package ui

import (
	"fmt"

	"codeflow.dananglin.me.uk/apollo/pelican/internal/board"
	"github.com/gdamore/tcell/v2"
	"github.com/rivo/tview"
)

type card struct {
	id           int
	wrappedTitle []string
	created      string
	height       int
}

type column struct {
	*tview.Box

	statusID         int
	statusName       string
	cards            []card
	focusedCard      int
	getBoardModeFunc func() boardMode
}

func newColumn(statusID int, statusName string, getBoardModeFunc func() boardMode) *column {
	column := column{
		Box:              tview.NewBox(),
		statusID:         statusID,
		statusName:       statusName,
		cards:            nil,
		focusedCard:      0,
		getBoardModeFunc: getBoardModeFunc,
	}

	column.SetBorder(true)

	return &column
}

func (c *column) addCard(cardID int, title, created string) {
	wrappedTitle := tview.WordWrap(title, 40)
	metadataHeight := 1
	height := len(wrappedTitle) + metadataHeight

	card := card{
		id:           cardID,
		wrappedTitle: wrappedTitle,
		created:      created,
		height:       height,
	}

	c.cards = append(c.cards, card)
}

func (c *column) shiftCardFocus(movement boardMovement) {
	numCards := len(c.cards)

	switch movement {
	case next:
		if c.focusedCard == numCards-1 {
			c.focusedCard = 0
		} else {
			c.focusedCard++
		}
	case previous:
		if c.focusedCard == 0 {
			c.focusedCard = numCards - 1
		} else {
			c.focusedCard--
		}
	}
}

func (c *column) clear() {
	c.cards = nil
	c.focusedCard = 0
}

func (c *column) update(kanban board.Board) error {
	c.clear()

	status, err := kanban.Status(c.statusID)
	if err != nil {
		return fmt.Errorf("unable to retrieve details about Status %d from the database; %w", c.statusID, err)
	}

	numCardIDs := len(status.CardIds)

	if status.CardIds != nil && numCardIDs > 0 {
		cards, err := kanban.CardList(status.CardIds)
		if err != nil {
			return fmt.Errorf("unable to get the list of cards from Status %d; %w", c.statusID, err)
		}

		for _, card := range cards {
			c.addCard(card.ID, card.Title, card.Created)
		}
	}

	c.statusName = status.Name

	c.SetTitle(fmt.Sprintf(" %s (%d) ", c.statusName, numCardIDs))

	return nil
}

// InputHandler returns the handler for this primitive.
func (c *column) InputHandler() func(event *tcell.EventKey, setFocus func(p tview.Primitive)) {
	return c.WrapInputHandler(func(event *tcell.EventKey, _ func(p tview.Primitive)) {
		key, letter := event.Key(), event.Rune()
		switch {
		case key == tcell.KeyDown || letter == 'j':
			c.shiftCardFocus(next)
		case key == tcell.KeyUp || letter == 'k':
			c.shiftCardFocus(previous)
		}
	})
}

func (c *column) Draw(screen tcell.Screen) {
	var mode boardMode

	// Update border before calling c.DrawForSubclass()
	if c.getBoardModeFunc == nil {
		mode = normal
	} else {
		mode = c.getBoardModeFunc()
	}

	if mode == selection {
		if c.HasFocus() {
			c.SetBorderColor(tcell.ColorTurquoise.TrueColor())
		} else {
			c.SetBorderColor(tcell.ColorOrangeRed.TrueColor())
		}
	} else {
		c.SetBorderColor(tcell.ColorOrangeRed.TrueColor())
	}

	c.DrawForSubclass(screen, c)

	x, y, width, _ := c.GetInnerRect()

	xOffset := x + 1
	cursor := y
	gap := 1

	for ind := 0; ind < len(c.cards); ind++ {
		var (
			style    tcell.Style
			vertLine rune
		)

		if c.HasFocus() && ind == c.focusedCard && mode == normal {
			vertLine = tview.BoxDrawingsHeavyVertical
			style = tcell.StyleDefault.Foreground(tcell.ColorBlue.TrueColor())
		} else {
			vertLine = tview.BoxDrawingsLightVertical
			style = tcell.StyleDefault.Foreground(tcell.ColorYellow.TrueColor())
		}

		// Draw a vertical line down the left side of each card
		for cy := cursor; cy < cursor+c.cards[ind].height; cy++ {
			screen.SetContent(xOffset, cy, vertLine, nil, style)
		}

		// Print the card's title
		for j := range c.cards[ind].wrappedTitle {
			tview.Print(
				screen,
				c.cards[ind].wrappedTitle[j],
				xOffset+2,
				cursor+j,
				width,
				tview.AlignLeft|tview.AlignTop,
				tcell.ColorGreen.TrueColor(),
			)
		}

		// Print the card's metadata
		cal := "📅"
		cardTextFmt := "#%d %s%s"

		tview.Print(
			screen,
			fmt.Sprintf(cardTextFmt, c.cards[ind].id, cal, c.cards[ind].created),
			xOffset+2,
			cursor+len(c.cards[ind].wrappedTitle),
			width,
			tview.AlignLeft|tview.AlignTop,
			tcell.ColorGrey.TrueColor(),
		)

		cursor = cursor + c.cards[ind].height + gap
	}

	// draw a 'placeholder card' if in status selection board mode
	if mode == selection && c.HasFocus() {
		vertLine := tview.BoxDrawingsHeavyVertical
		style := tcell.StyleDefault.Foreground(tcell.ColorWhite.TrueColor())

		for cy := cursor; cy < cursor+1; cy++ {
			screen.SetContent(xOffset, cy, vertLine, nil, style)
		}

		tview.Print(
			screen,
			"Move the card to this column",
			xOffset+2,
			cursor,
			width,
			tview.AlignLeft|tview.AlignTop,
			tcell.ColorWhite.TrueColor(),
		)
	}
}