package engine

import (
	"path"
	"strings"

	"aiaa-notification-service/internal/model"
)

// PickEventRule selects the best enabled rule for an event.
// Exact event wins; otherwise glob patterns (* and ?) via path.Match.
// Among globs, more literal characters win; ties go to the smaller ID.
func PickEventRule(event string, rules []model.Rule) *model.Rule {
	picked := PickEventRules(event, rules)
	if len(picked) == 0 {
		return nil
	}
	best := &picked[0]
	for i := range picked[1:] {
		if picked[i+1].ID < best.ID {
			best = &picked[i+1]
		}
	}
	return best
}

// PickEventRules returns every enabled rule at the winning specificity.
// All exact event matches win as a group; otherwise all globs that share
// the highest literal-character score.
func PickEventRules(event string, rules []model.Rule) []model.Rule {
	var exact []model.Rule
	var globs []model.Rule
	bestScore := -1
	for i := range rules {
		r := rules[i]
		if r.Enabled == 0 {
			continue
		}
		if r.Event == event {
			exact = append(exact, r)
			continue
		}
		if !strings.ContainsAny(r.Event, "*?") {
			continue
		}
		ok, err := path.Match(r.Event, event)
		if err != nil || !ok {
			continue
		}
		score := globSpecificity(r.Event)
		if score > bestScore {
			bestScore = score
			globs = []model.Rule{r}
			continue
		}
		if score == bestScore {
			globs = append(globs, r)
		}
	}
	if len(exact) > 0 {
		return exact
	}
	return globs
}

func globSpecificity(pattern string) int {
	n := 0
	for _, r := range pattern {
		if r != '*' && r != '?' {
			n++
		}
	}
	return n
}