package repository

import (
	"context"
	"strings"

	"haixun-backend/internal/library/clock"
	app "haixun-backend/internal/library/errors"
	"haixun-backend/internal/library/errors/code"
	"haixun-backend/internal/model/copy_mission/domain/entity"
	domrepo "haixun-backend/internal/model/copy_mission/domain/repository"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type mongoRepository struct {
	collection *mongo.Collection
}

func NewMongoRepository(db *mongo.Database) domrepo.Repository {
	if db == nil {
		return &mongoRepository{}
	}
	return &mongoRepository{collection: db.Collection(entity.CollectionName)}
}

func (r *mongoRepository) EnsureIndexes(ctx context.Context) error {
	if r.collection == nil {
		return nil
	}
	_, err := r.collection.Indexes().CreateMany(ctx, []mongo.IndexModel{
		{Keys: bson.D{{Key: "tenant_id", Value: 1}, {Key: "owner_uid", Value: 1}, {Key: "persona_id", Value: 1}, {Key: "update_at", Value: -1}}},
		{Keys: bson.D{{Key: "tenant_id", Value: 1}, {Key: "owner_uid", Value: 1}, {Key: "persona_id", Value: 1}, {Key: "_id", Value: 1}}, Options: options.Index().SetUnique(true)},
	})
	return err
}

func (r *mongoRepository) Create(ctx context.Context, mission *entity.Mission) (*entity.Mission, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	now := clock.NowUnixNano()
	mission.CreateAt = now
	mission.UpdateAt = now
	if mission.Status == "" {
		mission.Status = entity.StatusOpen
	}
	_, err := r.collection.InsertOne(ctx, mission)
	if err != nil {
		return nil, err
	}
	return mission, nil
}

func (r *mongoRepository) FindByID(ctx context.Context, tenantID, ownerUID, personaID, missionID string) (*entity.Mission, error) {
	return r.findOne(ctx, bson.M{
		"_id":        strings.TrimSpace(missionID),
		"tenant_id":  tenantID,
		"owner_uid":  ownerUID,
		"persona_id": strings.TrimSpace(personaID),
		"status":     bson.M{"$ne": entity.StatusDeleted},
	})
}

func (r *mongoRepository) ListByPersona(ctx context.Context, tenantID, ownerUID, personaID string) ([]*entity.Mission, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	cursor, err := r.collection.Find(
		ctx,
		bson.M{
			"tenant_id":  tenantID,
			"owner_uid":  ownerUID,
			"persona_id": strings.TrimSpace(personaID),
			"status":     bson.M{"$ne": entity.StatusDeleted},
		},
		options.Find().SetSort(bson.D{{Key: "update_at", Value: -1}}),
	)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)
	var items []*entity.Mission
	if err := cursor.All(ctx, &items); err != nil {
		return nil, err
	}
	return items, nil
}

func (r *mongoRepository) Update(ctx context.Context, tenantID, ownerUID, personaID, missionID string, patch map[string]interface{}) (*entity.Mission, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	if len(patch) == 0 {
		return r.FindByID(ctx, tenantID, ownerUID, personaID, missionID)
	}
	patch["update_at"] = clock.NowUnixNano()
	var out entity.Mission
	err := r.collection.FindOneAndUpdate(
		ctx,
		bson.M{
			"_id":        strings.TrimSpace(missionID),
			"tenant_id":  tenantID,
			"owner_uid":  ownerUID,
			"persona_id": strings.TrimSpace(personaID),
			"status":     bson.M{"$ne": entity.StatusDeleted},
		},
		bson.M{"$set": patch},
		options.FindOneAndUpdate().SetReturnDocument(options.After),
	).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.Persona).ResNotFound("找不到拷貝任務")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) Delete(ctx context.Context, tenantID, ownerUID, personaID, missionID string) error {
	_, err := r.Update(ctx, tenantID, ownerUID, personaID, missionID, map[string]interface{}{
		"status": entity.StatusDeleted,
	})
	return err
}

func (r *mongoRepository) findOne(ctx context.Context, filter bson.M) (*entity.Mission, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	var out entity.Mission
	err := r.collection.FindOne(ctx, filter).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.Persona).ResNotFound("找不到拷貝任務")
		}
		return nil, err
	}
	return &out, nil
}