package chat

import (
	"fmt"
	"log/slog"
	"strings"

	"github.com/charmbracelet/bubbles/v2/spinner"
	tea "github.com/charmbracelet/bubbletea/v2"
	"github.com/charmbracelet/lipgloss/v2"
	"github.com/sst/opencode/internal/app"
	"github.com/sst/opencode/internal/commands"
	"github.com/sst/opencode/internal/components/dialog"
	"github.com/sst/opencode/internal/components/textarea"
	"github.com/sst/opencode/internal/image"
	"github.com/sst/opencode/internal/styles"
	"github.com/sst/opencode/internal/theme"
	"github.com/sst/opencode/internal/util"
)

type EditorComponent interface {
	tea.Model
	View(width int) string
	Content(width int) string
	Lines() int
	Value() string
	Focused() bool
	Focus() (tea.Model, tea.Cmd)
	Blur()
	Submit() (tea.Model, tea.Cmd)
	Clear() (tea.Model, tea.Cmd)
	Paste() (tea.Model, tea.Cmd)
	Newline() (tea.Model, tea.Cmd)
	SetInterruptKeyInDebounce(inDebounce bool)
}

type editorComponent struct {
	app                    *app.App
	textarea               textarea.Model
	attachments            []app.Attachment
	spinner                spinner.Model
	interruptKeyInDebounce bool
}

func (m *editorComponent) Init() tea.Cmd {
	return tea.Batch(m.textarea.Focus(), m.spinner.Tick, tea.EnableReportFocus)
}

func (m *editorComponent) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd
	var cmd tea.Cmd

	switch msg := msg.(type) {
	case spinner.TickMsg:
		m.spinner, cmd = m.spinner.Update(msg)
		return m, cmd
	case tea.KeyPressMsg:
		// Maximize editor responsiveness for printable characters
		if msg.Text != "" {
			m.textarea, cmd = m.textarea.Update(msg)
			cmds = append(cmds, cmd)
			return m, tea.Batch(cmds...)
		}
	case dialog.ThemeSelectedMsg:
		m.textarea = createTextArea(&m.textarea)
		m.spinner = createSpinner()
		return m, tea.Batch(m.spinner.Tick, m.textarea.Focus())
	case dialog.CompletionSelectedMsg:
		if msg.IsCommand {
			commandName := strings.TrimPrefix(msg.CompletionValue, "/")
			updated, cmd := m.Clear()
			m = updated.(*editorComponent)
			cmds = append(cmds, cmd)
			cmds = append(cmds, util.CmdHandler(commands.ExecuteCommandMsg(m.app.Commands[commands.CommandName(commandName)])))
			return m, tea.Batch(cmds...)
		} else {
			existingValue := m.textarea.Value()

			// Replace the current token (after last space)
			lastSpaceIndex := strings.LastIndex(existingValue, " ")
			if lastSpaceIndex == -1 {
				m.textarea.SetValue(msg.CompletionValue + " ")
			} else {
				modifiedValue := existingValue[:lastSpaceIndex+1] + msg.CompletionValue
				m.textarea.SetValue(modifiedValue + " ")
			}
			return m, nil
		}
	}

	m.spinner, cmd = m.spinner.Update(msg)
	cmds = append(cmds, cmd)

	m.textarea, cmd = m.textarea.Update(msg)
	cmds = append(cmds, cmd)

	return m, tea.Batch(cmds...)
}

func (m *editorComponent) Content(width int) string {
	t := theme.CurrentTheme()
	base := styles.NewStyle().Foreground(t.Text()).Background(t.Background()).Render
	muted := styles.NewStyle().Foreground(t.TextMuted()).Background(t.Background()).Render
	promptStyle := styles.NewStyle().Foreground(t.Primary()).
		Padding(0, 0, 0, 1).
		Bold(true)
	prompt := promptStyle.Render(">")

	m.textarea.SetWidth(width - 6)
	textarea := lipgloss.JoinHorizontal(
		lipgloss.Top,
		prompt,
		m.textarea.View(),
	)
	textarea = styles.NewStyle().
		Background(t.BackgroundElement()).
		Width(width).
		PaddingTop(1).
		PaddingBottom(1).
		BorderStyle(lipgloss.ThickBorder()).
		BorderForeground(t.Border()).
		BorderBackground(t.Background()).
		BorderLeft(true).
		BorderRight(true).
		Render(textarea)

	hint := base(m.getSubmitKeyText()) + muted(" send   ")
	if m.app.IsBusy() {
		keyText := m.getInterruptKeyText()
		if m.interruptKeyInDebounce {
			hint = muted("working") + m.spinner.View() + muted("  ") + base(keyText+" again") + muted(" interrupt")
		} else {
			hint = muted("working") + m.spinner.View() + muted("  ") + base(keyText) + muted(" interrupt")
		}
	}

	model := ""
	if m.app.Model != nil {
		model = muted(m.app.Provider.Name) + base(" "+m.app.Model.Name)
	}

	space := width - 2 - lipgloss.Width(model) - lipgloss.Width(hint)
	spacer := styles.NewStyle().Background(t.Background()).Width(space).Render("")

	info := hint + spacer + model
	info = styles.NewStyle().Background(t.Background()).Padding(0, 1).Render(info)

	content := strings.Join([]string{"", textarea, info}, "\n")
	return content
}

func (m *editorComponent) View(width int) string {
	if m.Lines() > 1 {
		return lipgloss.Place(
			width,
			5,
			lipgloss.Center,
			lipgloss.Center,
			"",
			styles.WhitespaceStyle(theme.CurrentTheme().Background()),
		)
	}
	return m.Content(width)
}

func (m *editorComponent) Focused() bool {
	return m.textarea.Focused()
}

func (m *editorComponent) Focus() (tea.Model, tea.Cmd) {
	return m, m.textarea.Focus()
}

func (m *editorComponent) Blur() {
	m.textarea.Blur()
}

func (m *editorComponent) Lines() int {
	return m.textarea.LineCount()
}

func (m *editorComponent) Value() string {
	return m.textarea.Value()
}

func (m *editorComponent) Submit() (tea.Model, tea.Cmd) {
	value := strings.TrimSpace(m.Value())
	if value == "" {
		return m, nil
	}
	if len(value) > 0 && value[len(value)-1] == '\\' {
		// If the last character is a backslash, remove it and add a newline
		m.textarea.SetValue(value[:len(value)-1] + "\n")
		return m, nil
	}

	var cmds []tea.Cmd
	updated, cmd := m.Clear()
	m = updated.(*editorComponent)
	cmds = append(cmds, cmd)

	attachments := m.attachments
	m.attachments = nil

	cmds = append(cmds, util.CmdHandler(app.SendMsg{Text: value, Attachments: attachments}))
	return m, tea.Batch(cmds...)
}

func (m *editorComponent) Clear() (tea.Model, tea.Cmd) {
	m.textarea.Reset()
	return m, nil
}

func (m *editorComponent) Paste() (tea.Model, tea.Cmd) {
	imageBytes, text, err := image.GetImageFromClipboard()
	if err != nil {
		slog.Error(err.Error())
		return m, nil
	}
	if len(imageBytes) != 0 {
		attachmentName := fmt.Sprintf("clipboard-image-%d", len(m.attachments))
		attachment := app.Attachment{FilePath: attachmentName, FileName: attachmentName, Content: imageBytes, MimeType: "image/png"}
		m.attachments = append(m.attachments, attachment)
	} else {
		m.textarea.SetValue(m.textarea.Value() + text)
	}
	return m, nil
}

func (m *editorComponent) Newline() (tea.Model, tea.Cmd) {
	m.textarea.Newline()
	return m, nil
}

func (m *editorComponent) SetInterruptKeyInDebounce(inDebounce bool) {
	m.interruptKeyInDebounce = inDebounce
}

func (m *editorComponent) getInterruptKeyText() string {
	return m.app.Commands[commands.SessionInterruptCommand].Keys()[0]
}

func (m *editorComponent) getSubmitKeyText() string {
	return m.app.Commands[commands.InputSubmitCommand].Keys()[0]
}

func createTextArea(existing *textarea.Model) textarea.Model {
	t := theme.CurrentTheme()
	bgColor := t.BackgroundElement()
	textColor := t.Text()
	textMutedColor := t.TextMuted()

	ta := textarea.New()

	ta.Styles.Blurred.Base = styles.NewStyle().Foreground(textColor).Background(bgColor).Lipgloss()
	ta.Styles.Blurred.CursorLine = styles.NewStyle().Background(bgColor).Lipgloss()
	ta.Styles.Blurred.Placeholder = styles.NewStyle().Foreground(textMutedColor).Background(bgColor).Lipgloss()
	ta.Styles.Blurred.Text = styles.NewStyle().Foreground(textColor).Background(bgColor).Lipgloss()
	ta.Styles.Focused.Base = styles.NewStyle().Foreground(textColor).Background(bgColor).Lipgloss()
	ta.Styles.Focused.CursorLine = styles.NewStyle().Background(bgColor).Lipgloss()
	ta.Styles.Focused.Placeholder = styles.NewStyle().Foreground(textMutedColor).Background(bgColor).Lipgloss()
	ta.Styles.Focused.Text = styles.NewStyle().Foreground(textColor).Background(bgColor).Lipgloss()
	ta.Styles.Cursor.Color = t.Primary()

	ta.Prompt = " "
	ta.ShowLineNumbers = false
	ta.CharLimit = -1

	if existing != nil {
		ta.SetValue(existing.Value())
		// ta.SetWidth(existing.Width())
		ta.SetHeight(existing.Height())
	}

	return ta
}

func createSpinner() spinner.Model {
	t := theme.CurrentTheme()
	return spinner.New(
		spinner.WithSpinner(spinner.Ellipsis),
		spinner.WithStyle(
			styles.NewStyle().
				Background(t.Background()).
				Foreground(t.TextMuted()).
				Width(3).
				Lipgloss(),
		),
	)
}

func NewEditorComponent(app *app.App) EditorComponent {
	s := createSpinner()
	ta := createTextArea(nil)

	return &editorComponent{
		app:                    app,
		textarea:               ta,
		spinner:                s,
		interruptKeyInDebounce: false,
	}
}