package postgres

import (
	"context"
	"database/sql"
	"errors"

	"github.com/google/uuid"
	"github.com/rwadurian/mpc-system/services/account/domain/entities"
	"github.com/rwadurian/mpc-system/services/account/domain/repositories"
	"github.com/rwadurian/mpc-system/services/account/domain/value_objects"
)

// RecoverySessionPostgresRepo implements RecoverySessionRepository using PostgreSQL
type RecoverySessionPostgresRepo struct {
	db *sql.DB
}

// NewRecoverySessionPostgresRepo creates a new RecoverySessionPostgresRepo
func NewRecoverySessionPostgresRepo(db *sql.DB) repositories.RecoverySessionRepository {
	return &RecoverySessionPostgresRepo{db: db}
}

// Create creates a new recovery session
func (r *RecoverySessionPostgresRepo) Create(ctx context.Context, session *entities.RecoverySession) error {
	query := `
		INSERT INTO account_recovery_sessions (id, account_id, recovery_type, old_share_type,
			new_keygen_session_id, status, requested_at, completed_at)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
	`

	var oldShareType *string
	if session.OldShareType != nil {
		s := session.OldShareType.String()
		oldShareType = &s
	}

	_, err := r.db.ExecContext(ctx, query,
		session.ID,
		session.AccountID.UUID(),
		session.RecoveryType.String(),
		oldShareType,
		session.NewKeygenSessionID,
		session.Status.String(),
		session.RequestedAt,
		session.CompletedAt,
	)

	return err
}

// GetByID retrieves a recovery session by ID
func (r *RecoverySessionPostgresRepo) GetByID(ctx context.Context, id string) (*entities.RecoverySession, error) {
	sessionID, err := uuid.Parse(id)
	if err != nil {
		return nil, entities.ErrRecoveryNotFound
	}

	query := `
		SELECT id, account_id, recovery_type, old_share_type,
			new_keygen_session_id, status, requested_at, completed_at
		FROM account_recovery_sessions
		WHERE id = $1
	`

	return r.scanSession(r.db.QueryRowContext(ctx, query, sessionID))
}

// GetByAccountID retrieves recovery sessions for an account
func (r *RecoverySessionPostgresRepo) GetByAccountID(ctx context.Context, accountID value_objects.AccountID) ([]*entities.RecoverySession, error) {
	query := `
		SELECT id, account_id, recovery_type, old_share_type,
			new_keygen_session_id, status, requested_at, completed_at
		FROM account_recovery_sessions
		WHERE account_id = $1
		ORDER BY requested_at DESC
	`

	return r.querySessions(ctx, query, accountID.UUID())
}

// GetActiveByAccountID retrieves active recovery sessions for an account
func (r *RecoverySessionPostgresRepo) GetActiveByAccountID(ctx context.Context, accountID value_objects.AccountID) (*entities.RecoverySession, error) {
	query := `
		SELECT id, account_id, recovery_type, old_share_type,
			new_keygen_session_id, status, requested_at, completed_at
		FROM account_recovery_sessions
		WHERE account_id = $1 AND status IN ('requested', 'in_progress')
		ORDER BY requested_at DESC
		LIMIT 1
	`

	return r.scanSession(r.db.QueryRowContext(ctx, query, accountID.UUID()))
}

// Update updates a recovery session
func (r *RecoverySessionPostgresRepo) Update(ctx context.Context, session *entities.RecoverySession) error {
	query := `
		UPDATE account_recovery_sessions
		SET recovery_type = $2, old_share_type = $3, new_keygen_session_id = $4,
			status = $5, completed_at = $6
		WHERE id = $1
	`

	var oldShareType *string
	if session.OldShareType != nil {
		s := session.OldShareType.String()
		oldShareType = &s
	}

	result, err := r.db.ExecContext(ctx, query,
		session.ID,
		session.RecoveryType.String(),
		oldShareType,
		session.NewKeygenSessionID,
		session.Status.String(),
		session.CompletedAt,
	)

	if err != nil {
		return err
	}

	rowsAffected, err := result.RowsAffected()
	if err != nil {
		return err
	}

	if rowsAffected == 0 {
		return entities.ErrRecoveryNotFound
	}

	return nil
}

// Delete deletes a recovery session
func (r *RecoverySessionPostgresRepo) Delete(ctx context.Context, id string) error {
	sessionID, err := uuid.Parse(id)
	if err != nil {
		return entities.ErrRecoveryNotFound
	}

	query := `DELETE FROM account_recovery_sessions WHERE id = $1`

	result, err := r.db.ExecContext(ctx, query, sessionID)
	if err != nil {
		return err
	}

	rowsAffected, err := result.RowsAffected()
	if err != nil {
		return err
	}

	if rowsAffected == 0 {
		return entities.ErrRecoveryNotFound
	}

	return nil
}

// scanSession scans a single recovery session row
func (r *RecoverySessionPostgresRepo) scanSession(row *sql.Row) (*entities.RecoverySession, error) {
	var (
		id                 uuid.UUID
		accountID          uuid.UUID
		recoveryType       string
		oldShareType       sql.NullString
		newKeygenSessionID sql.NullString
		status             string
		session            entities.RecoverySession
	)

	err := row.Scan(
		&id,
		&accountID,
		&recoveryType,
		&oldShareType,
		&newKeygenSessionID,
		&status,
		&session.RequestedAt,
		&session.CompletedAt,
	)

	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, entities.ErrRecoveryNotFound
		}
		return nil, err
	}

	session.ID = id
	session.AccountID = value_objects.AccountIDFromUUID(accountID)
	session.RecoveryType = value_objects.RecoveryType(recoveryType)
	session.Status = value_objects.RecoveryStatus(status)

	if oldShareType.Valid {
		st := value_objects.ShareType(oldShareType.String)
		session.OldShareType = &st
	}

	if newKeygenSessionID.Valid {
		if keygenID, err := uuid.Parse(newKeygenSessionID.String); err == nil {
			session.NewKeygenSessionID = &keygenID
		}
	}

	return &session, nil
}

// querySessions queries multiple recovery sessions
func (r *RecoverySessionPostgresRepo) querySessions(ctx context.Context, query string, args ...interface{}) ([]*entities.RecoverySession, error) {
	rows, err := r.db.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var sessions []*entities.RecoverySession
	for rows.Next() {
		var (
			id                 uuid.UUID
			accountID          uuid.UUID
			recoveryType       string
			oldShareType       sql.NullString
			newKeygenSessionID sql.NullString
			status             string
			session            entities.RecoverySession
		)

		err := rows.Scan(
			&id,
			&accountID,
			&recoveryType,
			&oldShareType,
			&newKeygenSessionID,
			&status,
			&session.RequestedAt,
			&session.CompletedAt,
		)

		if err != nil {
			return nil, err
		}

		session.ID = id
		session.AccountID = value_objects.AccountIDFromUUID(accountID)
		session.RecoveryType = value_objects.RecoveryType(recoveryType)
		session.Status = value_objects.RecoveryStatus(status)

		if oldShareType.Valid {
			st := value_objects.ShareType(oldShareType.String)
			session.OldShareType = &st
		}

		if newKeygenSessionID.Valid {
			if keygenID, err := uuid.Parse(newKeygenSessionID.String); err == nil {
				session.NewKeygenSessionID = &keygenID
			}
		}

		sessions = append(sessions, &session)
	}

	return sessions, rows.Err()
}