Download data by chunks without redownloading existing data

config/app.yaml

@@ -1,4 +1,7 @@
 framework:
+    cache:
+        prefix_seed: 'stochastix.download'
+
     messenger:
         transports:
             stochastix: '%env(MESSENGER_TRANSPORT_DSN)%'

config/services.yaml

@@ -16,3 +16,12 @@ services:
             - '../src/**/Exception'
             - '../src/**/Event'
             - '../src/**/Model'
+
+    stochastix.download.cancel.cache:
+        class: Symfony\Component\Cache\Adapter\FilesystemAdapter
+        arguments:
+            - 'stochastix.download.cancel'
+            - 3600
+            - '%kernel.project_dir%/data/.cache'
+        tags:
+            - { name: 'cache.pool', namespace: 'stochastix.download' }

docs/api.md

@@ -52,6 +52,27 @@ This document outlines the RESTful API endpoints provided by the `stochastix-cor
 ---
 ### Market Data
 
+* **`GET /api/data/exchanges`**
+    * **Description:** Retrieves a sorted list of all exchange IDs supported by the backend (via the CCXT library).
+    * **Requires:** None
+    * **Request Body:** None
+    * **Success Response:** `200 OK`
+    * **Example Success Response Body:**
+      ```json
+      [
+          "ace",
+          "alpaca",
+          "ascendex",
+          "bequant",
+          "bigone",
+          "binance",
+          "binancecoinm",
+          "binanceus",
+          "binanceusdm",
+          "bingx"
+      ]
+      ```
+
 * **`GET /api/data-availability`**
     * **Description:** Scans the server for available market data (`.stchx` files) and returns a manifest detailing available symbols, their timeframes, and the start/end dates for each dataset.
     * **Requires:** None
@@ -114,6 +135,21 @@ This document outlines the RESTful API endpoints provided by the `stochastix-cor
         * `400 Bad Request`: Invalid input (e.g., validation errors in the request body, end date before start date).
         * `500 Internal Server Error`: If the download message could not be dispatched to the queue.
 
+* **`DELETE /api/data/download/{jobId}`**
+    * **Description:** Requests the cancellation of a running download job. The cancellation may take a few moments to take effect, as it is checked between data chunk fetches.
+    * **Requires:** None
+    * **URL Parameters:**
+        * `jobId` (string, required): The unique ID of the download job to cancel.
+    * **Request Body:** None
+    * **Success Response:** `202 Accepted`
+    * **Example Success Response Body:**
+        ```json
+        {
+          "status": "cancellation_requested",
+          "jobId": "download_666c1e5a7b8d9"
+        }
+        ```
+    * **Error Responses:** None.
 
 * **`GET /api/data/inspect/{exchangeId}/{symbol}/{timeframe}`**
     * **Description:** Inspects a specific market data file (`.stchx`). Returns the file's header metadata, a sample of the first and last records, and a full data consistency validation report (checking for gaps, duplicates, and out-of-order records).

src/Command/DataDownloadCommand.php

@@ -62,6 +62,12 @@ protected function configure(): void
                 'E',
                 InputOption::VALUE_OPTIONAL,
                 'The UTC end date/time (Format: Y-m-d[THH:MM:SS]). Defaults to "now".'
+            )
+            ->addOption(
+                'force',
+                'f',
+                InputOption::VALUE_NONE,
+                'Force re-download and overwrite of the entire date range, even if data exists.'
             );
     }
 
@@ -74,6 +80,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             $exchange = $input->getArgument('exchange');
             $symbol = $input->getArgument('symbol');
             $timeframe = $input->getArgument('timeframe');
+            $forceOverwrite = $input->getOption('force');
 
             $startDateStr = $input->getOption('start-date');
             $endDateStr = $input->getOption('end-date');
@@ -89,6 +96,10 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 return Command::INVALID;
             }
 
+            if ($forceOverwrite) {
+                $io->warning('Force mode enabled: Existing data in the specified range will be overwritten.');
+            }
+
             $io->title('🚀 Stochastix OHLCV Data Downloader 🚀');
             $io->newLine();
             $io->section('Download Progress');
@@ -116,7 +127,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 $symbol,
                 $timeframe,
                 $startDate,
-                $endDate
+                $endDate,
+                $forceOverwrite
             );
 
             $this->progressBar->finish();

src/Domain/Backtesting/MessageHandler/RunBacktestMessageHandler.php

@@ -76,7 +76,14 @@ public function __invoke(RunBacktestMessage $message): void
 
     private function publishUpdate(string $topic, array $data): void
     {
-        $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
-        $this->mercureHub->publish($update);
+        try {
+            $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
+            $this->mercureHub->publish($update);
+        } catch (\Throwable $e) {
+            $this->logger->warning('Failed to publish update to Mercure. The backtest will continue.', [
+                'topic' => $topic,
+                'error' => $e->getMessage(),
+            ]);
+        }
     }
 }

src/Domain/Backtesting/Service/MultiTimeframeDataService.php

@@ -70,7 +70,7 @@ private function generateFilePath(string $exchangeId, string $symbol, string $ti
             rtrim($this->baseDataPath, '/'),
             strtolower($exchangeId),
             strtoupper($sanitizedSymbol),
-            strtolower($timeframe)
+            $timeframe
         );
     }
 }

src/Domain/Data/Controller/CancelDownloadAction.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Stochastix\Domain\Data\Controller;
+
+use Psr\Cache\CacheItemPoolInterface;
+use Psr\Cache\InvalidArgumentException;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\DependencyInjection\Attribute\Autowire;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Attribute\AsController;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[AsController]
+#[Route('/api/data/download/{jobId}', name: 'stochastix_api_data_cancel_download', methods: ['DELETE'])]
+class CancelDownloadAction extends AbstractController
+{
+    public function __construct(
+        #[Autowire(service: 'stochastix.download.cancel.cache')]
+        private readonly CacheItemPoolInterface $cache,
+    ) {
+    }
+
+    /**
+     * @throws InvalidArgumentException
+     */
+    public function __invoke(string $jobId): JsonResponse
+    {
+        $cacheKey = 'download.cancel.' . $jobId;
+        $item = $this->cache->getItem($cacheKey);
+
+        $item->set(true);
+        $item->expiresAfter(3600);
+        $this->cache->save($item);
+
+        return $this->json(
+            ['status' => 'cancellation_requested', 'jobId' => $jobId],
+            Response::HTTP_ACCEPTED
+        );
+    }
+}

src/Domain/Data/Controller/GetExchangesAction.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace Stochastix\Domain\Data\Controller;
+
+use Stochastix\Domain\Data\Service\MarketDataService;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpKernel\Attribute\AsController;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[AsController]
+#[Route('/api/data/exchanges', name: 'stochastix_api_data_exchanges', methods: ['GET'])]
+class GetExchangesAction extends AbstractController
+{
+    public function __construct(private readonly MarketDataService $marketDataService)
+    {
+    }
+
+    public function __invoke(): JsonResponse
+    {
+        return $this->json($this->marketDataService->getExchanges());
+    }
+}

src/Domain/Data/Dto/DownloadRequestDto.php

@@ -20,17 +20,16 @@ public function __construct(
         public string $startDate,
         #[Assert\Date(message: 'End date must be in Y-m-d format.')]
         public string $endDate,
+        public bool $forceOverwrite = false,
     ) {
     }
 
     public function validateDateRange(ExecutionContextInterface $context): void
     {
-        if ($this->startDate !== null && $this->endDate !== null) {
-            if ($this->endDate < $this->startDate) {
-                $context->buildViolation('End date must be after or the same as start date.')
-                    ->atPath('endDate')
-                    ->addViolation();
-            }
+        if ($this->startDate !== null && $this->endDate !== null && $this->endDate < $this->startDate) {
+            $context->buildViolation('End date must be after or the same as start date.')
+                ->atPath('endDate')
+                ->addViolation();
         }
     }
 }

src/Domain/Data/EventSubscriber/DownloadProgressSubscriber.php

@@ -2,15 +2,18 @@
 
 namespace Stochastix\Domain\Data\EventSubscriber;
 
+use Psr\Log\LoggerInterface;
 use Stochastix\Domain\Data\Event\DownloadProgressEvent;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Mercure\HubInterface;
 use Symfony\Component\Mercure\Update;
 
 final readonly class DownloadProgressSubscriber implements EventSubscriberInterface
 {
-    public function __construct(private HubInterface $mercureHub)
-    {
+    public function __construct(
+        private HubInterface $mercureHub,
+        private readonly LoggerInterface $logger,
+    ) {
     }
 
     public static function getSubscribedEvents(): array
@@ -40,7 +43,14 @@ public function onDownloadProgress(DownloadProgressEvent $event): void
             'message' => "Fetched {$event->recordsFetchedInBatch} records up to " . gmdate('Y-m-d H:i:s', $event->lastTimestamp),
         ];
 
-        $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
-        $this->mercureHub->publish($update);
+        try {
+            $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
+            $this->mercureHub->publish($update);
+        } catch (\Throwable $e) {
+            $this->logger->warning('Failed to publish progress update to Mercure.', [
+                'jobId' => $event->jobId,
+                'error' => $e->getMessage(),
+            ]);
+        }
     }
 }

src/Domain/Data/Exception/DownloadCancelledException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Stochastix\Domain\Data\Exception;
+
+class DownloadCancelledException extends DownloaderException
+{
+}

src/Domain/Data/Exception/EmptyHistoryException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace Stochastix\Domain\Data\Exception;
+
+class EmptyHistoryException extends ExchangeException
+{
+}

src/Domain/Data/MessageHandler/DownloadDataMessageHandler.php

@@ -3,6 +3,7 @@
 namespace Stochastix\Domain\Data\MessageHandler;
 
 use Psr\Log\LoggerInterface;
+use Stochastix\Domain\Data\Exception\DownloadCancelledException;
 use Stochastix\Domain\Data\Message\DownloadDataMessage;
 use Stochastix\Domain\Data\Service\OhlcvDownloader;
 use Symfony\Component\Mercure\HubInterface;
@@ -46,6 +47,7 @@ public function __invoke(DownloadDataMessage $message): void
                 $dto->timeframe,
                 $startDate,
                 $endDate,
+                $dto->forceOverwrite,
                 $jobId
             );
 
@@ -54,6 +56,9 @@ public function __invoke(DownloadDataMessage $message): void
                 'progress' => 100,
                 'message' => 'Download completed successfully.',
             ]);
+        } catch (DownloadCancelledException $e) {
+            $this->logger->info('Data download job {jobId} was cancelled.', ['jobId' => $jobId, 'reason' => $e->getMessage()]);
+            $this->publishUpdate($topic, ['status' => 'cancelled', 'message' => 'Download was cancelled by the user.']);
         } catch (\Throwable $e) {
             $this->logger->error('Data download job {jobId} failed: {message}', [
                 'jobId' => $jobId,
@@ -70,7 +75,14 @@ public function __invoke(DownloadDataMessage $message): void
 
     private function publishUpdate(string $topic, array $data): void
     {
-        $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
-        $this->mercureHub->publish($update);
+        try {
+            $update = new Update($topic, json_encode($data, JSON_THROW_ON_ERROR));
+            $this->mercureHub->publish($update);
+        } catch (\Throwable $e) {
+            $this->logger->warning('Failed to publish update to Mercure. The process will continue.', [
+                'topic' => $topic,
+                'error' => $e->getMessage(),
+            ]);
+        }
     }
 }