package action

import (
	"fmt"
	"strings"

	tea "github.com/charmbracelet/bubbletea"
)

// Paste implements Action (p) - pastes after cursor
type Paste struct {
	Count int
}

func (a Paste) Execute(m Model) tea.Cmd {
	// Get reg
	reg, found := m.GetRegister('"')
	if !found {
		m.SetCommandError(fmt.Errorf("\"\" register is broken. Uh oh."))
		return nil
	}

	// Exit if blank
	if len(reg.Content) == 0 {
		return nil
	}

	switch reg.Type {
	case LinewiseRegister:
		{
			initY := m.CursorY()
			lines := reg.Content
			insertPos := initY + 1

			// Run count times
			for range a.Count {
				for _, line := range lines {
					m.InsertLine(insertPos, line)
					insertPos++
				}
			}

			if m.LineCount() > 1 {
				m.SetCursorY(initY + 1)
			}
		}
	case CharwiseRegister:
		{
			lines := reg.Content

			// Shouldn't happen, just a check
			if len(lines) != 1 {
				m.SetCommandError(fmt.Errorf("Charwise register should only have a single line of content."))
				break
			}

			x := m.CursorX()
			y := m.CursorY()

			cnt := strings.Repeat(lines[0], max(1, a.Count))
			curLine := m.Line(y)

			// Catch edge cases, end of line, start of blank line
			insertAt := min(x+1, len(curLine))
			newLine := curLine[:insertAt] + cnt + curLine[insertAt:]
			m.SetLine(y, newLine)

			m.SetCursorX(x + len(cnt))
			m.ClampCursorX()
		}
	default:
		m.SetCommandError(fmt.Errorf("Register type is not implemented."))
	}

	return nil
}

// Ensure Paste implements Repeatable
var _ Repeatable = Paste{}

func (a Paste) WithCount(n int) Action {
	return Paste{Count: n}
}

// PasteBefore implements Action (P) - pastes before cursor
type PasteBefore struct {
	Count int
}

func (a PasteBefore) Execute(m Model) tea.Cmd {
	// Get reg
	reg, found := m.GetRegister('"')
	if !found {
		m.SetCommandError(fmt.Errorf("\"\" register is broken. Uh oh."))
		return nil
	}

	switch reg.Type {
	case LinewiseRegister:
		{
			initY := m.CursorY()
			lines := reg.Content
			insertPos := initY // Leave here, this will effectively move the lines below

			// Run count times
			for range a.Count {
				for _, line := range lines {
					m.InsertLine(insertPos, line)
					insertPos++
				}
			}
		}
	case CharwiseRegister:
		{
			lines := reg.Content

			// Shouldn't happen, just a check
			if len(lines) != 1 {
				m.SetCommandError(fmt.Errorf("Charwise register should only have a single line of content."))
				break
			}

			x := m.CursorX()
			y := m.CursorY()

			cnt := strings.Repeat(lines[0], max(1, a.Count))
			curLine := m.Line(y)

			// Catch edge cases, end of line, start of blank line
			insertAt := min(x, len(curLine))
			newLine := curLine[:insertAt] + cnt + curLine[insertAt:]
			m.SetLine(y, newLine)

			m.SetCursorX(x + len(cnt))
			m.ClampCursorX()
		}
	default:
		m.SetCommandError(fmt.Errorf("Register type is not implemented."))
	}

	return nil
}

// Ensure PasteBefore implements Repeatable
var _ Repeatable = PasteBefore{}

func (a PasteBefore) WithCount(n int) Action {
	return PasteBefore{Count: n}
}