package main

import (
	"fmt"
	"io/ioutil"
	"os"
	"os/user"
	"path/filepath"
	"strconv"
	"strings"
)

const (
	Sheet   rune = 29
	Row     rune = 30
	Field   rune = 31
	End     rune = 3
	ModSep  rune = 26
)

func WriteFile(path string) {
	f, err := os.Create(path)
	if err != nil {
		panic(err.Error())
	}
	defer f.Close()
	f.WriteString("tss")
	for _, s := range wb.sheets {
		writeSheet(f, s)
	}
	f.WriteString(string(End))
}

func writeSheet(f *os.File, sh sheet) {
	var o strings.Builder
	o.WriteRune(Sheet)

	// Sheet header data
	fmt.Fprintf(&o, "%s%c%d%c%d%c%d", sh.name, Field, sh.cols, Field, sh.rows, Field, sh.zoom)
	for _, row := range sh.cells {
		o.WriteRune(Row)
		for c, cell := range row {
			o.WriteString(cell.rawVal)
			o.WriteRune(26)
			modstr := make([]string, len(cell.mods))
			for _, modint := range cell.mods {
				ms := strconv.Itoa(modint)
				modstr = append(modstr, ms)
			}
			o.WriteString(strings.Join(modstr, ","))
			if c < len(row) - 1 {
				o.WriteRune(Field)
			}
		}
	}
	f.WriteString(o.String())
}

func LoadFile(path string) {
	fbytes, err := ioutil.ReadFile(path)
	if err != nil {
		fmt.Fprint(os.Stderr, "Unable to read file\n")
		os.Exit(1)
	}
	f := string(fbytes)
	if !strings.HasPrefix(f, "tss") || !strings.HasSuffix(f, string(End)) {
		fmt.Fprint(os.Stderr, "Invalid file type\n")
		os.Exit(1)
	}
	wb = makeWorkbook(path)
	wb.sheets = make([]sheet, 0, 2)
	sheets := strings.Split(f[4:len(f)-1], fmt.Sprintf("%c", Sheet))
	for _, sh := range sheets {
		if len(sh) == 0 {
			continue
		}
		rows := strings.Split(sh, fmt.Sprintf("%c", Row))
		if len(rows) < 1 {
			return
		}
		s := makeSheet("")
		sfields := strings.Split(rows[0], fmt.Sprintf("%c", Field))
		s.name = sfields[0]
		s.cols, _ = strconv.Atoi(sfields[1])
		s.rows, _ = strconv.Atoi(sfields[2])
		s.zoom, _ = strconv.Atoi(sfields[3])
		s.cells = make([][]cell, s.rows)

		for i, row := range rows[1:] {
			fields := strings.Split(row, fmt.Sprintf("%c", Field))
			s.cells[i] = make([]cell, s.cols)
			for x, field := range fields {
				rawValModSep := strings.Split(field, fmt.Sprintf("%c", ModSep))
				c := cell{}
				c.Update(rawValModSep[0])
				if len(rawValModSep) > 1 {
					for _, mod := range strings.Split(rawValModSep[1], ",") {
						modint, err := strconv.Atoi(mod)
						if err != nil {
							continue
						}
						c.ToggleMod(modint)
					}
				}
				s.cells[i][x] = c
			}
		}
		wb.sheets = append(wb.sheets, s)
	}
}

func ExpandedAbsFilepath(p string) string {
	if strings.HasPrefix(p, "~/") {
		usr, _ := user.Current()
		homedir := usr.HomeDir
		p = filepath.Join(homedir, p[2:])
	}

	path, _ := filepath.Abs(p)
	return path
}