package parser

import (
	"io/fs"

	"asciigoat.org/core/lexer"
)

// NewError creates a lexer.Error using a lexer.Position
func NewError(pos lexer.Position, content, hint string, err error) *lexer.Error {
	return &lexer.Error{
		Line:    pos.Line,
		Column:  pos.Column,
		Content: content,
		Hint:    hint,
		Err:     err,
	}
}

// ErrPlusPosition returns a copy of the given [lexer.Error]
// offsetting the Line/Column information.
func ErrPlusPosition(pos lexer.Position, e *lexer.Error) *lexer.Error {
	pos.Add(lexer.Position{
		Line:   e.Line,
		Column: e.Column,
	})

	return NewError(pos, e.Content, e.Hint, e.Err)
}

// NewErrIncompleteQuotedString returns a [lexer.Error]
// indicating the quoted string being parsed wasn't correctly
// terminated
func NewErrIncompleteQuotedString(p *TextParser) *lexer.Error {
	return newErrIncomplete(p, "incomplete quoted string")
}

// NewErrIncompleteEscaped returns a [lexer.Error]
// indicating the text being parsed wasn't correctly
// terminated
func NewErrIncompleteEscaped(p *TextParser) *lexer.Error {
	return newErrIncomplete(p, "incomplete escaped string")
}

func newErrIncomplete(p *TextParser, hint string) *lexer.Error {
	pos, s := p.Emit()
	pos.Add(GetPositionalLength(s))

	return NewError(pos, s, hint, fs.ErrInvalid)
}

// NewErrInvalidEscapeSequence returns a [lexer.Error] indicating
// the specified sequence, at the end of the accepted buffer,
// is invalid
func NewErrInvalidEscapeSequence(p *TextParser, seq string) *lexer.Error {
	pos, s := p.Position(), p.String()

	s = s[:len(s)-len(seq)]
	pos.Add(GetPositionalLength(s))

	return NewError(pos, seq, "invalid escape character", fs.ErrInvalid)
}