package web

import (
	"bufio"
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"sync"
	"testing"

	"gitgud.io/mike/mpv-manager/pkg/config"
	"gitgud.io/mike/mpv-manager/pkg/installer"
	"gitgud.io/mike/mpv-manager/pkg/platform"
	"github.com/stretchr/testify/require"
)

// TestBrowserFixture is a development-only stdin-controlled server for real
// browser tests. It has no fixture HTTP endpoints and cannot ship in the app.
func TestBrowserFixture(t *testing.T) {
	if os.Getenv("MPV_MANAGER_BROWSER_FIXTURE") != "1" {
		t.Skip("started by npm run test:browser")
	}
	root := t.TempDir()
	for _, key := range []string{"HOME", "USERPROFILE", "APPDATA", "LOCALAPPDATA", "XDG_CONFIG_HOME"} {
		t.Setenv(key, root)
	}
	cfg, err := config.Reload()
	require.NoError(t, err)
	p := &platform.Platform{OSType: platform.OSType(runtime.GOOS), Arch: runtime.GOARCH, GPUInfo: &platform.GPUInfo{}}
	inst := installer.NewInstaller(installer.ReleaseInfo{}, root)
	server := NewServer(p, cfg, inst, nil)
	var refreshMu sync.Mutex
	refreshVersion := "9.9.9"
	refreshFails := false
	originalFetch := fetchReleaseInfo
	fetchReleaseInfo = func(ctx context.Context) (*installer.ReleaseInfo, error) {
		refreshMu.Lock()
		defer refreshMu.Unlock()
		if err := ctx.Err(); err != nil {
			return nil, err
		}
		if refreshFails {
			return nil, fmt.Errorf("fixture signature rejected")
		}
		return &installer.ReleaseInfo{Version: refreshVersion}, nil
	}
	t.Cleanup(func() { fetchReleaseInfo = originalFetch })

	address, serving, err := server.Start("127.0.0.1:0")
	require.NoError(t, err)
	defer func() { require.NoError(t, server.Shutdown()); require.NoError(t, <-serving) }()
	respond := func(data any) {
		encoded, err := json.Marshal(data)
		require.NoError(t, err)
		fmt.Printf("BROWSER_FIXTURE %s\n", encoded)
	}
	respond(map[string]any{"url": "http://" + address})
	type command struct {
		ID      int    `json:"id"`
		Version string `json:"version"`
		Fail    bool   `json:"fail"`
		Action  string `json:"action"`
		JobID   string `json:"jobId"`
		Lines   int    `json:"lines"`
		Content string `json:"content"`
		JobType string `json:"jobType"`
		AppID   string `json:"appId"`
	}
	workers := map[string]chan string{}
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		var cmd command
		require.NoError(t, json.Unmarshal(scanner.Bytes(), &cmd))
		reply := map[string]any{"id": cmd.ID}
		switch cmd.Action {
		case "windows-app-cards":
			var html bytes.Buffer
			windows := &platform.Platform{OSType: platform.Windows, Arch: "amd64"}
			for _, id := range []string{"default-mpv", "custom-mpv"} {
				app := config.InstalledApp{ID: id, AppName: "MPV", InstallMethod: "mpv-binary", InstallPath: `C:\QA\` + id, Managed: true}
				group := AppGroupInfo{App: app, AppName: "MPV", InstallMethod: app.InstallMethod, Managed: true}
				require.NoError(t, server.templates.ExecuteTemplate(&html, "app-card", createAppCardData(group, windows)))
			}
			reply["html"] = html.String()
		case "release":
			refreshMu.Lock()
			refreshVersion, refreshFails = cmd.Version, cmd.Fail
			refreshMu.Unlock()

		case "config":
			path := config.GetConfigPath()
			require.NoError(t, os.MkdirAll(filepath.Dir(path), 0700))
			require.NoError(t, os.WriteFile(path, []byte(cmd.Content), 0600))
		case "read-config":
			content, err := os.ReadFile(config.GetConfigPath())
			require.NoError(t, err)
			reply["content"] = string(content)
		case "detected-app":
			app := config.InstalledApp{ID: "browser-adoption-fixture", AppName: "Adoption fixture", InstallMethod: "fixture", InstallPath: root, Managed: false, AppType: "app"}
			require.NoError(t, config.AddInstalledApp(app))
			for _, saved := range config.GetInstalledApps() {
				if saved.AppName == app.AppName && saved.InstallPath == app.InstallPath {
					reply["appId"] = saved.ID
				}
			}
			require.NotEmpty(t, reply["appId"])
		case "create":
			jobType := cmd.JobType
			if jobType == "" {
				jobType = "install"
			}
			appID := cmd.AppID
			job, ok := server.jobManager.CreateJobWithResources(jobType, "fixture", "Browser fixture", resourceInstallerMutation)
			require.True(t, ok)
			result := make(chan string, 1)
			workers[job.ID] = result
			require.True(t, server.jobManager.StartWorker(job.ID, func() {
				select {
				case action := <-result:
					server.jobManager.AddOutput(job.ID, "worker terminal output")
					if action == "fail" {
						server.jobManager.SetError(job.ID, fmt.Errorf("fixture failed"), "Expected browser QA failure")
					} else {
						if jobType == "adopt" {
							require.NoError(t, config.UpdateInstalledAppManagedByID(appID, true, "none"))
						}
						server.jobManager.CompleteJob(job.ID)
					}
				case <-job.Context().Done():
					server.jobManager.AddOutput(job.ID, "cancellation cleanup complete")
					server.jobManager.SetError(job.ID, job.Context().Err(), "Fixture worker joined")
				}
			}))
			server.jobManager.UpdateProgress(job.ID, 25, "Staging fixture")
			reply["jobId"] = job.ID
		case "clients":
			server.jobManager.clientsMu.RLock()
			reply["clients"] = len(server.jobManager.clients)
			server.jobManager.clientsMu.RUnlock()
		case "modernz":
			opts := filepath.Join(config.GetMPVConfigPath(), "script-opts")
			require.NoError(t, os.MkdirAll(opts, 0700))
			require.NoError(t, os.WriteFile(filepath.Join(opts, "modernz.conf"), []byte("vidscale=auto\n"), 0600))
			require.NoError(t, config.Update(func(c *config.Config) error { c.UIConfigMigrations = nil; return nil }))
			scripts := filepath.Join(config.GetMPVConfigPath(), "scripts")
			require.NoError(t, os.MkdirAll(scripts, 0755))
			require.NoError(t, os.WriteFile(filepath.Join(scripts, "modernz.lua"), []byte("-- QA ModernZ presence fixture"), 0600))

		case "output":
			require.GreaterOrEqual(t, cmd.Lines, 0)
			require.LessOrEqual(t, cmd.Lines, 10000)
			for index := 0; index < cmd.Lines; index++ {
				server.jobManager.AddOutput(cmd.JobID, fmt.Sprintf("line %05d %s", index, strings.Repeat("x", 1024)))
			}
			server.jobManager.AddOutput(cmd.JobID, "LATEST OUTPUT SENTINEL")
		case "complete", "fail":
			result, ok := workers[cmd.JobID]
			require.True(t, ok)
			result <- cmd.Action
			delete(workers, cmd.JobID)
		case "cancel":
			require.NoError(t, server.jobManager.CancelJob(cmd.JobID))
		case "stop":
			respond(reply)
			return
		default:
			t.Fatalf("unknown fixture action %q", cmd.Action)
		}
		respond(reply)
	}
	require.NoError(t, scanner.Err())
}