package publicapi_test

import (
	"encoding/json"
	"net/http/httptest"
	"os"
	"testing"

	"git.nianxx.cn/wangxuming/NianAIGC/backend/internal/publicapi"
)

type authErrorFixture struct {
	Status  int    `json:"status"`
	Message string `json:"message"`
}

type authFixture struct {
	Version int    `json:"version"`
	APIKeys string `json:"apiKeys"`
	Clients []struct {
		ID  string `json:"id"`
		Key string `json:"key"`
	} `json:"clients"`
	AuthenticationCases []struct {
		Name     string            `json:"name"`
		Headers  map[string]string `json:"headers"`
		Expected *struct {
			Client struct {
				ID  string `json:"id"`
				Key string `json:"key"`
			} `json:"client"`
			Owner string `json:"owner"`
		} `json:"expected"`
		Error *authErrorFixture `json:"error"`
	} `json:"authenticationCases"`
	OwnerCases []struct {
		ID            string `json:"id"`
		Owner         string `json:"owner"`
		MaxPartLength int    `json:"maxPartLength"`
	} `json:"ownerCases"`
	WorkerCases []struct {
		Name            string            `json:"name"`
		Production      bool              `json:"production"`
		ConfiguredToken string            `json:"configuredToken"`
		Headers         map[string]string `json:"headers"`
		Allowed         bool              `json:"allowed"`
		Error           *authErrorFixture `json:"error"`
	} `json:"workerCases"`
}

func TestParseClientsMatchesSharedContract(t *testing.T) {
	fixture := loadAuthFixture(t)
	clients := publicapi.ParseClients(fixture.APIKeys)
	if len(clients) != len(fixture.Clients) {
		t.Fatalf("len(ParseClients()) = %d, want %d", len(clients), len(fixture.Clients))
	}
	for index, want := range fixture.Clients {
		if clients[index] != (publicapi.PublicClient{ID: want.ID, Key: want.Key}) {
			t.Fatalf("client[%d] = %+v, want %+v", index, clients[index], want)
		}
	}
}

func TestAuthenticateMatchesSharedContract(t *testing.T) {
	fixture := loadAuthFixture(t)
	authenticator := publicapi.NewAuthenticator(publicapi.Config{APIKeys: fixture.APIKeys})
	for _, testCase := range fixture.AuthenticationCases {
		t.Run(testCase.Name, func(t *testing.T) {
			request := httptest.NewRequest("GET", "/api/v1/generations", nil)
			for name, value := range testCase.Headers {
				request.Header.Set(name, value)
			}
			client, owner, err := authenticator.Authenticate(request)
			if testCase.Error != nil {
				assertAuthError(t, err, *testCase.Error)
				return
			}
			if err != nil {
				t.Fatalf("Authenticate() error = %v", err)
			}
			wantClient := publicapi.PublicClient{ID: testCase.Expected.Client.ID, Key: testCase.Expected.Client.Key}
			if client != wantClient || owner != testCase.Expected.Owner {
				t.Fatalf("Authenticate() = (%+v, %q), want (%+v, %q)", client, owner, wantClient, testCase.Expected.Owner)
			}
		})
	}
}

func TestOwnerIDMatchesSharedContract(t *testing.T) {
	fixture := loadAuthFixture(t)
	for _, testCase := range fixture.OwnerCases {
		t.Run(testCase.ID, func(t *testing.T) {
			owner := publicapi.OwnerID(testCase.ID)
			if owner != testCase.Owner {
				t.Fatalf("OwnerID(%q) = %q, want %q", testCase.ID, owner, testCase.Owner)
			}
			if testCase.MaxPartLength > 0 && len(owner)-len("api:") != testCase.MaxPartLength {
				t.Fatalf("owner part length = %d, want %d", len(owner)-len("api:"), testCase.MaxPartLength)
			}
		})
	}
}

func TestAssertInternalWorkerMatchesSharedContract(t *testing.T) {
	fixture := loadAuthFixture(t)
	for _, testCase := range fixture.WorkerCases {
		t.Run(testCase.Name, func(t *testing.T) {
			authenticator := publicapi.NewAuthenticator(publicapi.Config{
				InternalWorkerToken: testCase.ConfiguredToken,
				Production:          testCase.Production,
			})
			request := httptest.NewRequest("POST", "/api/internal/worker/tick", nil)
			for name, value := range testCase.Headers {
				request.Header.Set(name, value)
			}
			err := authenticator.AssertInternalWorker(request)
			if testCase.Error != nil {
				assertAuthError(t, err, *testCase.Error)
				return
			}
			if err != nil {
				t.Fatalf("AssertInternalWorker() error = %v", err)
			}
		})
	}
}

func TestAuthenticatorUsesOnlyInjectedConfig(t *testing.T) {
	t.Setenv("ZHINIAN_API_KEYS", "environment:must-not-be-read")
	t.Setenv("ZHINIAN_INTERNAL_WORKER_TOKEN", "environment-worker-token")
	t.Setenv("NODE_ENV", "production")

	authenticator := publicapi.NewAuthenticator(publicapi.Config{})
	request := httptest.NewRequest("GET", "/", nil)
	request.Header.Set("authorization", "Bearer must-not-be-read")
	_, _, err := authenticator.Authenticate(request)
	assertAuthError(t, err, authErrorFixture{Status: 401, Message: "Invalid API key."})
	if err := authenticator.AssertInternalWorker(httptest.NewRequest("POST", "/", nil)); err != nil {
		t.Fatalf("development bypass with injected zero config error = %v", err)
	}
}

func assertAuthError(t *testing.T, err error, want authErrorFixture) {
	t.Helper()
	if err == nil {
		t.Fatal("error = nil, want typed authentication error")
	}
	authError, ok := err.(*publicapi.AuthError)
	if !ok {
		t.Fatalf("error type = %T, want *publicapi.AuthError", err)
	}
	if authError.Status != want.Status || authError.Message != want.Message || authError.Error() != want.Message {
		t.Fatalf("error = %+v, want status=%d message=%q", authError, want.Status, want.Message)
	}
}

func loadAuthFixture(t *testing.T) authFixture {
	t.Helper()
	data, err := os.ReadFile("../../../contracts/auth/public-api-auth-v1.json")
	if err != nil {
		t.Fatalf("read public API auth fixture: %v", err)
	}
	var fixture authFixture
	if err := json.Unmarshal(data, &fixture); err != nil {
		t.Fatalf("decode public API auth fixture: %v", err)
	}
	if fixture.Version != 1 {
		t.Fatalf("fixture version = %d, want 1", fixture.Version)
	}
	return fixture
}