package main

import (
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"

	"moria.us/macscript/charmap"
	"moria.us/macscript/table"
)

const header = "/* This file is automatically generated. */\n"

var (
	flagDest  string
	flagSrc   string
	flagQuiet bool
)

func getSrcdir() (string, error) {
	if flagSrc != "" {
		return flagSrc, nil
	}
	exe, err := os.Executable()
	if err != nil {
		return "", err
	}
	return filepath.Dir(filepath.Dir(exe)), nil
}

func mainE() error {
	srcdir, err := getSrcdir()
	if err != nil {
		return fmt.Errorf("could not find source dir: %v", err)
	}
	destdir := flagDest
	if destdir == "" {
		destdir = filepath.Join(srcdir, "src")
	}

	// Read metadata.
	d, err := readData(srcdir)
	if err != nil {
		return err
	}

	// Compile and emit charmap data.
	cms := make([]string, len(d.charmaps))
	var hascmap bool
	for i, c := range d.charmaps {
		if c.file == "" {
			continue
		}
		cm, err := charmap.ReadFile(filepath.Join(srcdir, "charmap", c.file))
		if err != nil {
			return err
		}
		t, err := table.Create(cm)
		if err != nil {
			if e, ok := err.(*table.UnsupportedError); ok {
				if !flagQuiet {
					fmt.Fprintf(os.Stderr, "Warning: unsupported charmap %q: %s\n", c.file, e.Message)
				}
				continue
			}
			return fmt.Errorf("%s: %v", c.file, err)
		}
		data := t.Data()
		name := "charmap_" + strings.ToLower(strings.TrimSuffix(c.file, ".TXT")) + ".dat"
		fpath := filepath.Join(destdir, name)
		if !flagQuiet {
			fmt.Fprintln(os.Stderr, "Writing:", fpath)
		}
		if err := ioutil.WriteFile(fpath, data, 0666); err != nil {
			return err
		}
		cms[i] = name
		hascmap = true
	}
	if !hascmap {
		return errors.New("could not compile any character map")
	}

	// Write generated output.
	m := genMap(&d)
	if err := writeMap(&d, m, filepath.Join(destdir, "charmap.c")); err != nil {
		return err
	}
	if err := writeRez(&d, cms, filepath.Join(destdir, "charmap.r")); err != nil {
		return err
	}
	return nil
}

func main() {
	flag.StringVar(&flagDest, "dest", "", "output directory")
	flag.StringVar(&flagSrc, "src", "", "source directory")
	flag.BoolVar(&flagQuiet, "quiet", false, "only output error messages")
	flag.Parse()
	if args := flag.Args(); len(args) != 0 {
		fmt.Fprintf(os.Stderr, "Error: unexpected argument: %q\n", args[0])
		os.Exit(2)
	}
	if err := mainE(); err != nil {
		fmt.Fprintln(os.Stderr, "Error:", err)
		os.Exit(1)
	}
}