package grc20reg

import (
	"std"

	"gno.land/p/demo/avl"
	"gno.land/p/demo/avl/rotree"
	"gno.land/p/demo/fqname"
	"gno.land/p/demo/grc/grc20"
	"gno.land/p/demo/ufmt"
)

var registry = avl.NewTree() // rlmPath[.slug] -> TokenGetter (slug is optional)

func Register(tokenGetter grc20.TokenGetter, slug string) {
	rlmPath := std.PreviousRealm().PkgPath()
	key := fqname.Construct(rlmPath, slug)
	registry.Set(key, tokenGetter)
	std.Emit(
		registerEvent,
		"pkgpath", rlmPath,
		"slug", slug,
	)
}

func Get(key string) grc20.TokenGetter {
	tokenGetter, ok := registry.Get(key)
	if !ok {
		return nil
	}
	return tokenGetter.(grc20.TokenGetter)
}

func MustGet(key string) grc20.TokenGetter {
	tokenGetter := Get(key)
	if tokenGetter == nil {
		panic("unknown token: " + key)
	}
	return tokenGetter
}

func Render(path string) string {
	switch {
	case path == "": // home
		// TODO: add pagination
		s := ""
		count := 0
		registry.Iterate("", "", func(key string, tokenI any) bool {
			count++
			tokenGetter := tokenI.(grc20.TokenGetter)
			token := tokenGetter()
			rlmPath, slug := fqname.Parse(key)
			rlmLink := fqname.RenderLink(rlmPath, slug)
			infoLink := "/r/demo/grc20reg:" + key
			s += ufmt.Sprintf("- **%s** - %s - [info](%s)\n", token.GetName(), rlmLink, infoLink)
			return false
		})
		if count == 0 {
			return "No registered token."
		}
		return s
	default: // specific token
		key := path
		tokenGetter := MustGet(key)
		token := tokenGetter()
		rlmPath, slug := fqname.Parse(key)
		rlmLink := fqname.RenderLink(rlmPath, slug)
		s := ufmt.Sprintf("# %s\n", token.GetName())
		s += ufmt.Sprintf("- symbol: **%s**\n", token.GetSymbol())
		s += ufmt.Sprintf("- realm: %s\n", rlmLink)
		s += ufmt.Sprintf("- decimals: %d\n", token.GetDecimals())
		s += ufmt.Sprintf("- total supply: %d\n", token.TotalSupply())
		return s
	}
}

const registerEvent = "register"

func GetRegistry() *rotree.ReadOnlyTree {
	return rotree.Wrap(registry, nil)
}