// dump2png converts the raw indexed-pixel frame dumps written by the
// engine's debug dump hotkey (see ../engine-patches/ and the root
// README.md's "Debugging" section) into viewable PNGs, using the real game
// palette - see that same README section for the dump file format.
package main

import (
	"encoding/binary"
	"fmt"
	"image"
	"image/color"
	"image/png"
	"os"
	"path/filepath"
	"sort"
	"strings"

	"github.com/inkyblackness/hacked/ss1/content/bitmap"
	"github.com/inkyblackness/hacked/ss1/resource"
	"github.com/inkyblackness/hacked/ss1/world"
)

func main() {
	if len(os.Args) != 4 {
		fmt.Fprintln(os.Stderr, "usage: dump2png <game-data-dir> <dumps-dir> <out-dir>")
		os.Exit(1)
	}
	dataDir, inDir, outDir := os.Args[1], os.Args[2], os.Args[3]

	entries, err := os.ReadDir(dataDir)
	if err != nil {
		panic(err)
	}
	merged := &world.ManifestEntry{Origin: []string{dataDir}, ID: dataDir}
	for _, e := range entries {
		if e.IsDir() {
			continue
		}
		ext := strings.ToLower(filepath.Ext(e.Name()))
		if ext != ".res" && ext != ".dat" {
			continue
		}
		fe, err := world.NewManifestEntryFrom([]string{filepath.Join(dataDir, e.Name())})
		if err != nil {
			continue
		}
		merged.Resources = append(merged.Resources, fe.Resources...)
	}
	sort.Slice(merged.Resources, func(i, j int) bool { return merged.Resources[i].ID < merged.Resources[j].ID })
	mod := world.NewMod(func([]resource.ID, []resource.ID) {}, func() {})
	if err := mod.World().InsertEntry(0, merged); err != nil {
		panic(err)
	}
	pal, err := bitmap.NewPaletteCache(mod).Palette(resource.KeyOf(0x02BC, resource.LangDefault, 0))
	if err != nil {
		panic(err)
	}
	colors := pal.ColorPalette(false)

	if err := os.MkdirAll(outDir, 0o755); err != nil {
		panic(err)
	}
	files, err := os.ReadDir(inDir)
	if err != nil {
		panic(err)
	}
	for _, fi := range files {
		if !strings.HasSuffix(fi.Name(), ".raw") {
			continue
		}
		raw, err := os.ReadFile(filepath.Join(inDir, fi.Name()))
		if err != nil {
			fmt.Println("skip", fi.Name(), err)
			continue
		}
		if len(raw) < 4 {
			continue
		}
		w := int(binary.LittleEndian.Uint16(raw[0:2]))
		h := int(binary.LittleEndian.Uint16(raw[2:4]))
		pixels := raw[4:]
		if len(pixels) < w*h {
			fmt.Println("truncated", fi.Name())
			continue
		}
		img := image.NewRGBA(image.Rect(0, 0, w, h))
		for i := 0; i < w*h; i++ {
			r, g, b, _ := colors[pixels[i]].RGBA()
			img.Set(i%w, i/w, color.RGBA{R: byte(r >> 8), G: byte(g >> 8), B: byte(b >> 8), A: 0xff})
		}
		outPath := filepath.Join(outDir, strings.TrimSuffix(fi.Name(), ".raw")+".png")
		of, err := os.Create(outPath)
		if err != nil {
			fmt.Println("create failed", outPath, err)
			continue
		}
		err = png.Encode(of, img)
		of.Close()
		if err != nil {
			fmt.Println("encode failed", outPath, err)
			continue
		}
		fmt.Println("wrote", outPath, w, h)
	}
}