package completions

import (
	"github.com/charmbracelet/bubbles/v2/key"
	tea "github.com/charmbracelet/bubbletea/v2"
	"github.com/charmbracelet/crush/internal/tui/components/core/list"
	"github.com/charmbracelet/crush/internal/tui/styles"
	"github.com/charmbracelet/crush/internal/tui/util"
	"github.com/charmbracelet/lipgloss/v2"
)

type Completion struct {
	Title string // The title of the completion item
	Value any    // The value of the completion item
}

type OpenCompletionsMsg struct {
	Completions []Completion
	X           int // X position for the completions popup
	Y           int // Y position for the completions popup
}

type FilterCompletionsMsg struct {
	Query string // The query to filter completions
}

type CompletionsClosedMsg struct{}

type CloseCompletionsMsg struct{}

type SelectCompletionMsg struct {
	Value any // The value of the selected completion item
}

type Completions interface {
	util.Model
	Open() bool
	Query() string // Returns the current filter query
	KeyMap() KeyMap
	Position() (int, int) // Returns the X and Y position of the completions popup
}

type completionsCmp struct {
	width  int
	height int  // Height of the completions component`
	x      int  // X position for the completions popup\
	y      int  // Y position for the completions popup
	open   bool // Indicates if the completions are open
	keyMap KeyMap

	list  list.ListModel
	query string // The current filter query
}

func New() Completions {
	completionsKeyMap := DefaultKeyMap()
	keyMap := list.DefaultKeyMap()
	keyMap.Up.SetEnabled(false)
	keyMap.Down.SetEnabled(false)
	keyMap.HalfPageDown.SetEnabled(false)
	keyMap.HalfPageUp.SetEnabled(false)
	keyMap.Home.SetEnabled(false)
	keyMap.End.SetEnabled(false)
	keyMap.UpOneItem = completionsKeyMap.Up
	keyMap.DownOneItem = completionsKeyMap.Down

	l := list.New(
		list.WithReverse(true),
		list.WithKeyMap(keyMap),
		list.WithHideFilterInput(true),
	)
	return &completionsCmp{
		width:  30,
		height: 10,
		list:   l,
		query:  "",
		keyMap: completionsKeyMap,
	}
}

// Init implements Completions.
func (c *completionsCmp) Init() tea.Cmd {
	return tea.Sequence(
		c.list.Init(),
		c.list.SetSize(c.width, c.height),
	)
}

// Update implements Completions.
func (c *completionsCmp) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyPressMsg:
		switch {
		case key.Matches(msg, c.keyMap.Up):
			u, cmd := c.list.Update(msg)
			c.list = u.(list.ListModel)
			return c, cmd

		case key.Matches(msg, c.keyMap.Down):
			d, cmd := c.list.Update(msg)
			c.list = d.(list.ListModel)
			return c, cmd
		case key.Matches(msg, c.keyMap.Select):
			selectedItemInx := c.list.SelectedIndex()
			if selectedItemInx == list.NoSelection {
				return c, nil // No item selected, do nothing
			}
			items := c.list.Items()
			selectedItem := items[selectedItemInx].(CompletionItem).Value()
			c.open = false // Close completions after selection
			return c, util.CmdHandler(SelectCompletionMsg{
				Value: selectedItem,
			})
		case key.Matches(msg, c.keyMap.Cancel):
			if c.open {
				c.open = false
				return c, util.CmdHandler(CompletionsClosedMsg{})
			}
		}
	case CloseCompletionsMsg:
		c.open = false
		c.query = ""
		return c, tea.Batch(
			c.list.SetItems([]util.Model{}),
			util.CmdHandler(CompletionsClosedMsg{}),
		)
	case OpenCompletionsMsg:
		c.open = true
		c.query = ""
		c.x = msg.X
		c.y = msg.Y
		items := []util.Model{}
		t := styles.CurrentTheme()
		for _, completion := range msg.Completions {
			item := NewCompletionItem(completion.Title, completion.Value, WithBackgroundColor(t.BgSubtle))
			items = append(items, item)
		}
		c.height = max(min(10, len(items)), 1) // Ensure at least 1 item height
		cmds := []tea.Cmd{
			c.list.SetSize(c.width, c.height),
			c.list.SetItems(items),
		}
		return c, tea.Batch(cmds...)
	case FilterCompletionsMsg:
		c.query = msg.Query
		if !c.open {
			return c, nil // If completions are not open, do nothing
		}
		cmd := c.list.Filter(msg.Query)
		c.height = max(min(10, len(c.list.Items())), 1)
		return c, tea.Batch(
			cmd,
			c.list.SetSize(c.width, c.height),
		)
	}
	return c, nil
}

// View implements Completions.
func (c *completionsCmp) View() tea.View {
	if len(c.list.Items()) == 0 {
		return tea.NewView(c.style().Render("No completions found"))
	}

	view := tea.NewView(
		c.style().Render(c.list.View().String()),
	)
	return view
}

func (c *completionsCmp) style() lipgloss.Style {
	t := styles.CurrentTheme()
	return t.S().Base.
		Width(c.width).
		Height(c.height).
		Background(t.BgSubtle)
}

func (c *completionsCmp) Open() bool {
	return c.open
}

func (c *completionsCmp) Query() string {
	return c.query
}

func (c *completionsCmp) KeyMap() KeyMap {
	return c.keyMap
}

func (c *completionsCmp) Position() (int, int) {
	return c.x, c.y - c.height
}