package repository

import (
	"context"
	"errors"
	"fmt"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"

	"osdb/internal/domain"
	"osdb/internal/handler"
)

type PublicationRepo struct {
	pool *pgxpool.Pool
}

func NewPublicationRepo(pool *pgxpool.Pool) *PublicationRepo {
	return &PublicationRepo{pool: pool}
}

func pubImageURL(pubID int) string {
	return fmt.Sprintf("/api/v1/publications/%d/image", pubID)
}

func descURL(pubID, descID int) string {
	return fmt.Sprintf("/api/v1/publications/%d/descriptions/%d", pubID, descID)
}

func pubFruitImgURL(pubID, imgID int) string {
	return fmt.Sprintf("/api/v1/publications/%d/fruit-images/%d", pubID, imgID)
}

func mapPubPgError(err error) error {
	return mapPgError(err)
}

func mapPgErrorToPub(err error) error {
	e := mapPgError(err)
	if errors.Is(e, handler.ErrDuplicateOSDBNumber) {
		return handler.ErrDuplicateOSDBPubID
	}
	return e
}

func mapPgErrorToDesc(err error) error {
	e := mapPgError(err)
	if errors.Is(e, handler.ErrDuplicateOSDBNumber) {
		return handler.ErrDuplicatePubDescription
	}
	return e
}

func (r *PublicationRepo) List(ctx context.Context) ([]domain.Publication, error) {
	rows, err := r.pool.Query(ctx,
		`SELECT id, title, author, osdb_pub_id,
		        CASE WHEN image_data IS NOT NULL THEN true ELSE false END AS has_image,
		        created_at, updated_at
		 FROM publications ORDER BY id`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	pubs := []domain.Publication{}
	for rows.Next() {
		var p domain.Publication
		var hasImage bool
		if err := rows.Scan(&p.ID, &p.Title, &p.Author, &p.OSDBPubID, &hasImage, &p.CreatedAt, &p.UpdatedAt); err != nil {
			return nil, err
		}
		if hasImage {
			url := pubImageURL(p.ID)
			p.ImageURL = &url
		}
		pubs = append(pubs, p)
	}
	return pubs, rows.Err()
}

func (r *PublicationRepo) Get(ctx context.Context, id int) (domain.Publication, error) {
	var p domain.Publication
	var hasImage bool
	err := r.pool.QueryRow(ctx,
		`SELECT id, title, author, osdb_pub_id,
		        CASE WHEN image_data IS NOT NULL THEN true ELSE false END,
		        created_at, updated_at
		 FROM publications WHERE id=$1`, id).
		Scan(&p.ID, &p.Title, &p.Author, &p.OSDBPubID, &hasImage, &p.CreatedAt, &p.UpdatedAt)
	if errors.Is(err, pgx.ErrNoRows) {
		return domain.Publication{}, handler.ErrNotFound
	}
	if err != nil {
		return domain.Publication{}, err
	}
	if hasImage {
		url := pubImageURL(p.ID)
		p.ImageURL = &url
	}
	return p, nil
}

func (r *PublicationRepo) Create(ctx context.Context, dto domain.PublicationWriteDTO) (domain.Publication, error) {
	var p domain.Publication
	err := r.pool.QueryRow(ctx,
		`INSERT INTO publications (title, author, osdb_pub_id)
		 VALUES ($1, $2, $3)
		 RETURNING id, title, author, osdb_pub_id, created_at, updated_at`,
		dto.Title, dto.Author, dto.OSDBPubID).
		Scan(&p.ID, &p.Title, &p.Author, &p.OSDBPubID, &p.CreatedAt, &p.UpdatedAt)
	if err != nil {
		return domain.Publication{}, mapPgErrorToPub(err)
	}
	return p, nil
}

func (r *PublicationRepo) Update(ctx context.Context, id int, dto domain.PublicationWriteDTO) (domain.Publication, error) {
	var p domain.Publication
	var hasImage bool
	err := r.pool.QueryRow(ctx,
		`UPDATE publications SET title=$1, author=$2, osdb_pub_id=$3, updated_at=NOW()
		 WHERE id=$4
		 RETURNING id, title, author, osdb_pub_id,
		           CASE WHEN image_data IS NOT NULL THEN true ELSE false END,
		           created_at, updated_at`,
		dto.Title, dto.Author, dto.OSDBPubID, id).
		Scan(&p.ID, &p.Title, &p.Author, &p.OSDBPubID, &hasImage, &p.CreatedAt, &p.UpdatedAt)
	if errors.Is(err, pgx.ErrNoRows) {
		return domain.Publication{}, handler.ErrNotFound
	}
	if err != nil {
		return domain.Publication{}, mapPgErrorToPub(err)
	}
	if hasImage {
		url := pubImageURL(p.ID)
		p.ImageURL = &url
	}
	return p, nil
}

func (r *PublicationRepo) Delete(ctx context.Context, id int) error {
	tag, err := r.pool.Exec(ctx, `DELETE FROM publications WHERE id=$1`, id)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return handler.ErrNotFound
	}
	return nil
}

func (r *PublicationRepo) SetImage(ctx context.Context, pubID int, data []byte) error {
	tag, err := r.pool.Exec(ctx,
		`UPDATE publications SET image_data=$1, updated_at=NOW() WHERE id=$2`, data, pubID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return handler.ErrNotFound
	}
	return nil
}

func (r *PublicationRepo) GetImageData(ctx context.Context, pubID int) ([]byte, error) {
	var data []byte
	err := r.pool.QueryRow(ctx,
		`SELECT image_data FROM publications WHERE id=$1`, pubID).Scan(&data)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, handler.ErrNotFound
	}
	if err != nil {
		return nil, err
	}
	if data == nil {
		return nil, handler.ErrNotFound
	}
	return data, nil
}

func (r *PublicationRepo) DeleteImage(ctx context.Context, pubID int) error {
	var data []byte
	err := r.pool.QueryRow(ctx,
		`UPDATE publications SET image_data=NULL, updated_at=NOW() WHERE id=$1 RETURNING image_data`, pubID).
		Scan(&data)
	if errors.Is(err, pgx.ErrNoRows) {
		return handler.ErrNotFound
	}
	return err
}

func (r *PublicationRepo) ListFruits(ctx context.Context, pubID int) ([]domain.PublicationFruit, error) {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return nil, err
	}
	rows, err := r.pool.Query(ctx,
		`SELECT f.id, f.name, f.osdb_number
		 FROM fruits f
		 JOIN publication_fruits pf ON pf.fruit_id = f.id
		 WHERE pf.publication_id=$1 ORDER BY f.name`, pubID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	fruits := []domain.PublicationFruit{}
	for rows.Next() {
		var pf domain.PublicationFruit
		if err := rows.Scan(&pf.FruitID, &pf.Name, &pf.OSDBNumber); err != nil {
			return nil, err
		}
		fruits = append(fruits, pf)
	}
	return fruits, rows.Err()
}

func (r *PublicationRepo) LinkFruit(ctx context.Context, pubID, fruitID int) error {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return err
	}
	_, err := r.pool.Exec(ctx,
		`INSERT INTO publication_fruits (publication_id, fruit_id) VALUES ($1, $2)
		 ON CONFLICT DO NOTHING`, pubID, fruitID)
	return err
}

func (r *PublicationRepo) UnlinkFruit(ctx context.Context, pubID, fruitID int) error {
	tag, err := r.pool.Exec(ctx,
		`DELETE FROM publication_fruits WHERE publication_id=$1 AND fruit_id=$2`, pubID, fruitID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return handler.ErrNotFound
	}
	return nil
}

func (r *PublicationRepo) ListDescriptions(ctx context.Context, pubID int) ([]domain.PublicationDescription, error) {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return nil, err
	}
	rows, err := r.pool.Query(ctx,
		`SELECT pd.id, pd.publication_id, pd.fruit_id, f.name, p.title, pd.created_at
		 FROM publication_descriptions pd
		 JOIN fruits f ON f.id = pd.fruit_id
		 JOIN publications p ON p.id = pd.publication_id
		 WHERE pd.publication_id=$1 ORDER BY pd.id`, pubID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	descs := []domain.PublicationDescription{}
	for rows.Next() {
		var d domain.PublicationDescription
		if err := rows.Scan(&d.ID, &d.PublicationID, &d.FruitID, &d.FruitName, &d.PublicationTitle, &d.CreatedAt); err != nil {
			return nil, err
		}
		d.URL = descURL(d.PublicationID, d.ID)
		descs = append(descs, d)
	}
	return descs, rows.Err()
}

func (r *PublicationRepo) AddDescription(ctx context.Context, pubID, fruitID int, data []byte) (domain.PublicationDescription, error) {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return domain.PublicationDescription{}, err
	}
	var d domain.PublicationDescription
	err := r.pool.QueryRow(ctx,
		`INSERT INTO publication_descriptions (publication_id, fruit_id, pdf_data)
		 VALUES ($1, $2, $3)
		 RETURNING id, publication_id, fruit_id, created_at`,
		pubID, fruitID, data).
		Scan(&d.ID, &d.PublicationID, &d.FruitID, &d.CreatedAt)
	if err != nil {
		return domain.PublicationDescription{}, mapPgErrorToDesc(err)
	}
	d.URL = descURL(d.PublicationID, d.ID)
	return d, nil
}

func (r *PublicationRepo) GetDescriptionData(ctx context.Context, pubID, descID int) ([]byte, error) {
	var data []byte
	err := r.pool.QueryRow(ctx,
		`SELECT pdf_data FROM publication_descriptions WHERE id=$1 AND publication_id=$2`,
		descID, pubID).Scan(&data)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, handler.ErrNotFound
	}
	return data, err
}

func (r *PublicationRepo) DeleteDescription(ctx context.Context, pubID, descID int) error {
	tag, err := r.pool.Exec(ctx,
		`DELETE FROM publication_descriptions WHERE id=$1 AND publication_id=$2`, descID, pubID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return handler.ErrNotFound
	}
	return nil
}

func (r *PublicationRepo) ListFruitImages(ctx context.Context, pubID int) ([]domain.PublicationFruitImage, error) {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return nil, err
	}
	rows, err := r.pool.Query(ctx,
		`SELECT pfi.id, pfi.publication_id, p.title, p.author, pfi.fruit_id, pfi.filename, pfi.image_type, pfi.created_at
		 FROM publication_fruit_images pfi
		 JOIN publications p ON p.id = pfi.publication_id
		 WHERE pfi.publication_id=$1 ORDER BY pfi.id`, pubID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	imgs := []domain.PublicationFruitImage{}
	for rows.Next() {
		var img domain.PublicationFruitImage
		if err := rows.Scan(&img.ID, &img.PublicationID, &img.PublicationTitle, &img.PublicationAuthor,
			&img.FruitID, &img.Filename, &img.ImageType, &img.CreatedAt); err != nil {
			return nil, err
		}
		img.URL = pubFruitImgURL(img.PublicationID, img.ID)
		imgs = append(imgs, img)
	}
	return imgs, rows.Err()
}

func (r *PublicationRepo) AddFruitImage(ctx context.Context, pubID, fruitID int, filename *string, data []byte) (domain.PublicationFruitImage, error) {
	if err := r.requirePublication(ctx, pubID); err != nil {
		return domain.PublicationFruitImage{}, err
	}
	var img domain.PublicationFruitImage
	err := r.pool.QueryRow(ctx,
		`INSERT INTO publication_fruit_images (publication_id, fruit_id, filename, data, image_type)
		 VALUES ($1, $2, $3, $4, 'fruit')
		 RETURNING id, publication_id, fruit_id, filename, image_type, created_at`,
		pubID, fruitID, filename, data).
		Scan(&img.ID, &img.PublicationID, &img.FruitID, &img.Filename, &img.ImageType, &img.CreatedAt)
	if err != nil {
		return domain.PublicationFruitImage{}, err
	}
	img.URL = pubFruitImgURL(img.PublicationID, img.ID)
	return img, nil
}

func (r *PublicationRepo) GetFruitImageData(ctx context.Context, pubID, imgID int) ([]byte, error) {
	var data []byte
	err := r.pool.QueryRow(ctx,
		`SELECT data FROM publication_fruit_images WHERE id=$1 AND publication_id=$2`,
		imgID, pubID).Scan(&data)
	if errors.Is(err, pgx.ErrNoRows) {
		return nil, handler.ErrNotFound
	}
	return data, err
}

func (r *PublicationRepo) DeleteFruitImage(ctx context.Context, pubID, imgID int) error {
	tag, err := r.pool.Exec(ctx,
		`DELETE FROM publication_fruit_images WHERE id=$1 AND publication_id=$2`, imgID, pubID)
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return handler.ErrNotFound
	}
	return nil
}

func (r *PublicationRepo) GetFruitDescriptions(ctx context.Context, fruitID int) ([]domain.PublicationDescription, error) {
	rows, err := r.pool.Query(ctx,
		`SELECT pd.id, pd.publication_id, pd.fruit_id, f.name, p.title, pd.created_at
		 FROM publication_descriptions pd
		 JOIN fruits f ON f.id = pd.fruit_id
		 JOIN publications p ON p.id = pd.publication_id
		 WHERE pd.fruit_id=$1 ORDER BY pd.id`, fruitID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	descs := []domain.PublicationDescription{}
	for rows.Next() {
		var d domain.PublicationDescription
		if err := rows.Scan(&d.ID, &d.PublicationID, &d.FruitID, &d.FruitName, &d.PublicationTitle, &d.CreatedAt); err != nil {
			return nil, err
		}
		d.URL = descURL(d.PublicationID, d.ID)
		descs = append(descs, d)
	}
	return descs, rows.Err()
}

func (r *PublicationRepo) GetFruitPublicationImages(ctx context.Context, fruitID int) ([]domain.PublicationFruitImage, error) {
	rows, err := r.pool.Query(ctx,
		`SELECT pfi.id, pfi.publication_id, p.title, p.author, pfi.fruit_id, pfi.filename, pfi.image_type, pfi.created_at
		 FROM publication_fruit_images pfi
		 JOIN publications p ON p.id = pfi.publication_id
		 WHERE pfi.fruit_id=$1 ORDER BY pfi.id`, fruitID)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	imgs := []domain.PublicationFruitImage{}
	for rows.Next() {
		var img domain.PublicationFruitImage
		if err := rows.Scan(&img.ID, &img.PublicationID, &img.PublicationTitle, &img.PublicationAuthor,
			&img.FruitID, &img.Filename, &img.ImageType, &img.CreatedAt); err != nil {
			return nil, err
		}
		img.URL = pubFruitImgURL(img.PublicationID, img.ID)
		imgs = append(imgs, img)
	}
	return imgs, rows.Err()
}

func (r *PublicationRepo) requirePublication(ctx context.Context, pubID int) error {
	var exists bool
	err := r.pool.QueryRow(ctx, `SELECT EXISTS(SELECT 1 FROM publications WHERE id=$1)`, pubID).Scan(&exists)
	if err != nil {
		return err
	}
	if !exists {
		return handler.ErrNotFound
	}
	return nil
}