package uci

import (
	"os"

	"github.com/alecthomas/participle/v2"
	"github.com/alecthomas/participle/v2/lexer"
	"github.com/pkg/errors"
)

var (
	uciLexer = lexer.MustSimple([]lexer.SimpleRule{
		{Name: `Ident`, Pattern: `[a-zA-Z][a-zA-Z\d_\-]*`},
		{Name: `String`, Pattern: `'([^'])*'`},
		{Name: "whitespace", Pattern: `\s+`},
	})
	parser = participle.MustBuild[UCI](
		participle.Lexer(uciLexer),
		participle.Unquote("String"),
	)
)

type Parser struct{}

func ParseFile(filename string) (*UCI, error) {
	file, err := os.Open(filename)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	defer func() {
		if err := file.Close(); err != nil {
			panic(errors.WithStack(err))
		}
	}()

	uci, err := parser.Parse(filename, file, participle.Trace(os.Stdout))
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return uci, nil
}

func Parse(data []byte) (*UCI, error) {
	uci, err := parser.ParseBytes("", data)
	if err != nil {
		return nil, errors.WithStack(err)
	}

	return uci, nil
}