// Command indexer walks an Einherjar repository checkout, parses every
// sibling module, and writes the resulting framework knowledge index to
// data/index.json (or the path given by -out).
//
// Usage:
//
//	go run ./cmd/indexer ..            # default output: data/index.json
//	go run ./cmd/indexer -out idx.json /path/to/einherjar
package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"os"

	"code.nochebuena.dev/einherjar/mcp/internal/index"
)

func main() {
	out := flag.String("out", "data/index.json", "output path for the generated index")
	flag.Usage = func() {
		fmt.Fprintf(os.Stderr, "usage: indexer [-out path] <einherjar-repo-root>\n")
		flag.PrintDefaults()
	}
	flag.Parse()

	root := flag.Arg(0)
	if root == "" {
		root = ".."
	}

	idx, err := index.Build(root)
	if err != nil {
		fmt.Fprintf(os.Stderr, "indexer: %v\n", err)
		os.Exit(1)
	}
	idx.Modules = append(idx.Modules, index.BuildBuiltins())

	f, err := os.Create(*out)
	if err != nil {
		fmt.Fprintf(os.Stderr, "indexer: %v\n", err)
		os.Exit(1)
	}
	defer f.Close()

	enc := json.NewEncoder(f)
	enc.SetIndent("", "  ")
	if err := enc.Encode(idx); err != nil {
		fmt.Fprintf(os.Stderr, "indexer: encode: %v\n", err)
		os.Exit(1)
	}

	fmt.Fprintf(os.Stderr, "indexer: wrote %s (%d modules)\n", *out, len(idx.Modules))
}