package repository

import (
	"context"
	"strings"

	app "haixun-backend/internal/library/errors"
	"haixun-backend/internal/library/errors/code"
	"haixun-backend/internal/model/copy_draft/domain/entity"
	domrepo "haixun-backend/internal/model/copy_draft/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: "create_at", Value: -1},
			},
		},
		{
			Keys: bson.D{
				{Key: "tenant_id", Value: 1},
				{Key: "owner_uid", Value: 1},
				{Key: "persona_id", Value: 1},
				{Key: "copy_mission_id", Value: 1},
				{Key: "sort_order", Value: 1},
			},
		},
	})
	return err
}

func personaFilter(tenantID, ownerUID, personaID string) bson.M {
	return bson.M{
		"tenant_id":  strings.TrimSpace(tenantID),
		"owner_uid":  strings.TrimSpace(ownerUID),
		"persona_id": strings.TrimSpace(personaID),
	}
}

func (r *mongoRepository) CreateMany(ctx context.Context, drafts []*entity.CopyDraft) error {
	if r.collection == nil {
		return app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	if len(drafts) == 0 {
		return nil
	}
	docs := make([]any, 0, len(drafts))
	for _, draft := range drafts {
		if draft == nil {
			continue
		}
		docs = append(docs, draft)
	}
	if len(docs) == 0 {
		return nil
	}
	_, err := r.collection.InsertMany(ctx, docs)
	return err
}

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

func (r *mongoRepository) List(ctx context.Context, tenantID, ownerUID, personaID string, limit int) ([]entity.CopyDraft, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	if limit <= 0 {
		limit = 50
	}
	if limit > 200 {
		limit = 200
	}
	opts := options.Find().
		SetSort(bson.D{{Key: "sort_order", Value: 1}, {Key: "create_at", Value: -1}}).
		SetLimit(int64(limit))
	cur, err := r.collection.Find(ctx, personaFilter(tenantID, ownerUID, personaID), opts)
	if err != nil {
		return nil, err
	}
	defer cur.Close(ctx)
	var out []entity.CopyDraft
	if err := cur.All(ctx, &out); err != nil {
		return nil, err
	}
	return out, nil
}

func (r *mongoRepository) Get(ctx context.Context, tenantID, ownerUID, personaID, draftID string) (*entity.CopyDraft, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	draftID = strings.TrimSpace(draftID)
	if draftID == "" {
		return nil, app.For(code.Persona).InputMissingRequired("draft_id is required")
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["_id"] = draftID
	var out entity.CopyDraft
	err := r.collection.FindOne(ctx, filter).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.Persona).ResNotFound("copy draft not found")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) Update(ctx context.Context, tenantID, ownerUID, personaID, draftID string, patch map[string]interface{}) (*entity.CopyDraft, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	if len(patch) == 0 {
		return nil, app.For(code.Persona).InputMissingRequired("patch is required")
	}
	draftID = strings.TrimSpace(draftID)
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["_id"] = draftID
	opts := options.FindOneAndUpdate().SetReturnDocument(options.After)
	var out entity.CopyDraft
	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.Persona).ResNotFound("copy draft not found")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) DeleteByMission(ctx context.Context, tenantID, ownerUID, personaID, missionID string) error {
	if r.collection == nil {
		return app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	missionID = strings.TrimSpace(missionID)
	if missionID == "" {
		return app.For(code.Persona).InputMissingRequired("copy_mission_id is required")
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["copy_mission_id"] = missionID
	_, err := r.collection.DeleteMany(ctx, filter)
	return err
}

func (r *mongoRepository) DeleteByMissionAndType(ctx context.Context, tenantID, ownerUID, personaID, missionID, draftType string) error {
	if r.collection == nil {
		return app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	missionID = strings.TrimSpace(missionID)
	draftType = strings.TrimSpace(draftType)
	if missionID == "" || draftType == "" {
		return app.For(code.Persona).InputMissingRequired("copy_mission_id and draft_type are required")
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["copy_mission_id"] = missionID
	filter["draft_type"] = draftType
	_, err := r.collection.DeleteMany(ctx, filter)
	return err
}

func (r *mongoRepository) ListByMission(ctx context.Context, tenantID, ownerUID, personaID, missionID string, limit int) ([]entity.CopyDraft, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	missionID = strings.TrimSpace(missionID)
	if missionID == "" {
		return nil, app.For(code.Persona).InputMissingRequired("copy_mission_id is required")
	}
	if limit <= 0 {
		limit = 50
	}
	if limit > 200 {
		limit = 200
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["copy_mission_id"] = missionID
	opts := options.Find().
		SetSort(bson.D{{Key: "sort_order", Value: 1}, {Key: "create_at", Value: -1}}).
		SetLimit(int64(limit))
	cur, err := r.collection.Find(ctx, filter, opts)
	if err != nil {
		return nil, err
	}
	defer cur.Close(ctx)
	var out []entity.CopyDraft
	if err := cur.All(ctx, &out); err != nil {
		return nil, err
	}
	return out, nil
}