PR: Add filter to download files by size

Description

This PR addresses issue #1119 by adding the ability to filter downloads based on file size. It introduces two new flags to the download command: --min-size and --max-size.

Changes

1. New Utility: ParseBinaryBytes

• File: pkg/utils/byte.go
• Description: Added a helper function to parse human-readable size strings (e.g., "10MB", "1.5GB") into bytes.
• Tests: Added comprehensive unit tests in pkg/utils/byte_test.go.

2. Core Implementation

• File: app/dl/dl.go
  • Added MinSize and MaxSize fields to the Options struct.
• File: app/dl/iter.go
  • Integrated size filtering logic into the download iteration process.
  • Refactored filtering logic into a dedicated shouldSkip method for better readability and testability.
  • Added debug logging to trace skipped files.

3. CLI Updates

• File: cmd/dl.go
  • Added --min-size and --max-size flags to the dl command.

Usage Example

# Download only files smaller than 50MB
tdl dl -u https://t.me/c/12345/678 --max-size 50MB

# Download only files larger than 1GB
tdl dl -u https://t.me/c/12345/678 --min-size 1GB

Verification

• Unit Tests: verified ParseBinaryBytes with new tests in pkg/utils/byte_test.go.
• Logic Tests: verified filtering logic with TestIterShouldSkip in app/dl/iter_test.go.
• Manual Testing: Verified that the flags correctly filter files based on the specified size limits using sample downloads.