package repository

import (
	"context"

	"go.mongodb.org/mongo-driver/v2/bson"
	"go.mongodb.org/mongo-driver/v2/mongo"
	"go.mongodb.org/mongo-driver/v2/mongo/options"
)

type EssayRepo struct {
	col *mongo.Collection
}

func NewEssayRepo(db *MongoDB) *EssayRepo {
	return &EssayRepo{col: db.Collection("essays")}
}

type EssayDoc struct {
	ID         bson.ObjectID `bson:"_id" json:"id"`
	Slug       string        `bson:"slug" json:"slug"`
	Title      string        `bson:"title" json:"title"`
	Author     string        `bson:"author" json:"author"`
	Year       *int          `bson:"year,omitempty" json:"year,omitempty"`
	Group      *string       `bson:"group,omitempty" json:"group,omitempty"`
	Order      int           `bson:"order" json:"order"`
	Paragraphs []string      `bson:"paragraphs" json:"paragraphs"`
}

type EssaySummaryDoc struct {
	ID    bson.ObjectID `bson:"_id" json:"id"`
	Slug  string        `bson:"slug" json:"slug"`
	Title string        `bson:"title" json:"title"`
	Year  *int          `bson:"year,omitempty" json:"year,omitempty"`
	Group *string       `bson:"group,omitempty" json:"group,omitempty"`
}

func (r *EssayRepo) GetAll(ctx context.Context) ([]EssaySummaryDoc, error) {
	opts := options.Find().
		SetSort(bson.M{"group": 1, "order": 1}).
		SetProjection(bson.M{"slug": 1, "title": 1, "year": 1, "group": 1})
	cursor, err := r.col.Find(ctx, bson.M{}, opts)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)
	var results []EssaySummaryDoc
	if err := cursor.All(ctx, &results); err != nil {
		return nil, err
	}
	return results, nil
}

func (r *EssayRepo) GetBySlug(ctx context.Context, slug string) (*EssayDoc, error) {
	var doc EssayDoc
	err := r.col.FindOne(ctx, bson.M{"slug": slug}).Decode(&doc)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, nil
		}
		return nil, err
	}
	return &doc, nil
}