local createLibTest = require('/apis/libtest');
local createAiHelloWorld = require('/apis/libaihelloworld');

local testlib = createLibTest({ ... });

local function fakeSettings(initial)
  local values = initial or {};
  local saveCount = 0;
  return {
    get = function(key) return values[key]; end,
    set = function(key, value) values[key] = value; end,
    unset = function(key) values[key] = nil; end,
    save = function() saveCount = saveCount + 1; end,
    values = values,
    saveCount = function() return saveCount; end,
  };
end

local function response(code, body)
  return {
    getResponseCode = function() return code; end,
    readAll = function() return body; end,
    close = function() end,
  };
end

-- postResults: list of responses returned in order for each POST call.
-- getResults: list of responses returned in order for each GET call.
local function fakeHttp(postResults, getResults)
  postResults = postResults or {};
  getResults = getResults or {};
  local postCalls = {};
  local getCalls = {};
  local postIdx = 0;
  local getIdx = 0;
  return {
    post = function(url, body, headers)
      postCalls[#postCalls + 1] = { url = url, body = body, headers = headers };
      postIdx = postIdx + 1;
      local r = postResults[postIdx];
      if type(r) == 'function' then return r(url, body, headers); end
      return r;
    end,
    get = function(url, headers)
      getCalls[#getCalls + 1] = { url = url, headers = headers };
      getIdx = getIdx + 1;
      local r = getResults[getIdx];
      if type(r) == 'function' then return r(url, headers); end
      return r;
    end,
    postCalls = postCalls,
    getCalls = getCalls,
  };
end

local function httpError(code, body)
  return function()
    return nil, 'HTTP response code ' .. tostring(code), response(code, body);
  end;
end

local function sessionResp(id)
  return response(200, textutils.serializeJSON({ id = id, title = 'cc-helloworld' }));
end

local function messageResp(reply)
  return response(200, textutils.serializeJSON({
    info = {},
    parts = { { type = 'text', text = reply } },
  }));
end

-- base64 --

testlib.test('base64encode encodes simple ascii', function()
  -- "Man" -> "TWFu" is the canonical base64 test vector; tested indirectly via Authorization header
  local httpStub = fakeHttp(
    { sessionResp('ses_1'), messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  settingsStub.values['opencc.password'] = 'pass';
  settingsStub.values['opencc.username'] = 'user';
  createAiHelloWorld({ http = httpStub, settings = settingsStub }).askHello();
  local auth = httpStub.postCalls[1].headers['Authorization'];
  -- base64('user:pass') = 'dXNlcjpwYXNz'
  testlib.assertEquals(auth, 'Basic dXNlcjpwYXNz');
end);

testlib.test('base64encode handles padding with one remainder byte', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_1'), messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  settingsStub.values['opencc.password'] = 'x';
  settingsStub.values['opencc.username'] = 'a';
  createAiHelloWorld({ http = httpStub, settings = settingsStub }).askHello();
  -- base64('a:x') = 'YTp4'
  testlib.assertEquals(httpStub.postCalls[1].headers['Authorization'], 'Basic YTp4');
end);

-- listSessions --

testlib.test('listSessions returns parsed session list', function()
  local sessions = { { id = 'ses_1', title = 'hello' }, { id = 'ses_2', title = 'world' } };
  local httpStub = fakeHttp({}, { response(200, textutils.serializeJSON(sessions)) });
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, result = ai.listSessions();

  testlib.assertTrue(ok, tostring(result));
  testlib.assertEquals(#result, 2);
  testlib.assertEquals(result[1].id, 'ses_1');
end);

testlib.test('listSessions fails when server_url missing', function()
  local httpStub = fakeHttp({}, {});
  local ai = createAiHelloWorld({ http = httpStub, settings = fakeSettings() });

  local ok, err = ai.listSessions();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'opencc.server_url', 1, true) ~= nil);
  testlib.assertEquals(#httpStub.getCalls, 0);
end);

testlib.test('listSessions fails when server unreachable', function()
  local httpStub = fakeHttp({}, { nil });
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.listSessions();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'injoignable', 1, true) ~= nil);
end);

testlib.test('listSessions maps HTTP error response codes', function()
  local httpStub = fakeHttp({}, { httpError(401, '{}') });
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.listSessions();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'HTTP 401', 1, true) ~= nil);
end);

-- askHello --

testlib.test('askHello creates session then sends message when no session_id', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_new'), messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host:4096' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, result = ai.askHello();

  testlib.assertTrue(ok, tostring(result));
  testlib.assertEquals(result.reply, 'pong');
  testlib.assertEquals(result.sessionId, 'ses_new');
  testlib.assertEquals(#httpStub.postCalls, 2);
  testlib.assertTrue(string.find(httpStub.postCalls[1].url, '/session', 1, true) ~= nil);
  testlib.assertTrue(string.find(httpStub.postCalls[2].url, '/session/ses_new/message', 1, true) ~= nil);
end);

testlib.test('askHello saves new session_id to settings', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_abc'), messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  ai.askHello();

  testlib.assertEquals(settingsStub.values['opencc.session_id'], 'ses_abc');
  testlib.assertEquals(settingsStub.saveCount(), 1);
end);

testlib.test('askHello reuses existing session_id without creating a new session', function()
  local httpStub = fakeHttp(
    { messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({
    ['opencc.server_url'] = 'http://host',
    ['opencc.session_id'] = 'ses_existing',
  });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok = ai.askHello();

  testlib.assertTrue(ok);
  testlib.assertEquals(#httpStub.postCalls, 1);
  testlib.assertTrue(string.find(httpStub.postCalls[1].url, '/session/ses_existing/message', 1, true) ~= nil);
end);

testlib.test('askHello sends correct message body', function()
  local httpStub = fakeHttp(
    { messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({
    ['opencc.server_url'] = 'http://host',
    ['opencc.session_id'] = 'ses_1',
  });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub, prompt = 'my prompt' });

  ai.askHello();

  local body = textutils.unserializeJSON(httpStub.postCalls[1].body);
  testlib.assertEquals(#body.parts, 1);
  testlib.assertEquals(body.parts[1].type, 'text');
  testlib.assertEquals(body.parts[1].text, 'my prompt');
end);

testlib.test('askHello concatenates multiple text parts', function()
  local httpStub = fakeHttp(
    { response(200, textutils.serializeJSON({
        info = {},
        parts = {
          { type = 'step-start' },
          { type = 'text', text = 'hello ' },
          { type = 'tool-call' },
          { type = 'text', text = 'world' },
        },
      })) },
    {}
  );
  local settingsStub = fakeSettings({
    ['opencc.server_url'] = 'http://host',
    ['opencc.session_id'] = 'ses_1',
  });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, result = ai.askHello();

  testlib.assertTrue(ok, tostring(result));
  testlib.assertEquals(result.reply, 'hello world');
end);

testlib.test('askHello fails with missing server_url', function()
  local httpStub = fakeHttp({}, {});
  local ai = createAiHelloWorld({ http = httpStub, settings = fakeSettings() });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'opencc.server_url', 1, true) ~= nil);
  testlib.assertEquals(#httpStub.postCalls, 0);
end);

testlib.test('askHello fails when server unreachable on session create', function()
  local httpStub = fakeHttp({ nil }, {});
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'injoignable', 1, true) ~= nil);
end);

testlib.test('askHello fails when server unreachable on message send', function()
  local httpStub = fakeHttp({ sessionResp('ses_1'), nil }, {});
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'injoignable', 1, true) ~= nil);
end);

testlib.test('askHello maps 401 on message send', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_1'), response(401, '{}') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'HTTP 401', 1, true) ~= nil);
end);

testlib.test('askHello maps HTTP error response on message send', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_1'), httpError(401, '{}') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, 'HTTP 401', 1, true) ~= nil);
end);

testlib.test('askHello on 404 clears session_id and suggests --new', function()
  local httpStub = fakeHttp(
    { response(404, '{}') },
    {}
  );
  local settingsStub = fakeSettings({
    ['opencc.server_url'] = 'http://host',
    ['opencc.session_id'] = 'ses_stale',
  });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, '--new', 1, true) ~= nil);
  testlib.assertEquals(settingsStub.values['opencc.session_id'], nil);
end);

testlib.test('askHello on HTTP error 404 clears session_id', function()
  local httpStub = fakeHttp(
    { httpError(404, '{}') },
    {}
  );
  local settingsStub = fakeSettings({
    ['opencc.server_url'] = 'http://host',
    ['opencc.session_id'] = 'ses_stale',
  });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  local ok, err = ai.askHello();

  testlib.assertTrue(not ok);
  testlib.assertTrue(string.find(err, '--new', 1, true) ~= nil);
  testlib.assertEquals(settingsStub.values['opencc.session_id'], nil);
end);

testlib.test('askHello omits Authorization header when no password', function()
  local httpStub = fakeHttp(
    { sessionResp('ses_1'), messageResp('pong') },
    {}
  );
  local settingsStub = fakeSettings({ ['opencc.server_url'] = 'http://host' });
  local ai = createAiHelloWorld({ http = httpStub, settings = settingsStub });

  ai.askHello();

  testlib.assertEquals(httpStub.postCalls[1].headers['Authorization'], nil);
end);

-- clearSession --

testlib.test('clearSession unsets persisted session id', function()
  local settingsStub = fakeSettings({ ['opencc.session_id'] = 'ses_old' });
  local ai = createAiHelloWorld({ http = fakeHttp({}, {}), settings = settingsStub });

  ai.clearSession();

  testlib.assertEquals(settingsStub.values['opencc.session_id'], nil);
  testlib.assertEquals(settingsStub.saveCount(), 1);
end);

testlib.run();