package web

import (
	"bytes"
	"encoding/json"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"

	"gitgud.io/mike/mpv-manager/pkg/config"
)

func TestHandleConfigApplyAPIValidatesAllFieldsBeforeWriting(t *testing.T) {
	home := t.TempDir()
	t.Setenv("HOME", home)
	t.Setenv("USERPROFILE", home)
	t.Setenv("APPDATA", home)
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, ".config"))

	configPath := config.GetConfigPath()
	if err := os.MkdirAll(filepath.Dir(configPath), 0o755); err != nil {
		t.Fatal(err)
	}
	original := []byte("alang=de\nslang=de\n")
	if err := os.WriteFile(configPath, original, 0o644); err != nil {
		t.Fatal(err)
	}

	// Audio language is valid and appears first in the apply workflow. PNG
	// compression is intentionally invalid and appears much later.
	body := []byte(`{"audio_language":"en","screenshot_png_compression":"10"}`)
	req := httptest.NewRequest(http.MethodPost, "/api/config/apply", bytes.NewReader(body))
	recorder := httptest.NewRecorder()
	server := &Server{}
	server.handleConfigApplyAPI(recorder, req)

	if recorder.Code != http.StatusBadRequest {
		t.Fatalf("status = %d, want %d; body=%s", recorder.Code, http.StatusBadRequest, recorder.Body.String())
	}
	after, err := os.ReadFile(configPath)
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(after, original) {
		t.Fatalf("invalid later field partially changed mpv.conf:\n%s", after)
	}
}

func TestConfigSettingsApplyRetainsScalarCommasAndProfileScope(t *testing.T) {
	setupSandboxedConfigHome(t)
	path := config.GetConfigPath()
	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0755))
	original := "hwdec=auto\nhwdec=nvdec-copy,auto\nalang=en,fr\nscreenshot-template=\"shot,%n\"\nscreenshot-directory=\"Pictures, shots\"\nscreenshot-avif-opts=crf=20,speed=6\n[special]\nhwdec=no\nscreenshot-avif-opts=crf=40,speed=8\n"
	require.NoError(t, os.WriteFile(path, []byte(original), 0600))
	server := &Server{}
	settings := server.getConfigSettings()
	assert.Equal(t, "nvdec-copy,auto", settings.HardwareAccel)
	assert.Equal(t, []string{"en", "fr"}, settings.AudioLanguages)
	assert.Equal(t, "crf=20,speed=6", settings.ScreenshotAvifOpts)
	assert.Equal(t, "Pictures, shots", settings.ScreenshotDirectory)
	assert.Equal(t, "shot,%n", settings.ScreenshotTemplate)

	get := httptest.NewRecorder()
	server.handleConfigSettingsAPI(get, httptest.NewRequest(http.MethodGet, "/api/config/settings", nil))
	var values map[string]string
	require.NoError(t, json.Unmarshal(get.Body.Bytes(), &values))
	assert.Equal(t, settings.HardwareAccel, values["hardware_acceleration"])
	// The form sends the displayed scalar fields back unchanged on Apply.
	body, err := json.Marshal(map[string]string{
		"hardware_acceleration": settings.HardwareAccel,
		"screenshot_avif_opts":  settings.ScreenshotAvifOpts,
		"screenshot_directory":  settings.ScreenshotDirectory,
		"screenshot_template":   settings.ScreenshotTemplate,
	})
	require.NoError(t, err)
	result := httptest.NewRecorder()
	server.handleConfigApplyAPI(result, httptest.NewRequest(http.MethodPost, "/api/config/apply", bytes.NewReader(body)))
	require.Equal(t, http.StatusOK, result.Code, result.Body.String())
	after := server.getConfigSettings()
	assert.Equal(t, settings.ScreenshotAvifOpts, after.ScreenshotAvifOpts)
	assert.Equal(t, settings.ScreenshotDirectory, after.ScreenshotDirectory)
	assert.Equal(t, settings.ScreenshotTemplate, after.ScreenshotTemplate)
	assert.Equal(t, settings.HardwareAccel, after.HardwareAccel)
	content, err := os.ReadFile(path)
	require.NoError(t, err)
	assert.Contains(t, string(content), "[special]\nhwdec=no\nscreenshot-avif-opts=crf=40,speed=8\n")
	if runtime.GOOS != "windows" {
		info, err := os.Stat(path)
		require.NoError(t, err)
		assert.Equal(t, os.FileMode(0600), info.Mode().Perm())
	}
}

func TestConfigApplyDistinguishesClearFromOmittedFields(t *testing.T) {
	setupSandboxedConfigHome(t)
	path := config.GetConfigPath()
	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
	original := "# preserved\nprofile=cinema\nvo=libmpv\nscale=ewa_lanczos\nscreenshot-directory=/tmp/old # directory note\nscreenshot-template=custom-%n\nscreenshot-avif-opts=crf=20,speed=6\n[cinema]\nscreenshot-directory=/tmp/profile\nscreenshot-template=profile-%n\n"
	require.NoError(t, os.WriteFile(path, []byte(original), 0600))
	server := &Server{}
	result := httptest.NewRecorder()
	server.handleConfigApplyAPI(result, httptest.NewRequest(http.MethodPost, "/api/config/apply", strings.NewReader(`{"screenshot_directory":"","screenshot_template":"","screenshot_avif_opts":""}`)))
	require.Equal(t, http.StatusOK, result.Code, result.Body.String())
	content, err := os.ReadFile(path)
	require.NoError(t, err)
	assert.Equal(t, "# preserved\nprofile=cinema\nvo=libmpv\nscale=ewa_lanczos\n# directory note\n[cinema]\nscreenshot-directory=/tmp/profile\nscreenshot-template=profile-%n\n", string(content))
	// Omitted and JSON-null fields preserve their current state byte for byte.
	for _, body := range []string{`{}`, `{"profile":null,"video_output_driver":null}`} {
		result = httptest.NewRecorder()
		server.handleConfigApplyAPI(result, httptest.NewRequest(http.MethodPost, "/api/config/apply", strings.NewReader(body)))
		require.Equal(t, http.StatusOK, result.Code, result.Body.String())
		after, err := os.ReadFile(path)
		require.NoError(t, err)
		assert.Equal(t, content, after)
	}
}

func TestConfigApplyExplicitEmptyLanguageListsRemainEmpty(t *testing.T) {
	setupSandboxedConfigHome(t)
	path := config.GetConfigPath()
	require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
	require.NoError(t, os.WriteFile(path, []byte("alang=en,fr\nslang=en\n"), 0600))
	result := httptest.NewRecorder()
	(&Server{}).handleConfigApplyAPI(result, httptest.NewRequest(http.MethodPost, "/api/config/apply", strings.NewReader(`{"audio_language":"","subtitle_language":""}`)))
	require.Equal(t, http.StatusOK, result.Code, result.Body.String())
	content, err := os.ReadFile(path)
	require.NoError(t, err)
	assert.Equal(t, "alang=\nslang=\n", string(content))
}