package action

import (
	"strings"

	tea "github.com/charmbracelet/bubbletea"
)

type JoinLines struct {
	Preserve bool
	Count    int
}

// WithCount sets the count (required by Repeatable interface)
func (m JoinLines) WithCount(n int) Action {
	m.Count = n
	return m
}

func (a JoinLines) Execute(m Model) tea.Cmd {
	win := m.ActiveWindow()
	buf := m.ActiveBuffer()

	y := win.Cursor.Line

	var line strings.Builder
	line.WriteString(buf.Line(y))
	spacePending := false

	for range max(1, a.Count-1) {
		if (y + 1) >= buf.LineCount() {
			break
		}

		l := buf.Line(y + 1)

		if a.Preserve {
			line.WriteString(l)
		} else {
			l = strings.TrimLeft(l, " ")
			if l == "" {
				spacePending = true
			} else {
				line.WriteString(" " + l)
				spacePending = false
			}
		}

		buf.DeleteLine(y + 1)
	}

	if !a.Preserve && spacePending {
		line.WriteString(" ")
	}

	if line.String() != buf.Line(y) {
		buf.SetLine(y, line.String())
	}
	return nil
}