//go:build js && wasm

package main

import (
	"bytes"
	"syscall/js"

	"git.taurusxin.com/taurusxin/ncmdump-go/ncmcrypt"
)

func convertNcm(this js.Value, args []js.Value) interface{} {
	if len(args) < 1 {
		return errorResult("no data provided")
	}

	dataLen := args[0].Get("byteLength").Int()
	if dataLen == 0 {
		return errorResult("empty data")
	}

	data := make([]byte, dataLen)
	js.CopyBytesToGo(data, args[0])

	ncm, err := ncmcrypt.NewNeteaseCloudMusicFromBytes(data)
	if err != nil {
		return errorResult(err.Error())
	}
	defer ncm.Close()

	var buf bytes.Buffer
	if err := ncm.DumpStream(&buf, nil); err != nil {
		return errorResult(err.Error())
	}

	format := ncm.GetFormat()
	result := js.Global().Get("Uint8Array").New(js.ValueOf(buf.Len()))
	js.CopyBytesToJS(result, buf.Bytes())

	meta := ncm.GetMetadata()

	return js.ValueOf(map[string]interface{}{
		"data":     result,
		"format":   format,
		"title":    meta["title"],
		"artist":   meta["artist"],
		"album":    meta["album"],
		"coverUrl": meta["coverUrl"],
	})
}

func embedMetadata(this js.Value, args []js.Value) interface{} {
	if len(args) < 2 {
		return errorResult("insufficient arguments")
	}

	audioLen := args[0].Get("byteLength").Int()
	audio := make([]byte, audioLen)
	js.CopyBytesToGo(audio, args[0])

	format := args[1].String()
	title := ""
	artist := ""
	album := ""
	var coverData []byte

	if len(args) > 2 && args[2].Type() == js.TypeObject {
		opts := args[2]
		if v := opts.Get("title"); v.Type() == js.TypeString {
			title = v.String()
		}
		if v := opts.Get("artist"); v.Type() == js.TypeString {
			artist = v.String()
		}
		if v := opts.Get("album"); v.Type() == js.TypeString {
			album = v.String()
		}
		if v := opts.Get("coverData"); v.Type() != js.TypeUndefined && v.Type() != js.TypeNull {
			coverLen := v.Get("byteLength").Int()
			coverData = make([]byte, coverLen)
			js.CopyBytesToGo(coverData, v)
		}
	}

	result, err := ncmcrypt.EmbedMetadata(audio, format, title, artist, album, coverData)
	if err != nil {
		return errorResult(err.Error())
	}

	out := js.Global().Get("Uint8Array").New(js.ValueOf(len(result)))
	js.CopyBytesToJS(out, result)
	return js.ValueOf(map[string]interface{}{
		"data":   out,
		"format": format,
	})
}

func errorResult(msg string) js.Value {
	return js.ValueOf(map[string]interface{}{
		"error": msg,
	})
}

func main() {
	js.Global().Set("ncmdumpConvert", js.FuncOf(convertNcm))
	js.Global().Set("ncmdumpEmbed", js.FuncOf(embedMetadata))

	ready := js.Global().Get("ncmdumpOnReady")
	if ready.Type() == js.TypeFunction {
		ready.Invoke()
	}

	select {}
}