package parser

import "git.tebibyte.media/sashakoshka/arf/file"
import "git.tebibyte.media/sashakoshka/arf/types"
import "git.tebibyte.media/sashakoshka/arf/lexer"

// parseData parses a data section.
func (parser *ParsingOperation) parseDataSection () (
	section *DataSection,
	err     error,
) {
	err = parser.expect(lexer.TokenKindName)
	if err != nil { return }
	
	section = &DataSection { location: parser.token.Location() }

	err = parser.nextToken(lexer.TokenKindPermission)
	if err != nil { return }
	section.permission = parser.token.Value().(types.Permission)

	err = parser.nextToken(lexer.TokenKindName)
	if err != nil { return }
	section.name = parser.token.Value().(string)

	err = parser.nextToken(lexer.TokenKindColon)
	if err != nil { return }
	section.what, err = parser.parseType()
	if err != nil { return }

	return
}

// parseType parses a type notation of the form Name, {Name}, etc.
func (parser *ParsingOperation) parseType () (what Type, err error) {
	err = parser.nextToken(lexer.TokenKindName, lexer.TokenKindLBrace)
	if err != nil { return }
	what.location = parser.token.Location()

	if parser.token.Is(lexer.TokenKindLBrace) {
		what.kind = TypeKindPointer
	
		var points Type
		points, err = parser.parseType()
		if err != nil { return }
		what.points = &points

		err = parser.nextToken (
			lexer.TokenKindUInt,
			lexer.TokenKindRBrace)
		if err != nil { return }

		if parser.token.Is(lexer.TokenKindUInt) {
			what.kind = TypeKindArray
		
			what.length = parser.token.Value().(uint64)
		
			err = parser.nextToken (
				lexer.TokenKindUInt,
				lexer.TokenKindRBrace)
			if err != nil { return }
		}
	} else {
		what.name, err = parser.parseIdentifier()
		if err != nil { return }
	}

	err = parser.nextToken()

	if parser.token.Is(lexer.TokenKindColon) {
		err = parser.nextToken(lexer.TokenKindName)
		if err != nil { return }

		qualifier := parser.token.Value().(string)
		switch qualifier {
		case "mut":
			what.mutable = true
		default:
			err = parser.token.NewError (
				"unknown type qualifier \"" + qualifier + "\"",
				file.ErrorKindError)
			return
		}
	}

	return
}

// parseIdentifier parses an identifier made out of dot separated names.
func (parser *ParsingOperation) parseIdentifier () (
	identifier Identifier,
	err        error,
) {
	err = parser.expect(lexer.TokenKindName)
	if err != nil { return }
	identifier.location = parser.token.Location()

	for {
		if !parser.token.Is(lexer.TokenKindName) { break }

		identifier.trail = append (
			identifier.trail,
			parser.token.Value().(string))

		err = parser.nextToken()
		if err != nil { return }
		
		if !parser.token.Is(lexer.TokenKindDot) { break }
	}

	return
}