(false);
      if (!auth.ok) {
        expect(auth.response.status, testCase.label).toBe(401);
        deniedBodies.add(JSON.stringify(await bodyOf(auth.response)));
      }
    }
    expect(deniedBodies.size).toBe(1); // ข้อความ 401 เดียวกันหมด — ไม่ใช้ endpoint เป็น oracle
  });

  it("Bearer ที่ verify ผ่าน = ได้ claims · คำว่า bearer พิมพ์เล็กก็รับ (case-insensitive)", () => {
    process.env.DOCVER_TOKEN_SECRET = SECRET;
    const token = issueDocverToken(CLAIMS, SECRET, 60);
    const auth = requireDocverBearer(reqWithBearer(`Bearer ${token}`));
    ok(auth);
    expect(auth.claims).toEqual(CLAIMS);
    const lower = requireDocverBearer(reqWithBearer(`bearer ${token}`));
    ok(lower);
    expect(lower.claims).toEqual(CLAIMS);
  });

  it("env มี whitespace รอบ secret ก็ trim แล้ว verify ได้", () => {
    process.env.DOCVER_TOKEN_SECRET = `  ${SECRET}  `;
    const auth = requireDocverBearer(
      reqWithBearer(`Bearer ${issueDocverToken(CLAIMS, SECRET, 60)}`),
    );
    ok(auth);
    expect(auth.claims).toEqual(CLAIMS);
  });
});

describe("parseTokenRequestBody", () => {
  it("ครบทุก field = ได้ claims (trim ค่า) · template ไม่ส่ง = null (fid บังคับ)", () => {
    const full = parseTokenRequestBody({
      userid: " 123 ",
      username: " Sorawit Bholsithi ",
      fid: " 3 ",
      template: " T12 ",
    });
    ok(full);
    expect(full.claims).toEqual({ userid: "123", username: "Sorawit Bholsithi", fid: "3", template: "T12" });

    const minimal = parseTokenRequestBody({ userid: "123", username: "Sorawit", fid: "3" });
    ok(minimal);
    expect(minimal.claims).toEqual({ userid: "123", username: "Sorawit", fid: "3", template: null });
  });

  it("template ส่งมาเป็นช่องว่าง = null (ถือว่าไม่ส่ง)", () => {
    const result = parseTokenRequestBody({ userid: "123", username: "n", fid: "3", template: "   " });
    ok(result);
    expect(result.claims.template).toBeNull();
  });

  it("ไม่ใช่ object (array / string / null) = 400", () => {
    for (const raw of [[], "text", null]) {
      const result = parseTokenRequestBody(raw);
      expect(result.ok).toBe(false);
      if (!result.ok) expect(result.error).toBe("body ต้องเป็น JSON object");
    }
  });

  it("key อื่นนอก allowlist = 400 ไม่รู้จัก field (กัน typo เงียบ ๆ)", () => {
    const result = parseTokenRequestBody({ userid: "1", username: "n", oops: 1 });
    expect(result.ok).toBe(false);
    if (!result.ok) expect(result.error).toContain("oops");
  });

  it("ขาด userid หรือ username / ส่งมาไม่ใช่ string = 400 ข้อความเฉพาะ field", () => {
    for (const raw of [
      { username: "n" },
      { userid: "  ", username: "n" },
      { userid: 123, username: "n" },
      { userid: "1" },
      { userid: "1", username: "" },
    ]) {
      const result = parseTokenRequestBody(raw);
      expect(result.ok).toBe(false);
      if (!result.ok) {
        expect(result.error).toMatch(/ต้องระบุ (userid|username)/);
      }
    }
  });

  it("fid ขาด/null/ว่าง/ไม่ใช่ string (number) หรือ template ไม่ใช่ string = 400", () => {
    const missing = parseTokenRequestBody({ userid: "1", username: "n" });
    expect(missing.ok).toBe(false);
    if (!missing.ok) expect(missing.error).toContain("fid");
    for (const raw of [
      { userid: "1", username: "n", fid: null },
      { userid: "1", username: "n", fid: 3 },
      { userid: "1", username: "n", fid: "" },
      { userid: "1", username: "n", fid: "   " },
      { userid: "1", username: "n", template: 12 },
    ]) {
      expect(parseTokenRequestBody(raw).ok).toBe(false);
    }
  });

  it("ความยาวเกิน cap: userid > 100 / username > 200 / fid > 200 / template > 100 = 400", () => {
    expect(parseTokenRequestBody({ userid: "a".repeat(101), username: "n" }).ok).toBe(false);
    expect(
      parseTokenRequestBody({ userid: "1", username: "a".repeat(201) }).ok,
    ).toBe(false);
    expect(
      parseTokenRequestBody({ userid: "1", username: "n", fid: "a".repeat(201) }).ok,
    ).toBe(false);
    expect(
      parseTokenRequestBody({ userid: "1", username: "n", template: "a".repeat(101) }).ok,
    ).toBe(false);
  });
});