package repository

import (
	"context"
	"strings"

	app "haixun-backend/internal/library/errors"
	"haixun-backend/internal/library/errors/code"
	"haixun-backend/internal/model/content_formula/domain/entity"
	domrepo "haixun-backend/internal/model/content_formula/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: "account_id", Value: 1},
				{Key: "update_at", Value: -1},
			},
		},
	})
	return err
}

func actorFilter(tenantID, ownerUID, accountID string) bson.M {
	return bson.M{
		"tenant_id":  strings.TrimSpace(tenantID),
		"owner_uid":  strings.TrimSpace(ownerUID),
		"account_id": strings.TrimSpace(accountID),
	}
}

func normalizePage(page, pageSize int) (int, int) {
	if page <= 0 {
		page = 1
	}
	if pageSize <= 0 {
		pageSize = 20
	}
	if pageSize > 100 {
		pageSize = 100
	}
	return page, pageSize
}

func (r *mongoRepository) Create(ctx context.Context, formula *entity.ContentFormula) error {
	if r.collection == nil {
		return app.For(code.ThreadsAccount).DBUnavailable("Mongo is not configured")
	}
	if formula == nil {
		return app.For(code.ThreadsAccount).InputMissingRequired("formula is required")
	}
	_, err := r.collection.InsertOne(ctx, formula)
	return err
}

func (r *mongoRepository) Get(ctx context.Context, tenantID, ownerUID, accountID, formulaID string) (*entity.ContentFormula, error) {
	if r.collection == nil {
		return nil, app.For(code.ThreadsAccount).DBUnavailable("Mongo is not configured")
	}
	formulaID = strings.TrimSpace(formulaID)
	if formulaID == "" {
		return nil, app.For(code.ThreadsAccount).InputMissingRequired("formula_id is required")
	}
	filter := actorFilter(tenantID, ownerUID, accountID)
	filter["_id"] = formulaID
	var out entity.ContentFormula
	err := r.collection.FindOne(ctx, filter).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.ThreadsAccount).ResNotFound("content formula not found")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) Update(ctx context.Context, tenantID, ownerUID, accountID, formulaID string, patch map[string]interface{}) (*entity.ContentFormula, error) {
	if r.collection == nil {
		return nil, app.For(code.ThreadsAccount).DBUnavailable("Mongo is not configured")
	}
	if len(patch) == 0 {
		return nil, app.For(code.ThreadsAccount).InputMissingRequired("patch is required")
	}
	filter := actorFilter(tenantID, ownerUID, accountID)
	filter["_id"] = strings.TrimSpace(formulaID)
	opts := options.FindOneAndUpdate().SetReturnDocument(options.After)
	var out entity.ContentFormula
	err := r.collection.FindOneAndUpdate(ctx, filter, bson.M{"$set": patch}, opts).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.ThreadsAccount).ResNotFound("content formula not found")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) Delete(ctx context.Context, tenantID, ownerUID, accountID, formulaID string) error {
	if r.collection == nil {
		return app.For(code.ThreadsAccount).DBUnavailable("Mongo is not configured")
	}
	filter := actorFilter(tenantID, ownerUID, accountID)
	filter["_id"] = strings.TrimSpace(formulaID)
	res, err := r.collection.DeleteOne(ctx, filter)
	if err != nil {
		return err
	}
	if res.DeletedCount == 0 {
		return app.For(code.ThreadsAccount).ResNotFound("content formula not found")
	}
	return nil
}

func (r *mongoRepository) List(ctx context.Context, filter domrepo.ListFilter) (*domrepo.ListResult, error) {
	if r.collection == nil {
		return nil, app.For(code.ThreadsAccount).DBUnavailable("Mongo is not configured")
	}
	page, pageSize := normalizePage(filter.Page, filter.PageSize)
	mongoFilter := actorFilter(filter.TenantID, filter.OwnerUID, filter.AccountID)
	if sourceType := strings.TrimSpace(filter.SourceType); sourceType != "" {
		mongoFilter["source_type"] = sourceType
	}
	if tag := strings.TrimSpace(filter.Tag); tag != "" {
		mongoFilter["tags"] = tag
	}
	total, err := r.collection.CountDocuments(ctx, mongoFilter)
	if err != nil {
		return nil, err
	}
	opts := options.Find().
		SetSort(bson.D{{Key: "update_at", Value: -1}}).
		SetSkip(int64((page - 1) * pageSize)).
		SetLimit(int64(pageSize))
	cur, err := r.collection.Find(ctx, mongoFilter, opts)
	if err != nil {
		return nil, err
	}
	defer cur.Close(ctx)
	var items []entity.ContentFormula
	if err := cur.All(ctx, &items); err != nil {
		return nil, err
	}
	return &domrepo.ListResult{Items: items, Total: total}, nil
}