package ibd

import (
	"bytes"
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/ansg191/ibd-trader-backend/internal/database"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

const apiKey = "test-api-key-123"

func newServer(t *testing.T, handler http.Handler) *httptest.Server {
	t.Helper()

	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		r.Close = true
		defer r.Body.Close()
		req := reconstructReq(t, r)

		rw := newResponseWriter()
		handler.ServeHTTP(rw, req)
		require.NoError(t, rw.Done(w))
	}))
}

func reconstructReq(t *testing.T, r *http.Request) *http.Request {
	t.Helper()

	params := r.URL.Query()
	require.Equal(t, apiKey, params.Get("key"))

	// Reconstruct the request from the query params
	var key string
	var url string
	headers := make(http.Header)
	for k, v := range params {
		switch k {
		case "key":
			key = v[0]
		case "url":
			url = v[0]
		default:
			if strings.HasPrefix(k, "headers") {
				var name string
				// Get index of first [
				i := strings.Index(k, "[")
				if i == -1 {
					t.Fatalf("invalid header key: %s", k)
				}
				// Get index of first ]
				j := strings.Index(k, "]")
				if j == -1 {
					t.Fatalf("invalid header key: %s", k)
				}

				// Get the header name
				name = k[i+1 : j]
				headers.Set(name, v[0])
			}
		}
	}
	require.Equal(t, apiKey, key)
	require.NotEmpty(t, url)

	req, err := http.NewRequestWithContext(r.Context(), r.Method, url, r.Body)
	require.NoError(t, err)
	req.Header = headers

	return req
}

type responsewriter struct {
	ret     ScraperResponse
	body    bytes.Buffer
	headers http.Header
}

func newResponseWriter() *responsewriter {
	return &responsewriter{
		headers: make(http.Header),
	}
}

func (w *responsewriter) Header() http.Header {
	return w.headers
}

func (w *responsewriter) Write(bytes []byte) (int, error) {
	if w.ret.Result.StatusCode == 0 {
		w.ret.Result.StatusCode = http.StatusOK
	}
	return w.body.Write(bytes)
}

func (w *responsewriter) WriteHeader(statusCode int) {
	w.ret.Result.StatusCode = statusCode
}

func (w *responsewriter) Done(rw http.ResponseWriter) error {
	w.ret.Result.Content = w.body.String()

	w.ret.Result.ResponseHeaders = make(map[string]string)
	for k, v := range w.headers {
		if k == "Set-Cookie" {
			continue
		}
		w.ret.Result.ResponseHeaders[k] = v[0]
	}

	req := http.Response{Header: w.headers}
	w.ret.Result.Cookies = make([]ScraperCookie, 0)
	for _, c := range req.Cookies() {
		var cookie ScraperCookie
		cookie.FromHTTPCookie(c)
		w.ret.Result.Cookies = append(w.ret.Result.Cookies, cookie)
	}

	rw.WriteHeader(http.StatusOK)
	return json.NewEncoder(rw).Encode(w.ret)
}

func TestClient_getCookie(t *testing.T) {
	t.Parallel()

	t.Run("no cookies", func(t *testing.T) {
		t.Parallel()

		client, err := NewClient(
			http.DefaultClient,
			apiKey,
			new(emptyCookieSourceStub),
			"",
		)
		require.NoError(t, err)

		_, _, err = client.getCookie(context.Background(), nil)
		assert.ErrorIs(t, err, ErrNoAvailableCookies)
	})

	t.Run("no cookies by subject", func(t *testing.T) {
		t.Parallel()

		client, err := NewClient(
			http.DefaultClient,
			apiKey,
			new(emptyCookieSourceStub),
			"",
		)
		require.NoError(t, err)

		subject := "test"
		_, _, err = client.getCookie(context.Background(), &subject)
		assert.ErrorIs(t, err, ErrNoAvailableCookies)
	})

	t.Run("get any cookie", func(t *testing.T) {
		t.Parallel()

		client, err := NewClient(
			http.DefaultClient,
			apiKey,
			new(cookieSourceStub),
			"",
		)
		require.NoError(t, err)

		id, cookie, err := client.getCookie(context.Background(), nil)
		require.NoError(t, err)
		assert.Equal(t, uint(42), id)
		assert.Equal(t, cookieName, cookie.Name)
		assert.Equal(t, "test-token", cookie.Value)
		assert.Equal(t, "/", cookie.Path)
		assert.Equal(t, time.Unix(0, 0), cookie.Expires)
		assert.Equal(t, "investors.com", cookie.Domain)
	})

	t.Run("get cookie by subject", func(t *testing.T) {
		t.Parallel()

		client, err := NewClient(
			http.DefaultClient,
			apiKey,
			new(cookieSourceStub),
			"",
		)
		require.NoError(t, err)

		subject := "test"
		id, cookie, err := client.getCookie(context.Background(), &subject)
		require.NoError(t, err)
		assert.Equal(t, uint(42), id)
		assert.Equal(t, cookieName, cookie.Name)
		assert.Equal(t, "test-token", cookie.Value)
		assert.Equal(t, "/", cookie.Path)
		assert.Equal(t, time.Unix(0, 0), cookie.Expires)
		assert.Equal(t, "investors.com", cookie.Domain)
	})
}

type emptyCookieSourceStub struct{}

func (c *emptyCookieSourceStub) GetAnyCookie(_ context.Context) (*database.IBDCookie, error) {
	return nil, nil
}

func (c *emptyCookieSourceStub) GetCookies(_ context.Context, _ string, _ bool) ([]database.IBDCookie, error) {
	return nil, nil
}

func (c *emptyCookieSourceStub) ReportCookieFailure(_ context.Context, _ uint) error {
	return nil
}

var testCookie = database.IBDCookie{
	ID:     42,
	Token:  "test-token",
	Expiry: time.Unix(0, 0),
}

type cookieSourceStub struct{}

func (c *cookieSourceStub) GetAnyCookie(_ context.Context) (*database.IBDCookie, error) {
	return &testCookie, nil
}

func (c *cookieSourceStub) GetCookies(_ context.Context, _ string, _ bool) ([]database.IBDCookie, error) {
	return []database.IBDCookie{testCookie}, nil
}

func (c *cookieSourceStub) ReportCookieFailure(_ context.Context, _ uint) error {
	return nil
}