//go:build !js

// Package main provides a build-time CLI for generating Web Component bundles.
// Reads a JSON slot map from stdin, writes the generated JS or TypeScript to stdout.
//
// Usage:
//
//	echo '{"H":"nav-bar","C":"main-content"}' | go run ./cmd/codegen/ > components.js
//	echo '{"H":"nav-bar","C":"main-content"}' | go run ./cmd/codegen/ -types > components.d.ts
package main

import (
	"flag"
	goio "io"
	"os"

	core "dappco.re/go/core"
	"dappco.re/go/core/html/codegen"
	coreio "dappco.re/go/core/io"
	log "dappco.re/go/core/log"
)

func run(r goio.Reader, w goio.Writer, emitTypes bool) error {
	data, err := goio.ReadAll(r)
	if err != nil {
		return log.E("codegen", "reading stdin", err)
	}

	var slots map[string]string
	if result := core.JSONUnmarshal(data, &slots); !result.OK {
		err, _ := result.Value.(error)
		return log.E("codegen", "invalid JSON", err)
	}

	out := ""
	if emitTypes {
		out = codegen.GenerateTypeScriptDefinitions(slots)
	} else {
		out, err = codegen.GenerateBundle(slots)
		if err != nil {
			return log.E("codegen", "generate bundle", err)
		}
	}

	_, err = goio.WriteString(w, out)
	if err != nil {
		return log.E("codegen", "writing output", err)
	}
	return nil
}

func main() {
	emitTypes := flag.Bool("types", false, "emit TypeScript declarations instead of JavaScript")
	flag.Parse()

	stdin, err := coreio.Local.Open("/dev/stdin")
	if err != nil {
		log.Error("failed to open stdin", "scope", "codegen.main", "err", log.E("codegen.main", "open stdin", err))
		os.Exit(1)
	}

	stdout, err := coreio.Local.Create("/dev/stdout")
	if err != nil {
		_ = stdin.Close()
		log.Error("failed to open stdout", "scope", "codegen.main", "err", log.E("codegen.main", "open stdout", err))
		os.Exit(1)
	}
	defer func() {
		_ = stdin.Close()
		_ = stdout.Close()
	}()

	if err := run(stdin, stdout, *emitTypes); err != nil {
		log.Error("codegen failed", "scope", "codegen.main", "err", err)
		os.Exit(1)
	}
}