package store

import (
	"database/sql"
	"encoding/json"
	"errors"
	"strings"
	"time"

	_ "github.com/jackc/pgx/v5/stdlib"
)

type PostgresStore struct {
	db *sql.DB
}

func NewPostgresStore(databaseURL string) (*PostgresStore, error) {
	db, err := sql.Open("pgx", databaseURL)
	if err != nil {
		return nil, err
	}
	if err := db.Ping(); err != nil {
		return nil, err
	}
	return &PostgresStore{db: db}, nil
}

func (s *PostgresStore) Close() error {
	return s.db.Close()
}

func (s *PostgresStore) UpsertUser(user User) {
	_, _ = s.db.Exec(
		`INSERT INTO users (public_key, inviter, created_at) VALUES ($1, $2, $3)
		 ON CONFLICT (public_key) DO UPDATE SET inviter = EXCLUDED.inviter`,
		user.PublicKey, nullStr(user.Inviter), user.CreatedAt,
	)
}

func (s *PostgresStore) GetUser(publicKey string) (User, error) {
	var u User
	err := s.db.QueryRow(
		`SELECT public_key, COALESCE(inviter,''), created_at FROM users WHERE public_key = $1`,
		publicKey,
	).Scan(&u.PublicKey, &u.Inviter, &u.CreatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return User{}, ErrNotFound
	}
	if err != nil {
		return User{}, err
	}
	return u, nil
}

func (s *PostgresStore) CreateChallenge(ch Challenge) error {
	_, err := s.db.Exec(
		`INSERT INTO challenges (nonce, public_key, ip, expires_at, used) VALUES ($1, $2, $3, $4, $5)`,
		ch.Nonce, ch.PublicKey, nullStr(ch.IP), ch.ExpiresAt, ch.Used,
	)
	if err != nil {
		if isUniqueViolation(err) {
			return ErrAlreadyExists
		}
		return err
	}
	return nil
}

func (s *PostgresStore) GetChallenge(nonce string) (Challenge, error) {
	var ch Challenge
	err := s.db.QueryRow(
		`SELECT nonce, public_key, COALESCE(ip,''), expires_at, used FROM challenges WHERE nonce = $1`,
		nonce,
	).Scan(&ch.Nonce, &ch.PublicKey, &ch.IP, &ch.ExpiresAt, &ch.Used)
	if errors.Is(err, sql.ErrNoRows) {
		return Challenge{}, ErrNotFound
	}
	if err != nil {
		return Challenge{}, err
	}
	return ch, nil
}

func (s *PostgresStore) MarkChallengeUsed(nonce string) error {
	res, err := s.db.Exec(`UPDATE challenges SET used = true WHERE nonce = $1`, nonce)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) SaveSession(session Session) {
	_, _ = s.db.Exec(
		`INSERT INTO sessions (token, public_key, expires_at) VALUES ($1, $2, $3)
		 ON CONFLICT (token) DO UPDATE SET public_key = EXCLUDED.public_key, expires_at = EXCLUDED.expires_at`,
		session.Token, session.PublicKey, session.ExpiresAt,
	)
}

func (s *PostgresStore) GetSession(token string) (Session, error) {
	var sess Session
	err := s.db.QueryRow(
		`SELECT token, public_key, expires_at FROM sessions WHERE token = $1`,
		token,
	).Scan(&sess.Token, &sess.PublicKey, &sess.ExpiresAt)
	if errors.Is(err, sql.ErrNoRows) {
		return Session{}, ErrNotFound
	}
	if err != nil {
		return Session{}, err
	}
	return sess, nil
}

func (s *PostgresStore) SaveInvitation(inv Invitation) error {
	_, err := s.db.Exec(
		`INSERT INTO invitations (jti, inviter_public_key, invitee_public_key, expires_at, max_uses, used_count)
		 VALUES ($1, $2, $3, $4, $5, $6)`,
		inv.JTI, inv.InviterPublicKey, nullStr(inv.InviteePublicKey), inv.ExpiresAt, inv.MaxUses, inv.UsedCount,
	)
	if err != nil {
		if isUniqueViolation(err) {
			return ErrAlreadyExists
		}
		return err
	}
	return nil
}

func (s *PostgresStore) GetInvitation(jti string) (Invitation, error) {
	var inv Invitation
	var invitee sql.NullString
	err := s.db.QueryRow(
		`SELECT jti, inviter_public_key, invitee_public_key, expires_at, max_uses, used_count
		 FROM invitations WHERE jti = $1`,
		jti,
	).Scan(&inv.JTI, &inv.InviterPublicKey, &invitee, &inv.ExpiresAt, &inv.MaxUses, &inv.UsedCount)
	if errors.Is(err, sql.ErrNoRows) {
		return Invitation{}, ErrNotFound
	}
	if err != nil {
		return Invitation{}, err
	}
	inv.InviteePublicKey = invitee.String
	return inv, nil
}

func (s *PostgresStore) IncrementInvitationUsage(jti string) error {
	res, err := s.db.Exec(`UPDATE invitations SET used_count = used_count + 1 WHERE jti = $1`, jti)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) SaveCollection(c Collection) {
	_, _ = s.db.Exec(
		`INSERT INTO collections (id, owner_key, name, created_at) VALUES ($1, $2, $3, $4)
		 ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name`,
		c.ID, c.OwnerKey, c.Name, c.CreatedAt,
	)
}

func (s *PostgresStore) ListCollectionsByOwner(owner string) []Collection {
	rows, err := s.db.Query(
		`SELECT id, owner_key, name, created_at FROM collections WHERE owner_key = $1 ORDER BY created_at`,
		owner,
	)
	if err != nil {
		return nil
	}
	defer rows.Close()
	var result []Collection
	for rows.Next() {
		var c Collection
		if err := rows.Scan(&c.ID, &c.OwnerKey, &c.Name, &c.CreatedAt); err != nil {
			return result
		}
		result = append(result, c)
	}
	return result
}

func (s *PostgresStore) GetCollection(id string) (Collection, error) {
	var c Collection
	err := s.db.QueryRow(
		`SELECT id, owner_key, name, created_at FROM collections WHERE id = $1`,
		id,
	).Scan(&c.ID, &c.OwnerKey, &c.Name, &c.CreatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return Collection{}, ErrNotFound
	}
	if err != nil {
		return Collection{}, err
	}
	return c, nil
}

func (s *PostgresStore) DeleteCollection(id string) error {
	res, err := s.db.Exec(`DELETE FROM collections WHERE id = $1`, id)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) SaveFeature(f Feature) {
	geom, _ := json.Marshal(f.Geometry)
	props, _ := json.Marshal(f.Properties)
	z := 0.0
	if len(f.Geometry.Coordinates) >= 3 {
		z = f.Geometry.Coordinates[2]
	}
	_, _ = s.db.Exec(
		`INSERT INTO features (id, collection_id, owner_key, type, geometry, properties, created_at, updated_at, geom)
		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, ST_SetSRID(ST_MakePoint($9, $10, $11), 4326))
		 ON CONFLICT (id) DO UPDATE
		 SET geometry = EXCLUDED.geometry,
		     properties = EXCLUDED.properties,
		     updated_at = EXCLUDED.updated_at,
		     geom = EXCLUDED.geom`,
		f.ID, f.CollectionID, f.OwnerKey, f.Type, geom, props, f.CreatedAt, f.UpdatedAt,
		f.Geometry.Coordinates[0], f.Geometry.Coordinates[1], z,
	)
}

func (s *PostgresStore) ListFeaturesByCollection(collectionID string) []Feature {
	rows, err := s.db.Query(
		`SELECT id, collection_id, owner_key, type, geometry, properties, created_at, updated_at
		 FROM features WHERE collection_id = $1 ORDER BY created_at`,
		collectionID,
	)
	if err != nil {
		return nil
	}
	defer rows.Close()
	var result []Feature
	for rows.Next() {
		var f Feature
		var geom, props []byte
		if err := rows.Scan(&f.ID, &f.CollectionID, &f.OwnerKey, &f.Type, &geom, &props, &f.CreatedAt, &f.UpdatedAt); err != nil {
			return result
		}
		_ = json.Unmarshal(geom, &f.Geometry)
		_ = json.Unmarshal(props, &f.Properties)
		result = append(result, f)
	}
	return result
}

func (s *PostgresStore) GetFeature(featureID string) (Feature, error) {
	var f Feature
	var geom, props []byte
	err := s.db.QueryRow(
		`SELECT id, collection_id, owner_key, type, geometry, properties, created_at, updated_at
		 FROM features WHERE id = $1`,
		featureID,
	).Scan(&f.ID, &f.CollectionID, &f.OwnerKey, &f.Type, &geom, &props, &f.CreatedAt, &f.UpdatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return Feature{}, ErrNotFound
	}
	if err != nil {
		return Feature{}, err
	}
	_ = json.Unmarshal(geom, &f.Geometry)
	_ = json.Unmarshal(props, &f.Properties)
	return f, nil
}

func (s *PostgresStore) DeleteFeature(featureID string) error {
	res, err := s.db.Exec(`DELETE FROM features WHERE id = $1`, featureID)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) SaveUserLogin(ul UserLogin) {
	_, _ = s.db.Exec(
		`INSERT INTO user_logins (public_key, ip, created_at) VALUES ($1, $2, $3)`,
		ul.PublicKey, nullStr(ul.IP), ul.CreatedAt,
	)
}

func (s *PostgresStore) SaveAsset(a Asset) {
	_, _ = s.db.Exec(
		`INSERT INTO assets (id, owner_key, checksum, ext, kind, mime_type, size_bytes, object_key, is_public, created_at, updated_at)
		 VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
		 ON CONFLICT (id) DO UPDATE
		 SET kind = EXCLUDED.kind,
		     mime_type = EXCLUDED.mime_type,
		     size_bytes = EXCLUDED.size_bytes,
		     is_public = EXCLUDED.is_public,
		     updated_at = EXCLUDED.updated_at`,
		a.ID, a.OwnerKey, a.Checksum, a.Ext, a.Kind, nullStr(a.MimeType), a.SizeBytes, a.ObjectKey, a.IsPublic, a.CreatedAt, a.UpdatedAt,
	)
}

func (s *PostgresStore) GetAsset(assetID string) (Asset, error) {
	var a Asset
	var mimeType sql.NullString
	err := s.db.QueryRow(
		`SELECT id, owner_key, checksum, ext, kind, mime_type, size_bytes, object_key, is_public, created_at, updated_at
		 FROM assets WHERE id = $1`,
		assetID,
	).Scan(&a.ID, &a.OwnerKey, &a.Checksum, &a.Ext, &a.Kind, &mimeType, &a.SizeBytes, &a.ObjectKey, &a.IsPublic, &a.CreatedAt, &a.UpdatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return Asset{}, ErrNotFound
	}
	if err != nil {
		return Asset{}, err
	}
	a.MimeType = mimeType.String
	return a, nil
}

func (s *PostgresStore) GetAssetByOwnerChecksumExt(ownerKey, checksum, ext string) (Asset, error) {
	var a Asset
	var mimeType sql.NullString
	err := s.db.QueryRow(
		`SELECT id, owner_key, checksum, ext, kind, mime_type, size_bytes, object_key, is_public, created_at, updated_at
		 FROM assets WHERE owner_key = $1 AND checksum = $2 AND ext = $3`,
		ownerKey, checksum, ext,
	).Scan(&a.ID, &a.OwnerKey, &a.Checksum, &a.Ext, &a.Kind, &mimeType, &a.SizeBytes, &a.ObjectKey, &a.IsPublic, &a.CreatedAt, &a.UpdatedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return Asset{}, ErrNotFound
	}
	if err != nil {
		return Asset{}, err
	}
	a.MimeType = mimeType.String
	return a, nil
}

func (s *PostgresStore) SetAssetPublic(assetID string, isPublic bool) error {
	res, err := s.db.Exec(`UPDATE assets SET is_public = $2, updated_at = NOW() WHERE id = $1`, assetID, isPublic)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) LinkAssetToFeature(featureID, assetID, name, description string) error {
	_, err := s.db.Exec(
		`INSERT INTO feature_asset_links (feature_id, asset_id, name, description)
		 VALUES ($1, $2, $3, $4)
		 ON CONFLICT (feature_id, asset_id) DO UPDATE SET name = EXCLUDED.name, description = EXCLUDED.description`,
		featureID, assetID, nullStr(name), nullStr(description),
	)
	return err
}

func (s *PostgresStore) UnlinkAssetFromFeature(featureID, assetID string) error {
	res, err := s.db.Exec(`DELETE FROM feature_asset_links WHERE feature_id = $1 AND asset_id = $2`, featureID, assetID)
	if err != nil {
		return err
	}
	n, _ := res.RowsAffected()
	if n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *PostgresStore) ListAssetsByFeature(featureID string) []FeatureAsset {
	rows, err := s.db.Query(
		`SELECT a.id, a.owner_key, a.checksum, a.ext, a.kind, COALESCE(a.mime_type, ''), a.size_bytes, a.object_key,
		        a.is_public, a.created_at, a.updated_at,
		        l.feature_id, COALESCE(l.name, ''), COALESCE(l.description, ''), l.created_at
		 FROM feature_asset_links l
		 JOIN assets a ON a.id = l.asset_id
		 WHERE l.feature_id = $1
		 ORDER BY l.created_at`,
		featureID,
	)
	if err != nil {
		return nil
	}
	defer rows.Close()
	result := make([]FeatureAsset, 0)
	for rows.Next() {
		var fa FeatureAsset
		if err := rows.Scan(
			&fa.ID, &fa.OwnerKey, &fa.Checksum, &fa.Ext, &fa.Kind, &fa.MimeType, &fa.SizeBytes, &fa.ObjectKey,
			&fa.IsPublic, &fa.CreatedAt, &fa.UpdatedAt, &fa.FeatureID, &fa.Name, &fa.Description, &fa.LinkedAt,
		); err != nil {
			return result
		}
		result = append(result, fa)
	}
	return result
}
func (s *PostgresStore) PruneExpired(now time.Time) {
	_, _ = s.db.Exec(`DELETE FROM challenges WHERE expires_at < $1`, now)
	_, _ = s.db.Exec(`DELETE FROM sessions WHERE expires_at < $1`, now)
	_, _ = s.db.Exec(`DELETE FROM invitations WHERE expires_at < $1`, now)
}

func nullStr(s string) interface{} {
	if s == "" {
		return nil
	}
	return s
}

func isUniqueViolation(err error) bool {
	if err == nil {
		return false
	}
	s := err.Error()
	return strings.Contains(s, "duplicate key") || strings.Contains(s, "23505")
}