## 2026-02-25 Task 1: Add video URL validation helper

**Task**: Add `_test_video_url()` method to AnimeSamaDownloader

**What was implemented**:
- Method `_test_video_url(url: str) -> bool` added to end of AnimeSamaDownloader class
- Downloads first 10KB using HTTP Range header (`bytes=0-10240`)
- 10 second timeout handling
- Returns True if HTTP 200 and data > 0 bytes
- Returns False on timeout, connection error, or empty response
- Logs all validation results

**Issues encountered**:
- Subagent created duplicate imports and modified unrelated files
- Had to revert changes to other files
- Had to fix duplicate logger line
- Had to revert unintended get_download_link signature change

**Verification**:
- Valid URL (google.com): Returns True ✓
- Timeout URL (httpbin.org/delay/20): Returns False ✓
- Method exists: True ✓

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## 2026-02-25 Task 2: Implement player fallback logic

**Task**: Add `get_download_link_with_fallback()` method with player priority list

**What was implemented**:
- Added `__init__` method with cache initialization: `self._working_players = {}`
- Added `get_download_link_with_fallback()` method with:
  - Player priority list: ['vidmoly', 'sendvid', 'sibnet', 'lpayer']
  - Tries each player in order
  - Validates each URL with _test_video_url()
  - Caches working player per anime URL
  - Logs each player attempt (success/failure)
  - Returns (video_url, filename) on first success
  - Raises exception if all players fail

**Verification**:
- First player works: VidMoly URL returned ✓
- First fails, second works: SendVid URL returned ✓
- All fail: Exception raised ✓

---

## 2026-02-25 Task 3: Integrate fallback into get_download_link()

**Task**: Update `get_download_link()` to use fallback for pipe-separated URLs

**What was implemented**:
- Modified `get_download_link()` to call `get_download_link_with_fallback()` for pipe-separated URLs
- Direct URLs (no pipe) still use existing extraction flow for performance
- Backward compatibility maintained
- Fixed target_filename parameter to match download_manager expectations

**Verification**:
- Pipe URL triggers fallback: True ✓
- Direct URL skips fallback: True ✓

---

## 2026-02-25 Task 4: Add unit tests

**Task**: Create unit tests for fallback logic

**What was implemented**:
- Created `tests/test_anime_sama_fallback.py` with 10 tests:
  1. test_fallback_tries_players_in_priority_order
  2. test_caching_mechanism_stores_working_player
  3. test_all_players_failing_raises_exception
  4. test_test_video_url_returns_true_for_valid_url
  5. test_test_video_url_returns_false_for_invalid_url
  6. test_test_video_url_returns_false_for_empty_response
  7. test_test_video_url_returns_false_for_timeout
  8. test_test_video_url_returns_false_for_connection_error
  9. test_fallback_skips_invalid_player_url
  10. test_cache_not_used_without_anime_page_url

**Verification**:
- All 10 tests pass: ✓

---

## 2026-02-25 Task 5: Integration testing

**Task**: Test with real Anime-Sama URLs

**What was implemented**:
- Downloaded Frieren S1 E1 from anime-sama.tv
- Used pipe-separated URL format
- Download completed successfully

**Verification**:
- Download status: COMPLETED ✓
- File size: 321MB ✓
- Fallback logic working (SendVid used) ✓
