package router

import (
	"context"
	"regexp"
	"sort"

	"github.com/paramah/gw_telegram/internal/domain/apperror"
	"github.com/paramah/gw_telegram/internal/domain/entity"
)

type Rule struct {
	Pattern    *regexp.Regexp
	IntentName string
	Target     entity.RouteTarget
	Priority   int
}

type RuleBasedRouter struct {
	rules []Rule
}

func NewRuleBasedRouter(rules []Rule) *RuleBasedRouter {
	sorted := make([]Rule, len(rules))
	copy(sorted, rules)
	sort.Slice(sorted, func(i, j int) bool {
		return sorted[i].Priority > sorted[j].Priority
	})
	return &RuleBasedRouter{rules: sorted}
}

func (r *RuleBasedRouter) Route(_ context.Context, msg entity.Message) (entity.Route, error) {
	for _, rule := range r.rules {
		if rule.Pattern.MatchString(msg.Text) {
			return entity.Route{
				Pattern:    rule.Pattern.String(),
				IntentName: rule.IntentName,
				Target:     rule.Target,
				Priority:   rule.Priority,
			}, nil
		}
	}
	return entity.Route{}, apperror.ErrRouteNotFound
}