package dbml

import (
	"regexp"
	"strings"

	"git.warky.dev/wdevs/relspecgo/pkg/models"
)

var (
	generatedNoteRegex = regexp.MustCompile(`(?is)^GENERATED\s+ALWAYS\s+AS\s*\((.*)\)\s*STORED$`)
	identityNoteRegex  = regexp.MustCompile(`(?i)^GENERATED\s+(ALWAYS|BY\s+DEFAULT)\s+AS\s+IDENTITY$`)
)

// applyColumnMarkerNote interprets a column note written by the DBML writer for
// GENERATED ... STORED and GENERATED ... AS IDENTITY columns, setting the matching
// model fields. It returns true when the note was a marker, in which case it is not
// a user comment.
func applyColumnMarkerNote(column *models.Column, rawNote string) bool {
	note := strings.TrimSpace(rawNote)
	if len(note) >= 2 && (note[0] == '\'' || note[0] == '"') && note[len(note)-1] == note[0] {
		note = note[1 : len(note)-1]
	}
	note = strings.ReplaceAll(strings.ReplaceAll(note, `\'`, `'`), `\\`, `\`)
	note = strings.TrimSpace(note)

	if m := generatedNoteRegex.FindStringSubmatch(note); m != nil {
		column.Generated = true
		column.GenerationExpression = strings.TrimSpace(m[1])
		return true
	}
	if m := identityNoteRegex.FindStringSubmatch(note); m != nil {
		column.Identity = true
		column.IdentityGeneration = strings.Join(strings.Fields(strings.ToUpper(m[1])), " ")
		return true
	}
	return false
}