package genji

import (
	"errors"
	"fmt"
	"strings"

	"github.com/asdine/genji/internal/scanner"
)

var (
	// ErrTableNotFound is returned when the targeted table doesn't exist.
	ErrTableNotFound = errors.New("table not found")

	// ErrTableAlreadyExists is returned when attempting to create a table with the
	// same name as an existing one.
	ErrTableAlreadyExists = errors.New("table already exists")

	// ErrIndexNotFound is returned when the targeted index doesn't exist.
	ErrIndexNotFound = errors.New("index not found")

	// ErrIndexAlreadyExists is returned when attempting to create an index with the
	// same name as an existing one.
	ErrIndexAlreadyExists = errors.New("index already exists")

	// ErrRecordNotFound is returned when no record is associated with the provided key.
	ErrRecordNotFound = errors.New("record not found")

	// ErrDuplicateRecord is returned when another record is already associated with a given key, primary key,
	// or if there is a unique index violation.
	ErrDuplicateRecord = errors.New("duplicate record")
)

// ParseError represents an error that occurred during parsing.
type ParseError struct {
	Message  string
	Found    string
	Expected []string
	Pos      scanner.Pos
}

// newParseError returns a new instance of ParseError.
func newParseError(found string, expected []string, pos scanner.Pos) *ParseError {
	return &ParseError{Found: found, Expected: expected, Pos: pos}
}

// Error returns the string representation of the error.
func (e *ParseError) Error() string {
	if e.Message != "" {
		return fmt.Sprintf("%s at line %d, char %d", e.Message, e.Pos.Line+1, e.Pos.Char+1)
	}
	return fmt.Sprintf("found %s, expected %s at line %d, char %d", e.Found, strings.Join(e.Expected, ", "), e.Pos.Line+1, e.Pos.Char+1)
}