package main

import (
	"fmt"
	"io"

	"github.com/charmbracelet/bubbles/key"
	"github.com/charmbracelet/bubbles/list"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"
)

// WrappingDelegate is a delegate that wraps text instead of truncating it.
// It's based on the DefaultDelegate but modified to use text wrapping.
type WrappingDelegate struct {
	ShowDescription bool
	Styles          list.DefaultItemStyles
	UpdateFunc      func(tea.Msg, *list.Model) tea.Cmd
	ShortHelpFunc   func() []key.Binding
	FullHelpFunc    func() [][]key.Binding
	height          int
	spacing         int
}

// NewWrappingDelegate creates a new delegate with wrapping behavior and default styles.
func NewWrappingDelegate() WrappingDelegate {
	const defaultHeight = 2
	const defaultSpacing = 1
	return WrappingDelegate{
		ShowDescription: true,
		Styles:          list.NewDefaultItemStyles(),
		height:          defaultHeight,
		spacing:         defaultSpacing,
	}
}

// SetHeight sets delegate's preferred height.
func (d *WrappingDelegate) SetHeight(i int) {
	d.height = i
}

// Height returns the delegate's preferred height.
// This has effect only if ShowDescription is true,
// otherwise height is always 1.
func (d WrappingDelegate) Height() int {
	if d.ShowDescription {
		return d.height
	}
	return 1
}

// SetSpacing sets the delegate's spacing.
func (d *WrappingDelegate) SetSpacing(i int) {
	d.spacing = i
}

// Spacing returns the delegate's spacing.
func (d WrappingDelegate) Spacing() int {
	return d.spacing
}

// Update checks whether the delegate's UpdateFunc is set and calls it.
func (d WrappingDelegate) Update(msg tea.Msg, m *list.Model) tea.Cmd {
	if d.UpdateFunc == nil {
		return nil
	}
	return d.UpdateFunc(msg, m)
}

// wrapText wraps text to the specified width using lipgloss
func wrapText(text string, width int, style lipgloss.Style) string {
	if width <= 0 {
		return text
	}
	return style.Width(width).Render(text)
}

// Render prints an item with text wrapping instead of truncation.
func (d WrappingDelegate) Render(w io.Writer, m list.Model, index int, item list.Item) {
	var (
		title, desc  string
		matchedRunes []int
		s            = &d.Styles
	)

	if i, ok := item.(list.DefaultItem); ok {
		title = i.Title()
		desc = i.Description()
	} else {
		return
	}

	if m.Width() <= 0 {
		// short-circuit
		return
	}

	// Calculate available text width
	textwidth := m.Width() - s.NormalTitle.GetPaddingLeft() - s.NormalTitle.GetPaddingRight()

	// Conditions
	var (
		isSelected  = index == m.Index()
		emptyFilter = m.FilterState() == list.Filtering && m.FilterValue() == ""
		isFiltered  = m.FilterState() == list.Filtering || m.FilterState() == list.FilterApplied
	)

	if isFiltered && index < len(m.VisibleItems()) {
		// Get indices of matched characters
		matchedRunes = m.MatchesForItem(index)
	}

	// Apply styling and wrapping based on state
	if emptyFilter {
		title = wrapText(title, textwidth, s.DimmedTitle)
		if d.ShowDescription {
			desc = wrapText(desc, textwidth, s.DimmedDesc)
		}
	} else if isSelected && m.FilterState() != list.Filtering {
		if isFiltered {
			// Highlight matches
			unmatched := s.SelectedTitle.Inline(true)
			matched := unmatched.Inherit(s.FilterMatch)
			title = lipgloss.StyleRunes(title, matchedRunes, matched, unmatched)
		}
		title = wrapText(title, textwidth, s.SelectedTitle)
		if d.ShowDescription {
			desc = wrapText(desc, textwidth, s.SelectedDesc)
		}
	} else {
		if isFiltered {
			// Highlight matches
			unmatched := s.NormalTitle.Inline(true)
			matched := unmatched.Inherit(s.FilterMatch)
			title = lipgloss.StyleRunes(title, matchedRunes, matched, unmatched)
		}
		title = wrapText(title, textwidth, s.NormalTitle)
		if d.ShowDescription {
			desc = wrapText(desc, textwidth, s.NormalDesc)
		}
	}

	if d.ShowDescription {
		fmt.Fprintf(w, "%s\n%s", title, desc) //nolint: errcheck
		return
	}
	fmt.Fprintf(w, "%s", title) //nolint: errcheck
}

// ShortHelp returns the delegate's short help.
func (d WrappingDelegate) ShortHelp() []key.Binding {
	if d.ShortHelpFunc != nil {
		return d.ShortHelpFunc()
	}
	return nil
}

// FullHelp returns the delegate's full help.
func (d WrappingDelegate) FullHelp() [][]key.Binding {
	if d.FullHelpFunc != nil {
		return d.FullHelpFunc()
	}
	return nil
}