package api

import (
	"bytes"
	"fmt"
	"mime/multipart"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"dns.froth.zone/pomme/internal"
	"dns.froth.zone/pomme/internal/db"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/jwtauth/v5"
	"github.com/stretchr/testify/assert"
	"golang.org/x/crypto/bcrypt"
	"gorm.io/gorm"
)

type accountTest struct {
	username string
	password string
	token    string
	url      string
}

func makeTestToken(username string) (tokenString string, err error) {
	claim := map[string]any{"username": username, "admin": false}

	jwtauth.SetExpiry(claim, time.Now().Add(time.Minute))

	if _, tokenString, err = tokenAuth.Encode(claim); err == nil {
		return
	}

	return "", fmt.Errorf("unable to generate JWT: %w", err)
}

func TestAPI(t *testing.T) {
	config, err := internal.ReadConfig()
	if err != nil {
		assert.NotNil(t, err)
	}

	pomme := chi.NewRouter()

	pomme.Mount("/api", API())

	s := &http.Server{
		ReadTimeout:  3 * time.Second,
		WriteTimeout: 15 * time.Second,
		Addr:         ":" + config.Port,
		Handler:      pomme,
	}

	ts := httptest.NewUnstartedServer(pomme)
	ts.Config = s
	ts.Start()

	defer ts.Close()

	tester := Init(ts.URL)
	// test mode
	mode = "test"
	db, err, _ := db.InitDb(config.DB, mode)
	assert.Nil(t, err)

	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(tester.password), bcrypt.DefaultCost)
	assert.Nil(t, err)

	db.Create(&internal.User{Username: tester.username, HashedPassword: string(hashedPassword)})

	tester.TestOpenRoutes(t)
	tester.TestProtectedRoutes(t)
	tester.TestRateLimit(t)
	tester.CleanUp(db)
}

func Init(url string) accountTest {
	user := autoUname()

	user += "-testUser"

	token, err := makeTestToken(user)
	if err != nil {
		return accountTest{}
	}

	test := accountTest{
		username: user,
		password: "merde",
		url:      url,
		token:    token,
	}

	return test
}

type expectedValues struct {
	response int
}

func (a *accountTest) TestOpenRoutes(t *testing.T) {
	testCases := []struct {
		name     string
		route    string
		token    string
		password string
		username string
		expected expectedValues
	}{
		{
			name:     "Should fail to login with bad username",
			route:    "login",
			username: "a.username",
			password: a.password,
			expected: expectedValues{
				response: http.StatusUnauthorized,
			},
		},
		{
			name:     "Should fail to login with bad password",
			route:    "login",
			username: a.username,
			password: "a.password",
			expected: expectedValues{
				response: http.StatusUnauthorized,
			},
		},
		{
			name:     "Should fail to login with bad password or username",
			route:    "login",
			username: "apple",
			password: "a.password",
			expected: expectedValues{
				response: http.StatusUnauthorized,
			},
		},
		{
			name:  "Should fail to login with empty form",
			route: "login",
			expected: expectedValues{
				response: http.StatusInternalServerError,
			},
		},
		{
			name:     "Should login successfully",
			route:    "login",
			username: a.username,
			password: a.password,
			expected: expectedValues{
				response: http.StatusOK,
			},
		},
		{
			name:  "Should fail to create account with empty form",
			route: "create",
			expected: expectedValues{
				response: http.StatusInternalServerError,
			},
		},
		{
			name:     "Should create account with empty username",
			route:    "create",
			password: "asdf",
			expected: expectedValues{
				response: http.StatusCreated,
			},
		},
		{
			name:  "Should fail to create account with empty password",
			route: "create",
			expected: expectedValues{
				response: http.StatusInternalServerError,
			},
		},
		{
			name:     "Should log out successfully",
			route:    "logout",
			username: a.username,
			expected: expectedValues{
				response: http.StatusOK,
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			client := http.Client{}

			form := url.Values{}

			form.Add("username", tc.username)

			form.Add("password", tc.password)

			if req, err := http.NewRequest(http.MethodPost, a.url+`/api/`+tc.route, strings.NewReader(form.Encode())); err == nil {
				req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

				resp, err := client.Do(req)
				if err != nil {
					assert.NotNil(t, err)
				}

				assert.Equal(t, tc.expected.response, resp.StatusCode)
			}
		})
	}
}

func (a *accountTest) TestRateLimit(t *testing.T) {
	testCases := []struct {
		name     string
		route    string
		password string
		username string
		expected expectedValues
	}{
		{
			name:  "Should rate limit open routes",
			route: "login",
			expected: expectedValues{
				response: http.StatusTooManyRequests,
			},
		},
		{
			name:  "Should rate limit private routes",
			route: "upload",
			expected: expectedValues{
				response: http.StatusTooManyRequests,
			},
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			client := http.Client{}

			form := url.Values{}

			if req, err := http.NewRequest(http.MethodPost, a.url+`/api/`+tc.route, strings.NewReader(form.Encode())); err == nil {
				req.Header.Add("Content-Type", "application/x-www-form-urlencoded")

				for i := 0; i < 100; i++ {
					resp, err := client.Do(req)
					if err != nil {
						assert.NotNil(t, err)
					}

					if resp.StatusCode == tc.expected.response {
						assert.Equal(t, tc.expected.response, resp.StatusCode)
					}
				}
			}
		})
	}
}

func (a *accountTest) TestProtectedRoutes(t *testing.T) {
	testCases := []struct {
		name         string
		contentType  string
		route        string
		fileContents []byte
		expected     expectedValues
	}{
		{
			name:        "Should fail to upload an empty file",
			contentType: "audio/aac",
			route:       "upload",
			expected: expectedValues{
				response: http.StatusInternalServerError,
			},
		},
		{
			name:         "Should upload a valid file",
			contentType:  "multipart/form-data",
			fileContents: []byte{},
			route:        "upload",
			expected: expectedValues{
				response: http.StatusCreated,
			},
		},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			var (
				f   *os.File
				err error
				buf = new(bytes.Buffer)
				w   = multipart.NewWriter(buf)
			)

			f, err = os.CreateTemp(".", "zonefile")
			if err != nil {
				assert.NotNil(t, err)
			}

			if tc.name == "Should upload a valid file" {
				if err = os.WriteFile(f.Name(), zonebytes, 0o600); err != nil {
					assert.NotNil(t, err)
				}
			}

			defer os.Remove(f.Name()) //nolint: errcheck

			part, err := w.CreateFormFile("file", filepath.Base(f.Name()))
			if err != nil {
				assert.NotNil(t, err)
			}

			b, err := os.ReadFile(f.Name())
			if err != nil {
				assert.NotNil(t, err)
			}

			_, err = part.Write(b)
			if err != nil {
				assert.NotNil(t, err)
			}

			err = w.Close()
			if err != nil {
				assert.NotNil(t, err)
			}
			client := http.Client{}
			if req, err := http.NewRequest(http.MethodPost, a.url+`/api/`+tc.route, buf); err == nil {
				if tc.name == "Should fail to upload an empty file" {
					req.Header.Add("Content-Type", tc.contentType)
				} else {
					req.Header.Add("Content-Type", w.FormDataContentType())
				}

				req.Header.Add("Authorization", `Bearer:`+a.token)

				resp, err := client.Do(req)
				if err != nil {
					assert.NotNil(t, err)
				}
				assert.Equal(t, tc.expected.response, resp.StatusCode)
			}
		})
	}
}

func (a *accountTest) CleanUp(db *gorm.DB) {
	if err := os.Remove("pomme-test.sqlite"); err != nil {
		l := newResponder(Response[any]{
			Message: "unable to clean up test DB",
			Err:     err.Error(),
		})
		l.writeLogEntry()
	}
}