// PicoClaw - Ultra-lightweight personal AI agent
// License: MIT
//
// Copyright (c) 2026 PicoClaw contributors

package ui

import (
	"fmt"
	"sync"

	"github.com/gdamore/tcell/v2"
	"github.com/rivo/tview"
	tuicfg "github.com/sipeed/picoclaw/cmd/picoclaw-launcher-tui/config"
)

// App is the root TUI application.
type App struct {
	tapp           *tview.Application
	pages          *tview.Pages
	pageStack      []string
	cfg            *tuicfg.TUIConfig
	configPath     string
	pageRefreshFns map[string]func()
	headerModelTV  *tview.TextView
	modalOpen      map[string]bool

	// OnModelSelected is called when a model is selected in the UI.
	// Can be nil to disable.
	OnModelSelected func(scheme tuicfg.Scheme, user tuicfg.User, modelID string)

	modelCache   map[string][]modelEntry
	modelCacheMu sync.RWMutex
	refreshMu    sync.Mutex
}

// cacheKey returns the map key for a (scheme, user) pair.
func cacheKey(schemeName, userName string) string {
	return fmt.Sprintf("%s/%s", schemeName, userName)
}

// cachedModels returns a defensive copy of the cached model list for a user (may be nil).
func (a *App) cachedModels(schemeName, userName string) []modelEntry {
	a.modelCacheMu.RLock()
	defer a.modelCacheMu.RUnlock()
	entries := a.modelCache[cacheKey(schemeName, userName)]
	return append([]modelEntry(nil), entries...)
}

// refreshModelCache fetches models for every user in the config concurrently.
// Serialized by refreshMu so concurrent calls don't race on the cache map.
// When all fetches complete it calls onDone via QueueUpdateDraw.
func (a *App) refreshModelCache(onDone func()) {
	go func() {
		a.refreshMu.Lock()
		defer a.refreshMu.Unlock()

		users := a.cfg.Provider.Users
		schemes := a.cfg.Provider.Schemes

		schemeURL := make(map[string]string, len(schemes))
		for _, s := range schemes {
			schemeURL[s.Name] = s.BaseURL
		}

		var wg sync.WaitGroup
		for _, u := range users {
			baseURL, ok := schemeURL[u.Scheme]
			if !ok || baseURL == "" {
				continue
			}
			if u.Key == "" {
				a.modelCacheMu.Lock()
				if a.modelCache == nil {
					a.modelCache = make(map[string][]modelEntry)
				}
				a.modelCache[cacheKey(u.Scheme, u.Name)] = nil
				a.modelCacheMu.Unlock()
				continue
			}
			wg.Add(1)
			u := u
			bURL := baseURL
			go func() {
				defer wg.Done()
				entries, err := fetchModels(bURL, u.Key)
				a.modelCacheMu.Lock()
				if a.modelCache == nil {
					a.modelCache = make(map[string][]modelEntry)
				}
				if err != nil || len(entries) == 0 {
					a.modelCache[cacheKey(u.Scheme, u.Name)] = nil
				} else {
					a.modelCache[cacheKey(u.Scheme, u.Name)] = entries
				}
				a.modelCacheMu.Unlock()
			}()
		}
		wg.Wait()

		if onDone != nil {
			a.tapp.QueueUpdateDraw(onDone)
		}
	}()
}

// New creates and wires up the TUI application.
func New(cfg *tuicfg.TUIConfig, configPath string) *App {
	// Cyberpunk Theme Colors
	// Dark background
	tview.Styles.PrimitiveBackgroundColor = tcell.NewHexColor(0x050510) // Deep Void
	tview.Styles.ContrastBackgroundColor = tcell.NewHexColor(0x1a1a2e)  // Dark Indigo
	tview.Styles.MoreContrastBackgroundColor = tcell.NewHexColor(0x2a2a40)

	// Borders and Titles
	tview.Styles.BorderColor = tcell.NewHexColor(0x00f0ff)   // Neon Cyan
	tview.Styles.TitleColor = tcell.NewHexColor(0x00f0ff)    // Neon Cyan
	tview.Styles.GraphicsColor = tcell.NewHexColor(0xff00ff) // Neon Magenta

	// Text
	tview.Styles.PrimaryTextColor = tcell.NewHexColor(0xe0e0e0)           // Off-white
	tview.Styles.SecondaryTextColor = tcell.NewHexColor(0x00f0ff)         // Neon Cyan
	tview.Styles.TertiaryTextColor = tcell.NewHexColor(0x39ff14)          // Neon Lime
	tview.Styles.InverseTextColor = tcell.NewHexColor(0x000000)           // Black
	tview.Styles.ContrastSecondaryTextColor = tcell.NewHexColor(0xff00ff) // Neon Magenta

	a := &App{
		tapp:           tview.NewApplication(),
		pages:          tview.NewPages(),
		pageStack:      []string{},
		cfg:            cfg,
		configPath:     configPath,
		pageRefreshFns: make(map[string]func()),
		modalOpen:      make(map[string]bool),
	}

	a.tapp.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
		if event.Key() == tcell.KeyEscape {
			if len(a.modalOpen) > 0 {
				return event
			}
			return a.goBack()
		}
		return event
	})

	a.buildPages()
	return a
}

// Run starts the TUI event loop.
func (a *App) Run() error {
	return a.tapp.SetRoot(a.pages, true).EnableMouse(true).Run()
}

func (a *App) buildPages() {
	a.pages.AddPage("home", a.newHomePage(), true, true)
	a.pageStack = []string{"home"}
}

func (a *App) navigateTo(name string, page tview.Primitive) {
	a.pages.RemovePage(name)
	a.pages.AddPage(name, page, true, false)
	a.pageStack = append(a.pageStack, name)
	a.pages.SwitchToPage(name)
}

func (a *App) goBack() *tcell.EventKey {
	if len(a.pageStack) <= 1 {
		return nil
	}
	popped := a.pageStack[len(a.pageStack)-1]
	a.pageStack = a.pageStack[:len(a.pageStack)-1]
	a.pages.RemovePage(popped)
	prev := a.pageStack[len(a.pageStack)-1]
	if fn, ok := a.pageRefreshFns[prev]; ok {
		fn()
	}
	if prev == "home" && a.headerModelTV != nil {
		a.headerModelTV.SetText(a.cfg.CurrentModelLabel() + "  ")
	}
	a.pages.SwitchToPage(prev)
	return nil
}

func (a *App) showModal(name string, primitive tview.Primitive) {
	a.modalOpen[name] = true
	a.pages.AddPage(name, primitive, true, true)
}

func (a *App) hideModal(name string) {
	delete(a.modalOpen, name)
	a.pages.HidePage(name)
	a.pages.RemovePage(name)
}

func (a *App) save() {
	if err := tuicfg.Save(a.configPath, a.cfg); err != nil {
		a.showError("save failed: " + err.Error())
	}
}

func (a *App) showError(msg string) {
	modal := tview.NewModal().
		SetText(" [red::b]ERROR[-::-]\n\n" + msg).
		AddButtons([]string{"OK"}).
		SetDoneFunc(func(_ int, _ string) {
			a.hideModal("error")
		})
	// Cyberpunk Modal Style
	modal.SetBackgroundColor(tcell.NewHexColor(0x1a1a2e))       // Deep Indigo
	modal.SetTextColor(tcell.NewHexColor(0xffffff))             // White
	modal.SetButtonBackgroundColor(tcell.NewHexColor(0xff2a2a)) // Neon Red
	modal.SetButtonTextColor(tcell.NewHexColor(0xffffff))       // White
	a.showModal("error", modal)
}

func (a *App) confirmDelete(label string, onConfirm func()) {
	modal := tview.NewModal().
		SetText(" [red::b]DELETE WARNING[-::-]\n\nDelete " + label + "?\n[gray]This action cannot be undone.[-]").
		AddButtons([]string{"Delete", "Cancel"}).
		SetDoneFunc(func(_ int, buttonLabel string) {
			a.hideModal("confirm-delete")
			if buttonLabel == "Delete" {
				onConfirm()
			}
		})
	// Cyberpunk Modal Style
	modal.SetBackgroundColor(tcell.NewHexColor(0x1a1a2e))       // Deep Indigo
	modal.SetTextColor(tcell.NewHexColor(0xffffff))             // White
	modal.SetButtonBackgroundColor(tcell.NewHexColor(0xff2a2a)) // Neon Red for danger
	modal.SetButtonTextColor(tcell.NewHexColor(0xffffff))       // White
	a.showModal("confirm-delete", modal)
}

func centeredForm(form *tview.Form, widthPct, height int) tview.Primitive {
	return tview.NewFlex().
		AddItem(tview.NewBox(), 0, 1, false).
		AddItem(tview.NewFlex().SetDirection(tview.FlexRow).
			AddItem(tview.NewBox(), 0, 1, false).
			AddItem(form, height, 1, true).
			AddItem(tview.NewBox(), 0, 1, false), 0, widthPct, true).
		AddItem(tview.NewBox(), 0, 1, false)
}

func hintBar(text string) *tview.TextView {
	tv := tview.NewTextView().
		SetText(text).
		SetDynamicColors(true).
		SetTextAlign(tview.AlignCenter).
		SetTextColor(tcell.NewHexColor(0x00f0ff)) // Neon Cyan
	tv.SetBackgroundColor(tcell.NewHexColor(0x2a2a40)) // Darker Indigo
	return tv
}

func (a *App) buildShell(pageID string, content tview.Primitive, hint string) tview.Primitive {
	var modelTV *tview.TextView
	if pageID == "home" {
		if a.headerModelTV == nil {
			a.headerModelTV = tview.NewTextView()
			a.headerModelTV.SetTextAlign(tview.AlignRight).
				SetTextColor(tcell.NewHexColor(0x39ff14)). // Neon Lime
				SetDynamicColors(true).
				SetBackgroundColor(tcell.NewHexColor(0x050510))
		}
		modelTV = a.headerModelTV
		modelTV.SetText("MODEL: " + a.cfg.CurrentModelLabel() + " ")
	} else {
		modelTV = tview.NewTextView()
		modelTV.SetBackgroundColor(tcell.NewHexColor(0x050510))
	}

	headerLeft := tview.NewTextView().
		SetText(" [#ff00ff::b]///[#00f0ff] PICOCLAW LAUNCHER [#ff00ff]///").
		SetDynamicColors(true).
		SetBackgroundColor(tcell.NewHexColor(0x050510))

	header := tview.NewFlex().
		AddItem(headerLeft, 0, 1, false).
		AddItem(modelTV, 0, 1, false)

	sidebar := tview.NewTextView().
		SetDynamicColors(true).
		SetWrap(false)
	sidebar.SetBackgroundColor(tcell.NewHexColor(0x1a1a2e)) // Deep Indigo

	// Cyberpunk Sidebar Styling
	activePrefix := "[#39ff14::b]>> " // Neon Lime arrow
	activeSuffix := "[-]"
	inactivePrefix := "[#808080]   "
	inactiveSuffix := "[-]"

	sbText := "\n\n" // Top padding

	menuItem := func(id, label string) string {
		if pageID == id {
			return activePrefix + label + activeSuffix + "\n\n"
		}
		return inactivePrefix + label + inactiveSuffix + "\n\n"
	}

	sbText += menuItem("home", "HOME")
	sbText += menuItem("schemes", "SCHEMES")
	sbText += menuItem("users", "USERS")
	sbText += menuItem("models", "MODELS")

	sidebar.SetText(sbText)

	footer := hintBar(hint)

	grid := tview.NewGrid().
		SetRows(1, 0, 1).
		SetColumns(20, 0). // Slightly wider sidebar
		AddItem(header, 0, 0, 1, 2, 0, 0, false).
		AddItem(sidebar, 1, 0, 1, 1, 0, 0, false).
		AddItem(content, 1, 1, 1, 1, 0, 0, true).
		AddItem(footer, 2, 0, 1, 2, 0, 0, false)

	// Add a border around the content area if possible, or ensure content has its own border
	// grid.SetBorders(false) // Grid borders usually look bad, handled by components

	return grid
}