Milestone 1 v2 stabilization

[cyberlog69]

PR Title

feat: Milestone 1 - DownloaderV2 stabilization, legacy V1 retirement, and test coverage

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Description

Overview

This PR completes Milestone 1 of the v2.0 architecture overhaul. It fully deprecates and removes the legacy single-job Downloader (V1) components, migrates all remaining pages and background receivers to DownloaderV2, refines custom command execution and restart logic, adds multi-task notification action handling (cancel/restart), and introduces comprehensive unit tests for task states, transitions, and queue serialization.

Net result: -1,103 lines of obsolete code removed while providing full concurrency support and test coverage.

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Key Changes

1. 🗑️ Legacy V1 Retirement & Technical Debt Cleanup

• Safely deleted obsolete V1 classes:
  • Removed legacy single-job Downloader.kt (-573 lines).
  • Removed legacy DownloadPage.kt (-805 lines) and HomePageViewModel.kt (-145 lines).
  • Removed stale imports and references from App.kt and AppEntry.kt.
• Migrated command & utility pages:
  • TaskListPage.kt: Switched task listing, creation, and cancellation to use DownloaderV2.getTaskStateMap(), enqueue(), and cancel().
  • TaskLogPage.kt: Updated live log viewing, process cancellation, and restart handling to read from and dispatch to DownloaderV2.
  • YtdlpUpdater.kt: Replaced checks against legacy Downloader.downloaderState with active queue inspection from DownloaderV2.

2. ⚡ DownloaderV2 Polish & Notification Actions

• Custom Command Lifecycle & Restart Fix (DownloaderV2.kt):
  • Fixed Task.download() to evaluate and execute custom commands prior to null-checking info (commands don't have video metadata).
  • Updated Task.execute() to accept both Idle (fresh start) and ReadyWithInfo (restart after cancel/error).
• Multi-Task Notification Handling:
  • Added ACTION_RESTART_TASK support to NotificationActionReceiver.kt so individual tasks can be restarted straight from error notifications.
  • Updated NotificationUtil.kt to accept a taskId in notifyError and attach a Restart action alongside the error report button.

3. 🧪 Testing & Quality Assurance

• TaskFactoryTest.kt: Unit tests for playlist item extraction and custom command factory methods.
• TaskStateTransitionTest.kt:
  • Tests queue priority sorting (Running < ReadyWithInfo < FetchingInfo < Idle < Canceled < Error < Completed).
  • Validates state transitions and restart action mapping (FetchInfo -> Idle, Download -> ReadyWithInfo).
  • Validates custom command lifecycle states.
• TaskBackupRestoreTest.kt:
  • Tests Map<Task, Task.State> serialization and deserialization via Kotlinx Serialization (allowStructuredMapKeys = true).
  • Tests queue recovery logic in enqueueFromBackup().

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Verification & Testing

• Ran :app:testGenericDebugUnitTest across all test classes:
  • TaskFactoryTest: PASSED
  • TaskStateTransitionTest: PASSED
  • TaskBackupRestoreTest: PASSED
  • ExampleUnitTest: PASSED
• Verified build and packaging with Java 21 / AGP 8.10.

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Diff Summary

20 files changed, 615 insertions(+), 1718 deletions(-)