package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	tea "github.com/charmbracelet/bubbletea"
)

func main() {
	if handled, err := handleCompletionCommand(os.Args[1:], os.Stdout); handled {
		if err != nil {
			exitf("%v", err)
		}
		return
	}
	defaults := defaultConfig()
	defaultConfigPath, err := configPath()
	if err != nil {
		exitf("configuration: %v", err)
	}
	flag.Usage = func() {
		writeCLIHelp(flag.CommandLine.Output(), defaults, defaultConfigPath)
	}
	if len(os.Args) == 2 && os.Args[1] == "help" {
		flag.Usage()
		return
	}
	var (
		configFile     = flag.String("config", defaultConfigPath, "TOML configuration file")
		repo           = flag.String("repo", "", "limit pull requests to an owner/repository")
		poll           = flag.Duration("poll", defaults.RefreshInterval.Duration, "base interval between GitHub refreshes")
		showAll        = flag.Bool("all", defaults.ShowAll, "show every open PR in --repo instead of only assigned PRs")
		limit          = flag.Int("limit", defaults.Limit, "maximum number of open pull requests to load")
		endpoint       = flag.String("endpoint", defaults.Endpoint, "GitHub GraphQL API endpoint")
		theme          = flag.String("theme", defaults.Theme, "built-in or custom color theme")
		foldResolved   = flag.Bool("fold-resolved", defaults.Display.FoldResolved, "start resolved review threads folded")
		listWidth      = flag.Int("thread-list-width", defaults.Display.ThreadListWidthPercent, "thread-list width as a percentage of the terminal")
		dashboardMode  = flag.String("dashboard-mode", defaults.Display.DashboardMode, "open the dashboard by hotkey or as an intermediate screen")
		compactReviews = flag.Bool("compact-reviews", defaults.Display.CompactReviews, "aggregate repeated submitted-review entries")
		pathScroll     = flag.Bool("path-scroll", defaults.Paths.Scroll, "scroll file paths that do not fit")
		pathScrollRate = flag.Duration("path-scroll-interval", defaults.Paths.ScrollInterval.Duration, "interval between file-path scroll steps")
		cacheEnabled   = flag.Bool("cache", defaults.Cache.Enabled, "enable the local read cache and offline fallback")
		cacheMaxAge    = flag.Duration("cache-max-age", defaults.Cache.MaxAge.Duration, "oldest cache entry accepted for offline fallback")
		cacheDir       = flag.String("cache-dir", defaults.Cache.Directory, "local read-cache directory")
		editorMode     = flag.String("editor-mode", defaults.Editing.Mode, "description editor mode")
	)
	flag.Parse()
	if flag.NArg() != 0 {
		exitf("unexpected argument %q; run 'diple --help' for usage", flag.Arg(0))
	}

	visited := map[string]bool{}
	flag.Visit(func(item *flag.Flag) { visited[item.Name] = true })
	config, err := loadConfig(
		*configFile,
		visited["config"] || os.Getenv("DIPLE_CONFIG") != "" ||
			os.Getenv("GH_THREADS_CONFIG") != "",
	)
	if err != nil {
		exitf("configuration: %v", err)
	}
	if visited["repo"] {
		config.Repository = *repo
	} else if envRepo := os.Getenv("GH_REPO"); envRepo != "" {
		config.Repository = envRepo
	}
	if visited["poll"] {
		config.RefreshInterval.Duration = *poll
	}
	if visited["all"] {
		config.ShowAll = *showAll
	}
	if visited["limit"] {
		config.Limit = *limit
	}
	if visited["endpoint"] {
		config.Endpoint = *endpoint
	}
	if visited["theme"] {
		config.Theme = *theme
	}
	if visited["fold-resolved"] {
		config.Display.FoldResolved = *foldResolved
	}
	if visited["thread-list-width"] {
		config.Display.ThreadListWidthPercent = *listWidth
	}
	if visited["dashboard-mode"] {
		config.Display.DashboardMode = *dashboardMode
	}
	if visited["compact-reviews"] {
		config.Display.CompactReviews = *compactReviews
	}
	if visited["path-scroll"] {
		config.Paths.Scroll = *pathScroll
	}
	if visited["path-scroll-interval"] {
		config.Paths.ScrollInterval.Duration = *pathScrollRate
	}
	if visited["cache"] {
		config.Cache.Enabled = *cacheEnabled
	}
	if visited["cache-max-age"] {
		config.Cache.MaxAge.Duration = *cacheMaxAge
	}
	if visited["cache-dir"] {
		config.Cache.Directory = *cacheDir
	}
	if visited["editor-mode"] {
		config.Editing.Mode = *editorMode
	}
	if err := validateConfig(config); err != nil {
		exitf("configuration: %v", err)
	}

	var owner, name string
	if config.Repository != "" {
		parts := strings.Split(config.Repository, "/")
		if len(parts) != 2 || parts[0] == "" || parts[1] == "" {
			exitf("--repo must be owner/name")
		}
		owner, name = parts[0], parts[1]
	}
	if err := applyTheme(config.Theme, config.CustomTheme); err != nil {
		exitf("configuration: %v", err)
	}
	token, err := resolveToken(config.Endpoint)
	if err != nil {
		exitf("authenticate: %v", err)
	}

	client := NewGitHubClient(config.Endpoint, token)
	var service GitHubService = client
	if config.Cache.Enabled {
		cacheDir := config.Cache.Directory
		if cacheDir == "" {
			cacheDir, err = defaultCacheDir()
			if err != nil {
				exitf("configuration: %v", err)
			}
		}
		service = NewCachedGitHubService(
			client, cacheDir, config.Cache.MaxAge.Duration, config.Cache.MaxEntries,
		)
	}
	statePath := filepath.Join(filepath.Dir(*configFile), "state.json")
	draftPath := filepath.Join(filepath.Dir(*configFile), "drafts.json")
	var aiController *AIController
	var aiStore *AIStore
	if config.AI.Enabled {
		aiDir := config.AI.StoreDirectory
		if aiDir == "" {
			aiDir = filepath.Join(filepath.Dir(*configFile), "ai")
		}
		aiStore = NewAIStore(aiDir)
		diffService, ok := service.(AIDiffService)
		if !ok {
			exitf("configuration: GitHub service cannot provide authenticated PR diffs")
		}
		workingDirectory, cwdErr := os.Getwd()
		if cwdErr != nil {
			exitf("configuration: determine working directory: %v", cwdErr)
		}
		aiController = &AIController{
			config:   config.AI,
			provider: NewCodexCLIProvider(config.AI, workingDirectory),
			diffs:    diffService,
			store:    aiStore,
		}
	}
	app := NewAppWithSettings(
		service, owner, name, config.ShowAll, config.Limit, config.RefreshInterval.Duration,
		AppSettings{
			FoldResolved:           config.Display.FoldResolved,
			ThreadListWidthPercent: config.Display.ThreadListWidthPercent,
			DashboardMode:          config.Display.DashboardMode,
			CompactReviews:         config.Display.CompactReviews,
			ViewerLabel:            config.Display.ViewerLabel,
			ReadState:              loadReadState(statePath),
			Drafts:                 loadDraftStore(draftPath),
			PathScroll:             config.Paths.Scroll,
			PathScrollInterval:     config.Paths.ScrollInterval.Duration,
			ThreadStatusOrder:      config.Threads.StatusOrder,
			ThreadWithinStatus:     config.Threads.WithinStatus,
			EditorMode:             config.Editing.Mode,
			KeyBindings:            config.KeyBindings,
			AI:                     aiController,
			AIStore:                aiStore,
		},
	)
	cursorOutput := newTerminalCursorOutput(os.Stdout)
	app.cursorOutput = cursorOutput
	if _, err := tea.NewProgram(
		app,
		tea.WithAltScreen(),
		tea.WithOutput(cursorOutput),
	).Run(); err != nil {
		exitf("run TUI: %v", err)
	}
}

func firstNonEmpty(values ...string) string {
	for _, value := range values {
		if value != "" {
			return value
		}
	}
	return ""
}

func exitf(format string, args ...any) {
	fmt.Fprintf(os.Stderr, "diple: "+format+"\n", args...)
	os.Exit(1)
}

// Keep interface drift visible at compile time.
var _ GitHubService = (*GitHubClient)(nil)
var _ GitHubMergeService = (*GitHubClient)(nil)
var _ GitHubMergeService = (*CachedGitHubService)(nil)
var _ GitHubWriteService = (*GitHubClient)(nil)
var _ GitHubWriteService = (*CachedGitHubService)(nil)
var _ GitHubPullRequestWriteService = (*GitHubClient)(nil)
var _ GitHubPullRequestWriteService = (*CachedGitHubService)(nil)