package main

import (
	"code.squareroundforest.org/arpio/treerack"
	"errors"
	"io"
	"os"
)

type checkOptions struct {

	// Syntax specifies the filename of the syntax definition file.
	Syntax *string

	// SyntaxString specifies the syntax as an inline string.
	SyntaxString *string

	// Input specifies the filename of the input content to be validated.
	Input *string

	// InputString specifies the input content as an inline string.
	InputString *string

	// MaxTraceLength enables tracing when set to a positive integer.
	MaxTraceLength int
}

// check parses input content against the provided syntax definition and fails if the input does not match.
// Syntax can be provided via a filename option or an inline string option. Input can be provided via a filename
// option, a positional argument filename, an inline string option, or piped from standard input.
func check(o checkOptions, stdin io.Reader, args ...string) error {
	syntax, finalizeSyntax, err := initInput(o.Syntax, o.SyntaxString, nil, nil)
	if err != nil {
		return err
	}

	defer finalizeSyntax()
	input, finalizeInput, err := initInput(o.Input, o.InputString, stdin, args)
	if err != nil {
		return err
	}

	defer finalizeInput()
	s := &treerack.Syntax{MaxTraceLength: o.MaxTraceLength}
	if err := s.ReadSyntax(syntax); err != nil {
		if terr := treerack.Trace(os.Stderr, err); terr != nil {
			err = errors.Join(err, terr)
		}

		return err
	}

	if err := s.Init(); err != nil {
		return err
	}

	if _, err := s.Parse(input); err != nil {
		if terr := treerack.Trace(os.Stderr, err); terr != nil {
			err = errors.Join(err, terr)
		}

		return err
	}

	return nil
}