package authrequest

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"

	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/internal/model"
	"git.faercol.me/faercol/polyculeconnect/polyculeconnect/logger"
	"github.com/google/uuid"
)

var ErrNotFound = errors.New("backend not found")

const authRequestRows = `"id", "client_id", "backend_id", "scopes", "redirect_uri", "state", "nonce", "response_type", "creation_time"`

type AuthRequestDB interface {
	GetAuthRequestByID(ctx context.Context, id uuid.UUID) (*model.AuthRequest, error)
	CreateAuthRequest(ctx context.Context, req model.AuthRequest) error
}

type sqlAuthRequestDB struct {
	db *sql.DB
}

func (db *sqlAuthRequestDB) GetAuthRequestByID(ctx context.Context, id uuid.UUID) (*model.AuthRequest, error) {
	logger.L.Debugf("Getting auth request with id %s", id)
	query := fmt.Sprintf(`SELECT %s FROM "auth_request_2" WHERE "id" = ?`, authRequestRows)
	row := db.db.QueryRowContext(ctx, query, id)

	var res model.AuthRequest
	var scopesStr []byte

	if err := row.Scan(&res.ID, &res.ClientID, &res.BackendID, &scopesStr, &res.RedirectURI, &res.State, &res.Nonce, &res.ResponseType, &res.CreationDate); err != nil {
		return nil, fmt.Errorf("failed to get auth request from DB: %w", err)
	}
	if err := json.Unmarshal(scopesStr, &res.Scopes); err != nil {
		return nil, fmt.Errorf("invalid format for scopes: %w", err)
	}

	return &res, nil
}

func (db *sqlAuthRequestDB) CreateAuthRequest(ctx context.Context, req model.AuthRequest) error {
	logger.L.Debugf("Creating a new auth request between client app %s and backend %s", req.ClientID, req.BackendID)
	tx, err := db.db.BeginTx(ctx, nil)
	if err != nil {
		return fmt.Errorf("failed to start transaction: %w", err)
	}
	defer func() { _ = tx.Rollback() }()

	scopesStr, err := json.Marshal(req.Scopes)
	if err != nil {
		return fmt.Errorf("failed to serialize scopes: %w", err)
	}

	// TODO: when the old table is done, rename into auth_request
	query := fmt.Sprintf(`INSERT INTO "auth_request_2" (%s) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9)`, authRequestRows)
	_, err = tx.ExecContext(ctx, query,
		req.ID, req.ClientID, req.BackendID,
		scopesStr, req.RedirectURI, req.State,
		req.Nonce, req.ResponseType, req.CreationDate, req.AuthTime,
	)
	if err != nil {
		return fmt.Errorf("failed to insert in DB: %w", err)
	}

	if err := tx.Commit(); err != nil {
		return fmt.Errorf("failed to commit transaction: %w", err)
	}

	return nil
}

func New(db *sql.DB) *sqlAuthRequestDB {
	return &sqlAuthRequestDB{db: db}
}