# Implementation Plan: Collection Detail Page Fix + library_id Filter

## Overview

Fix the broken `/collections/:id` page (inline JS bug) and add library_id support to the search API. This uses a hybrid approach: minimal TypeScript for client-only features, HTMX-like patterns for CRUD operations.

---

## Files to Modify

| File | Changes |
|------|---------|
| `templates/collections.templ` | Remove inline JS, add data attributes, add toggle UI |
| `web/src/collections.ts` | Add minimal TypeScript functions (~60 lines) |
| `internal/handlers/media.go` | Add library_id param to search handler |
| `internal/router/frontend.go` | (No changes needed - existing modals work) |

---

## Step 1: Update Search API to Accept library_id

### File: `internal/handlers/media.go`

**Find** (around line 1418-1442):
```go
// SearchMediaItems handles GET /api/media-items/search
func (mh *MediaHandler) SearchMediaItems(c echo.Context) error {
	query := c.QueryParam("q")
	userID := c.Get("user_id").(string)

	if query == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "query parameter 'q' is required"})
	}

	userUUID, err := uuid.Parse(userID)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid user id"})
	}

	limit := int32(50)
	offset := int32(0)

	searchPattern := "%" + query + "%"

	partialResults, err := mh.db.SearchMediaItems(c.Request().Context(), database.SearchMediaItemsParams{
		SearchPattern: pgtype.Text{String: searchPattern, Valid: true},
		UserID:        pgtype.UUID{Bytes: userUUID, Valid: true},
		Limit:         pgtype.Int4{Int32: limit, Valid: true},
		Offset:        pgtype.Int4{Int32: offset, Valid: true},
	})
```

**Replace with**:
```go
// SearchMediaItems handles GET /api/media-items/search
func (mh *MediaHandler) SearchMediaItems(c echo.Context) error {
	query := c.QueryParam("q")
	userID := c.Get("user_id").(string)
	libraryID := c.QueryParam("library_id") // Optional: filter by library

	if query == "" {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "query parameter 'q' is required"})
	}

	userUUID, err := uuid.Parse(userID)
	if err != nil {
		return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid user id"})
	}

	// Validate library_id if provided
	var libUUID *uuid.UUID
	if libraryID != "" {
		lib, err := uuid.Parse(libraryID)
		if err != nil {
			return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid library_id"})
		}
		libUUID = &lib
	}

	limit := int32(50)
	offset := int32(0)

	searchPattern := "%" + query + "%"

	// Build params - conditionally add library_id filter
	params := database.SearchMediaItemsParams{
		SearchPattern: pgtype.Text{String: searchPattern, Valid: true},
		UserID:        pgtype.UUID{Bytes: userUUID, Valid: true},
		Limit:         pgtype.Int4{Int32: limit, Valid: true},
		Offset:        pgtype.Int4{Int32: offset, Valid: true},
	}

	// If library_id provided, add to query params
	if libUUID != nil {
		params.LibraryID = pgtype.UUID{Bytes: *libUUID, Valid: true}
	}

	partialResults, err := mh.db.SearchMediaItems(c.Request().Context(), params)
```

**Note**: You need to check if `SearchMediaItemsParams` in `database.SearchMediaItemsParams` already has a `LibraryID` field. If not, you'll need to add it to the SQL query.

---

## Step 2: Add library_id to SQL Query (if needed)

### File: `internal/database/queries.sql`

**Find** the `SearchMediaItems` query:
```sql
-- name: SearchMediaItems :many
SELECT ...
FROM media_items mi
WHERE ...
```

**Add** library_id filter (if not present):
```sql
-- name: SearchMediaItems :many
SELECT mi.id, mi.user_id, mi.title, mi.author, mi.cover_image_path, mi.library_id, ...
FROM media_items mi
WHERE ...
  AND ($1::uuid IS NULL OR mi.library_id = $1::uuid)  -- Add this filter
```

**Update** the `SearchMediaItemsParams` struct in `queries.sql.go` if needed to include LibraryID.

---

## Step 3: Remove Inline JS from Template

### File: `templates/collections.templ`

**Find** the inline script block (lines 255-520):
```go
			<script>
            let collectionId = '{ collection.ID }';
            let selectedBooks = new Set();
            let booksToRemove = new Set();
            let allBooks = [
                { range books }{
                    {
                        id: '{ book.MediaItemID }',
                        title: '{ book.Title }',
                        author: '{ book.Author }',
                        cover: '{ book.CoverImagePath }'
                    },
                }{ end }
            ];
            let ws = null;

            function backToCollections() {
                window.location.href = '/collections';
            }

            // ... 265 lines of JavaScript ...
        </script>
```

**Replace with** a hidden data element (add after the `<body>` tag or where appropriate):
```go
		<!-- Collection data for JavaScript -->
		<div id="collection-data"
		     data-id="{ collection.ID }"
		     data-library-id="{ libraryID }"
		     style="display: none;">
		</div>

		<!-- Include compiled TypeScript -->
		<script src="/static/collections.js"></script>
```

**Note**: You need to pass `libraryID` to the template. Check the handler in `frontend.go` that renders `CollectionDetail` and add `libraryID` to the template data.

---

## Step 4: Add Toggle UI to Add Books Modal

### File: `templates/collections.templ`

**Find** the Add Books modal (around line 157):
```go
						<button onclick="showAddBooksModal()" class="btn-primary px-4 py-2 rounded-lg">
							➕ Add Books
						</button>
```

**Add** the toggle after this button:
```go
						<button onclick="showAddBooksModal()" class="btn-primary px-4 py-2 rounded-lg">
							➕ Add Books
						</button>
						{# Toggle only shows when library_id is present - handled by JS #}
```

**Find** the Add Books modal content (around line 339 in generated, find in source):
```go
<div id="add-books-modal" ...>
	...
	<p class="mb-4" style="color: var(--text-secondary)">Search and select books to add to this collection.</p>
	<div class="mb-4">
		<input type="text" id="book-search" placeholder="Search books..." ...>
	</div>
	<div id="book-results" ...>
```

**Replace with**:
```go
<div id="add-books-modal" ...>
	...
	<p class="mb-4" style="color: var(--text-secondary)">Search and select books to add to this collection.</p>
	
	<!-- Library filter toggle - hidden by default, shown by JS when library_id present -->
	<div id="library-filter-container" class="mb-4 hidden">
		<label class="flex items-center gap-2 text-sm" style="color: var(--text-secondary);">
			<input type="checkbox" id="filter-by-library" class="w-4 h-4">
			<span>Only show books from this library</span>
		</label>
	</div>
	
	<div class="mb-4">
		<input type="text" id="book-search" placeholder="Search books..." ...>
	</div>
	<div id="book-results" ...>
```

---

## Step 5: Add Minimal TypeScript Functions

### File: `web/src/collections.ts`

**Add** at the end of the file:

```typescript
// ============================================================================
// Collection Detail Page - Minimal TypeScript (~60 lines)
// ============================================================================

interface BookItem {
  id: string;
  title: string;
  author: string;
  cover: string;
}

let collectionId = "";
let libraryId = "";
let selectedBooks = new Set<string>();
let booksToRemove = new Set<string>();

// Initialize from data attributes (called on page load)
function initCollectionDetail(): void {
  const dataEl = document.getElementById("collection-data");
  if (dataEl) {
    collectionId = dataEl.dataset.id || "";
    libraryId = dataEl.dataset.libraryId || "";
    
    // Show/hide library filter toggle based on whether library_id is present
    const filterContainer = document.getElementById("library-filter-container");
    if (filterContainer) {
      if (libraryId) {
        filterContainer.classList.remove("hidden");
        // Default: checked (filter by library)
        const checkbox = document.getElementById("filter-by-library") as HTMLInputElement;
        if (checkbox) checkbox.checked = true;
      } else {
        filterContainer.classList.add("hidden");
      }
    }
  }
}

// Get current library filter setting
function getLibraryFilterParam(): string {
  if (!libraryId) return "";
  
  const checkbox = document.getElementById("filter-by-library") as HTMLInputElement;
  if (checkbox && checkbox.checked) {
    return `&library_id=${libraryId}`;
  }
  return "";
}

// Modal functions (called from onclick attributes)
function showAddBooksModal(): void {
  const modal = document.getElementById("add-books-modal");
  if (modal) modal.classList.remove("hidden");
  selectedBooks.clear();
  
  const results = document.getElementById("book-results");
  if (results) {
    results.innerHTML = '<p class="text-sm" style="color: var(--text-secondary)">Enter at least 2 characters to search.</p>';
  }
}

function hideAddBooksModal(): void {
  const modal = document.getElementById("add-books-modal");
  if (modal) modal.classList.add("hidden");
  
  const searchInput = document.getElementById("book-search") as HTMLInputElement;
  if (searchInput) searchInput.value = "";
  
  const results = document.getElementById("book-results");
  if (results) results.innerHTML = "";
  
  selectedBooks.clear();
}

// Search books - now includes library filter
async function searchBooks(): Promise<void> {
  const searchInput = document.getElementById("book-search") as HTMLInputElement;
  const container = document.getElementById("book-results");
  if (!searchInput || !container) return;

  const searchTerm = searchInput.value;
  if (searchTerm.length < 2) {
    container.innerHTML = '<p class="text-sm" style="color: var(--text-secondary)">Enter at least 2 characters to search.</p>';
    return;
  }

  container.innerHTML = '<p class="text-sm" style="color: var(--text-secondary)">Searching...</p>';

  const libraryFilter = getLibraryFilterParam();
  const token = localStorage.getItem("token");
  
  try {
    const response = await fetch(`/api/media-items/search?q=${encodeURIComponent(searchTerm)}${libraryFilter}`, {
      headers: { Authorization: `Bearer ${token}` },
    });
    const result = await response.json();

    if (result.length > 0) {
      let html = '<div class="space-y-2">';
      result.slice(0, 50).forEach((book: any) => {
        const isSelected = selectedBooks.has(book.media_item_id);
        const checkedAttr = isSelected ? "checked" : "";
        const authorHtml = book.author ? `<div class="text-xs" style="color: var(--text-secondary)">${book.author}</div>` : "";
        const libraryBadge = book.library_id === libraryId ? '<span class="text-xs px-1 bg-blue-500 text-white rounded">This Library</span>' : '';
        
        html += `
          <div class="flex items-center gap-3 p-2 rounded cursor-pointer hover:opacity-80"
               style="background-color: var(--bg-primary);"
               onclick="toggleBookSelection('${book.media_item_id}')">
            <input type="checkbox" ${checkedAttr} class="w-4 h-4">
            <img src="${book.cover_image_path || "/static/placeholder-book.svg"}"
                 alt="Cover" class="w-10 h-14 object-cover rounded">
            <div class="flex-1">
              <div class="text-sm font-medium" style="color: var(--text-primary)">${book.title}</div>
              ${authorHtml}
            </div>
            ${libraryBadge}
          </div>
        `;
      });
      html += "</div>";
      container.innerHTML = html;
    } else {
      container.innerHTML = '<p class="text-sm" style="color: var(--text-secondary)">No books found</p>';
    }
  } catch (error) {
    container.innerHTML = '<p class="text-sm" style="color: var(--error)">Failed to search books</p>';
  }
}

// Toggle book selection
function toggleBookSelection(bookId: string): void {
  if (selectedBooks.has(bookId)) {
    selectedBooks.delete(bookId);
  } else {
    selectedBooks.add(bookId);
  }
  searchBooks();
}

// Add selected books to collection
async function addSelectedBooks(): Promise<void> {
  if (selectedBooks.size === 0) {
    (window as any).showToast?.("Please select at least one book", "error");
    return;
  }

  const bookIds = Array.from(selectedBooks);
  const token = localStorage.getItem("token");

  try {
    const response = await fetch(`/api/collections/${collectionId}/books`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${token}`,
      },
      body: JSON.stringify({ book_ids: bookIds }),
    });

    if (response.ok) {
      (window as any).showToast?.(`Added ${bookIds.length} book(s) to collection`, "success");
      hideAddBooksModal();
      location.reload();
    } else {
      (window as any).showToast?.("Failed to add books", "error");
    }
  } catch (error) {
    (window as any).showToast?.("Failed to add books", "error");
  }
}

// Remove single book from collection
async function removeBook(bookId: string): Promise<void> {
  if (!confirm("Remove this book from the collection?")) return;

  const token = localStorage.getItem("token");

  try {
    const response = await fetch(`/api/collections/${collectionId}/books/${bookId}`, {
      method: "DELETE",
      headers: { Authorization: `Bearer ${token}` },
    });

    if (response.ok) {
      (window as any).showToast?.("Book removed from collection", "success");
      location.reload();
    } else {
      (window as any).showToast?.("Failed to remove book", "error");
    }
  } catch (error) {
    (window as any).showToast?.("Failed to remove book", "error");
  }
}

// Bulk remove functions
function toggleBookForRemoval(bookId: string): void {
  if (booksToRemove.has(bookId)) {
    booksToRemove.delete(bookId);
  } else {
    booksToRemove.add(bookId);
  }
  updateSelectedCount();
}

function updateSelectedCount(): void {
  const count = booksToRemove.size;
  const countSpan = document.getElementById("selected-count");
  const removeBtn = document.getElementById("bulk-remove-btn") as HTMLButtonElement;

  if (count > 0) {
    if (countSpan) {
      countSpan.textContent = `${count} selected`;
      countSpan.classList.remove("hidden");
    }
    if (removeBtn) removeBtn.disabled = false;
  } else {
    if (countSpan) countSpan.classList.add("hidden");
    if (removeBtn) removeBtn.disabled = true;
  }
}

async function removeSelectedBooks(): Promise<void> {
  if (booksToRemove.size === 0) {
    (window as any).showToast?.("No books selected", "error");
    return;
  }

  if (!confirm(`Remove ${booksToRemove.size} book(s) from the collection?`)) return;

  const bookIds = Array.from(booksToRemove);
  const token = localStorage.getItem("token");

  try {
    const response = await fetch(`/api/collections/${collectionId}/books/bulk-remove`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Authorization: `Bearer ${token}`,
      },
      body: JSON.stringify({ book_ids: bookIds }),
    });

    const result = await response.json();
    if (result.removed > 0) {
      (window as any).showToast?.(`Removed ${result.removed} book(s) from collection`, "success");
      location.reload();
    } else {
      (window as any).showToast?.("Failed to remove books", "error");
    }
  } catch (error) {
    (window as any).showToast?.("Failed to remove books", "error");
  }
}

// Client-side search filter for displayed books
function filterCollectionBooks(): void {
  const searchTerm = (document.getElementById("collection-search") as HTMLInputElement)?.value.toLowerCase() || "";
  const booksContainer = document.getElementById("books-container");
  if (!booksContainer) return;

  const bookCards = booksContainer.children;
  for (let i = 0; i < bookCards.length; i++) {
    const card = bookCards[i] as HTMLElement;
    if (card.id === "empty-state") continue;

    const titleEl = card.querySelector(".font-semibold");
    const authorEl = card.querySelector(".text-sm");
    const title = titleEl?.textContent?.toLowerCase() || "";
    const author = authorEl?.textContent?.toLowerCase() || "";

    const matches = title.includes(searchTerm) || author.includes(searchTerm);
    card.style.display = matches || searchTerm === "" ? "" : "none";
  }
}

// Export functions globally
(window as any).initCollectionDetail = initCollectionDetail;
(window as any).showAddBooksModal = showAddBooksModal;
(window as any).hideAddBooksModal = hideAddBooksModal;
(window as any).searchBooks = searchBooks;
(window as any).toggleBookSelection = toggleBookSelection;
(window as any).addSelectedBooks = addSelectedBooks;
(window as any).removeBook = removeBook;
(window as any).toggleBookForRemoval = toggleBookForRemoval;
(window as any).updateSelectedCount = updateSelectedCount;
(window as any).removeSelectedBooks = removeSelectedBooks;
(window as any).filterCollectionBooks = filterCollectionBooks;

// Auto-initialize
if (document.readyState === "loading") {
  document.addEventListener("DOMContentLoaded", initCollectionDetail);
} else {
  initCollectionDetail();
}
```

---

## Step 6: Update Handler to Pass libraryID to Template

### File: `internal/router/frontend.go`

**Find** the collection detail handler (around line 420):
```go
// Render the CollectionDetail template
var buf bytes.Buffer
err = templates.CollectionDetail(user, colData, books).Render(c.Request().Context(), &buf)
```

**Replace with**:
```go
// Get library_id from query params for template
libraryID := c.QueryParam("library_id")

// Render the CollectionDetail template
var buf bytes.Buffer
err = templates.CollectionDetail(user, colData, books, libraryID).Render(c.Request().Context(), &buf)
```

**Note**: You may need to update the `CollectionDetail` function signature in `templates/collections.templ` to accept `libraryID` parameter.

---

## Step 7: Update Template to Accept libraryID

### File: `templates/collections.templ`

**Find** the CollectionDetail function signature:
```go
func CollectionDetail(user User, collection CollectionData, books []handlers.BookInfo) templ.Component {
```

**Replace with**:
```go
func CollectionDetail(user User, collection CollectionData, books []handlers.BookInfo, libraryID string) templ.Component {
```

---

## Summary of Changes

| Step | File | Lines Changed | Purpose |
|------|------|---------------|---------|
| 1 | `internal/handlers/media.go` | ~15 | Add library_id param to search |
| 2 | `internal/database/queries.sql` | ~2 | Add library_id filter to SQL |
| 3 | `templates/collections.templ` | -265 + 20 | Remove inline JS, add data attributes |
| 4 | `templates/collections.templ` | ~15 | Add toggle UI to modal |
| 5 | `web/src/collections.ts` | +~180 | Add minimal TypeScript |
| 6 | `internal/router/frontend.go` | ~5 | Pass libraryID to template |
| 7 | `templates/collections.templ` | ~3 | Accept libraryID in function signature |

---

## Testing Checklist

- [ ] Navigate to `/collections/:id` - page loads without JS errors
- [ ] Navigate to `/collections/:id?library_id=xxx` - page loads with toggle visible
- [ ] Click "Add Books" - modal opens
- [ ] Search in modal - results appear
- [ ] With library_id + toggle checked - only books from that library shown
- [ ] With library_id + toggle unchecked - all books shown
- [ ] Add book to collection - success toast + page reloads
- [ ] Remove book from collection - success toast + page reloads
- [ ] Search within collection - books filter client-side

---

## Notes

- The WebSocket real-time sync was removed from the TypeScript for simplicity. Can be added back if needed.
- The toggle default is "checked" (filter by library) when library_id is present, matching the dashboard context.
- The existing API handlers (`AddBooks`, `RemoveBook`, `BulkRemoveBooks`) don't need changes - they work with or without library_id.