# Timeline Feature Design

## Objective
Create a unified timeline view showing Tasks, Meals, Trello Cards, and Google Calendar Events, sorted chronologically.

## Data Sources
1.  **Tasks (Todoist):** From DB `tasks` table. Filter: `due_date` is not null.
2.  **Meals (PlanToEat):** From DB `meals` table. Filter: `date` is not null.
3.  **Cards (Trello):** From DB `cards` table. Filter: `due_date` is not null.
4.  **Google Calendar Events:** From `GoogleCalendarClient` (Live API).

## Backend Logic

### 1. Data Models (`internal/models/timeline.go`)
We need a polymorphic structure to hold different item types.

```go
type TimelineItemType string

const (
    ItemTypeTask  TimelineItemType = "task"
    ItemTypeMeal  TimelineItemType = "meal"
    ItemTypeCard  TimelineItemType = "card"
    ItemTypeEvent TimelineItemType = "event"
)

type TimelineItem struct {
    ID          string           `json:"id"`
    Type        TimelineItemType `json:"type"`
    Title       string           `json:"title"`
    Description string           `json:"description"`
    Time        time.Time        `json:"time"`
    AllDay      bool             `json:"all_day"`
    URL         string           `json:"url"`
    Meta        map[string]any   `json:"meta"` // Extra data like ProjectName, RecipeURL, etc.
}
```

### 2. Store Extensions (`internal/store/`)
Add methods to fetch items by date range.
*   `GetTasksByDateRange(start, end time.Time) ([]models.Task, error)`
*   `GetMealsByDateRange(start, end time.Time) ([]models.Meal, error)`
*   `GetCardsByDateRange(start, end time.Time) ([]models.Card, error)`

### 3. Logic Layer (`internal/handlers/timeline_logic.go`)
*   **Function:** `BuildTimeline(store Store, calendarClient *api.GoogleCalendarClient, start, end time.Time) ([]TimelineItem, error)`
*   **Aggregation:**
    1.  Fetch from Store (Tasks, Meals, Cards).
    2.  Fetch from Calendar API.
    3.  Convert all to `TimelineItem`.
    4.  **Meal Time Defaults:**
        *   Breakfast: 08:00
        *   Lunch: 12:00
        *   Dinner: 19:00
        *   Other: 12:00
    5.  Sort by `Time`.

### 4. HTTP Handler (`internal/handlers/timeline.go`)
*   **Route:** `GET /timeline`
*   **Params:** `start` (default: today), `days` (default: 7)
*   **Response:** Render `timeline-tab.html` partial.

## UI Design (`web/templates/partials/timeline-tab.html`)
*   **Structure:**
    *   Container
    *   Loop through Days
        *   Date Header (e.g., "Mon, Jan 2")
        *   List of Items
            *   Time Column (e.g., "14:00")
            *   Content Column (Icon + Title + Subtitle)
*   **Styling:**
    *   Use existing CSS variables.
    *   Distinct icons/colors for Tasks vs Meals vs Events.

## Files to Modify
1.  `internal/models/timeline.go` (New)
2.  `internal/store/store.go` (Interface update)
3.  `internal/store/sqlite.go` (Implementation update)
4.  `internal/handlers/timeline_logic.go` (New)
5.  `internal/handlers/timeline.go` (New)
6.  `web/templates/partials/timeline-tab.html` (New)
7.  `cmd/dashboard/main.go` (Route registration)