package db

import (
	"encoding/json"
	"fmt"
	"gestion/models"
	"log"
	"math"
)

// FindLeastLoadedDeliveryman trouve le livreur avec le moins de commandes ET qui peut accepter
func (d *Database) FindLeastLoadedDeliveryman() (string, error) {
	keys, err := Redis.Keys(RedisCtx, "delivery:status:*").Result()
	if err != nil || len(keys) == 0 {
		return "", fmt.Errorf("aucun livreur trouvé")
	}

	var leastLoaded string
	minQueueSize := int64(MAX_COMMANDS_PER_DELIVERYMAN + 1)

	for _, key := range keys {
		username := key[len("delivery:status:"):]

		data, err := Redis.Get(RedisCtx, key).Result()
		if err != nil {
			continue
		}

		var status models.DeliveryPersonStatus
		json.Unmarshal([]byte(data), &status)

		if status.Status == "offline" {
			continue
		}

		// ✅ NOUVEAU: Vérifier si le livreur peut accepter des commandes
		if !d.CanDeliverymanAcceptCommands(username) {
			log.Printf("⏭️ [LEAST_LOADED] Skip %s: ne peut pas accepter", username)
			continue
		}

		queueKey := fmt.Sprintf("queue:deliveryman:%s", username)
		queueSize, _ := Redis.ZCard(RedisCtx, queueKey).Result()

		// Priorité aux livreurs disponibles (bonus de -1000)
		effectiveQueueSize := queueSize
		if status.Status == "available" {
			effectiveQueueSize -= 1000
		}

		if effectiveQueueSize < minQueueSize {
			minQueueSize = effectiveQueueSize
			leastLoaded = username
		}
	}

	if leastLoaded == "" {
		return "", fmt.Errorf("aucun livreur disponible")
	}

	queueKey := fmt.Sprintf("queue:deliveryman:%s", leastLoaded)
	actualQueueSize, _ := Redis.ZCard(RedisCtx, queueKey).Result()

	log.Printf("🎯 [LEAST_LOADED] %s sélectionné (%d/10 commandes)",
		leastLoaded, actualQueueSize)

	return leastLoaded, nil
}

// FindAvailableOrLeastLoadedDeliveryman trouve un livreur disponible ou le moins chargé
func (d *Database) FindAvailableOrLeastLoadedDeliveryman() (string, string, int, error) {
	keys, err := Redis.Keys(RedisCtx, "delivery:status:*").Result()
	if err != nil || len(keys) == 0 {
		return "", "", 0, fmt.Errorf("aucun livreur trouvé")
	}

	var bestDeliveryman string
	var bestStatus string
	bestQueueSize := int64(MAX_COMMANDS_PER_DELIVERYMAN + 1)

	for _, key := range keys {
		username := key[len("delivery:status:"):]

		data, err := Redis.Get(RedisCtx, key).Result()
		if err != nil {
			continue
		}

		var status models.DeliveryPersonStatus
		json.Unmarshal([]byte(data), &status)

		if status.Status == "offline" {
			continue
		}

		if !d.CanDeliverymanAcceptCommands(username) {
			continue
		}

		queueKey := fmt.Sprintf("queue:deliveryman:%s", username)
		queueSize, _ := Redis.ZCard(RedisCtx, queueKey).Result()

		if status.Status == "available" && queueSize == 0 {
			return username, "available", 0, nil
		}

		if queueSize < bestQueueSize {
			bestQueueSize = queueSize
			bestDeliveryman = username
			bestStatus = status.Status
		}
	}

	if bestDeliveryman == "" {
		return "", "", 0, fmt.Errorf("tous les livreurs sont au maximum de leur capacité")
	}

	return bestDeliveryman, bestStatus, int(bestQueueSize), nil
}

// GetLeastLoadedDeliverymanForced retourne le livreur avec le moins de commandes (SANS limite)
func (d *Database) GetLeastLoadedDeliverymanForced() (string, int64, error) {
	activeUsernames, err := d.GetAllActiveDeliverymenUsernames()
	if err != nil || len(activeUsernames) == 0 {
		return "", 0, fmt.Errorf("aucun livreur actif")
	}

	var leastLoaded string
	var minQueueSize int64 = math.MaxInt64

	for _, username := range activeUsernames {
		queueKey := fmt.Sprintf("queue:deliveryman:%s", username)
		queueSize, _ := Redis.ZCard(RedisCtx, queueKey).Result()

		if queueSize < minQueueSize {
			minQueueSize = queueSize
			leastLoaded = username
		}
	}

	return leastLoaded, minQueueSize, nil
}

// AreAllDeliverymenAtCapacity vérifie si tous les livreurs ont atteint leur capacité max
func (d *Database) AreAllDeliverymenAtCapacity() (bool, int, error) {
	activeUsernames, err := d.GetAllActiveDeliverymenUsernames()
	if err != nil || len(activeUsernames) == 0 {
		return false, 0, fmt.Errorf("aucun livreur actif")
	}

	if len(activeUsernames) == 1 {
		return false, 1, nil
	}

	atCapacityCount := 0
	for _, username := range activeUsernames {
		if !d.CanDeliverymanAcceptCommands(username) {
			atCapacityCount++
		}
	}

	allAtCapacity := atCapacityCount == len(activeUsernames)

	if allAtCapacity {
		log.Printf("🔴 [CAPACITY] TOUS les livreurs sont à capacité maximale (%d/%d)",
			atCapacityCount, len(activeUsernames))
	}

	return allAtCapacity, len(activeUsernames), nil
}