package editor

import (
	"bufio"
	"log"
	"os"
)

type document struct {
	dirty    bool
	filename string
	rows     []*row
}

func newDocument() *document {
	var rows []*row

	return &document{
		false,
		"",
		rows,
	}
}

func (d *document) open(filename string) {
	file, err := os.Open(filename)
	if err != nil {
		log.Fatalf("failed to open file")
	}
	defer file.Close()

	d.filename = filename
	scanner := bufio.NewScanner(file)
	scanner.Split(bufio.ScanLines)

	for scanner.Scan() {
		d.appendRow(scanner.Text())
	}
}

func (d *document) save() int {
	if d.filename == "" {
		return 0
	}

	file, err := os.OpenFile(d.filename, os.O_RDWR|os.O_CREATE, 0644)
	if err != nil {
		panic("failed to open/create file for saving")
	}
	defer file.Close()

	fileStr := d.toString()
	fileLen := len(fileStr)

	err = file.Truncate(int64(fileLen))
	if err != nil {
		panic("failed to truncate file")
	}

	size, err := file.WriteString(fileStr)

	if err != nil {
		panic("failed to save document to file")
	}

	if fileLen == size {
		return size
	}

	return 0
}

func (d *document) appendRow(s string) {
	newRow := newRow(s)
	newRow.update()
	d.rows = append(d.rows, newRow)
}

func (d *document) toString() string {
	buf := newBuffer()

	for _, row := range d.rows {
		buf.append(row.toString())
		buf.appendRune('\n')
	}

	return buf.toString()
}

func (d *document) rowCount() int {
	return len(d.rows)
}