// License: GPLv3 Copyright: 2022, Kovid Goyal, <kovid at kovidgoyal.net>

package readline

import (
	"fmt"
	"strings"

	"kitty/tools/utils"
)

var _ = fmt.Print

func (self *Readline) text_upto_cursor_pos() string {
	buf := strings.Builder{}
	buf.Grow(1024)
	for i, line := range self.lines {
		if i == self.cursor_line {
			buf.WriteString(line[:self.cursor_pos_in_line])
			break
		} else {
			buf.WriteString(line)
			buf.WriteString("\n")
		}
	}
	return buf.String()
}

func (self *Readline) text_after_cursor_pos() string {
	buf := strings.Builder{}
	buf.Grow(1024)
	for i, line := range self.lines {
		if i == self.cursor_line {
			buf.WriteString(line[self.cursor_pos_in_line:])
			buf.WriteString("\n")
		} else if i > self.cursor_line {
			buf.WriteString(line)
			buf.WriteString("\n")
		}
	}
	ans := buf.String()
	ans = ans[:len(ans)-1]
	return ans
}

func (self *Readline) all_text() string {
	return strings.Join(self.lines, "\n")
}

func (self *Readline) add_text(text string) {
	new_lines := make([]string, 0, len(self.lines)+4)
	new_lines = append(new_lines, self.lines[:self.cursor_line]...)
	var lines_after []string
	if len(self.lines) > self.cursor_line+1 {
		lines_after = self.lines[self.cursor_line+1:]
	}
	has_trailing_newline := strings.HasSuffix(text, "\n")

	add_line_break := func(line string) {
		new_lines = append(new_lines, line)
		self.cursor_pos_in_line = len(line)
		self.cursor_line += 1
	}
	cline := self.lines[self.cursor_line]
	before_first_line := cline[:self.cursor_pos_in_line]
	after_first_line := ""
	if self.cursor_pos_in_line < len(cline) {
		after_first_line = cline[self.cursor_pos_in_line:]
	}
	for i, line := range utils.Splitlines(text) {
		if i > 0 {
			add_line_break(line)
		} else {
			line := before_first_line + line
			self.cursor_pos_in_line = len(line)
			new_lines = append(new_lines, line)
		}
	}
	if has_trailing_newline {
		add_line_break("")
	}
	if after_first_line != "" {
		if len(new_lines) == 0 {
			new_lines = append(new_lines, "")
		}
		new_lines[len(new_lines)-1] += after_first_line
	}
	if len(lines_after) > 0 {
		new_lines = append(new_lines, lines_after...)
	}
	self.lines = new_lines
}