# Mantimon TCG Frontend - AI Agent Guidelines

Guidelines for AI agents working on the frontend codebase.

## Tech Stack

| Technology | Purpose |
|------------|---------|
| Vue 3 | UI framework (Composition API + `<script setup>`) |
| Phaser 3 | Game canvas (matches, pack opening) |
| TypeScript | Type safety (strict mode) |
| Pinia | State management |
| Tailwind CSS | Styling (mobile-first) |
| Socket.io-client | Real-time communication |
| Vite | Build tool |
| Vitest | Unit/component testing |

---

## Quick Commands

```bash
npm run dev          # Start dev server
npm run build        # Production build
npm run preview      # Preview production build
npm run test         # Run tests
npm run test:watch   # Run tests in watch mode
npm run lint         # ESLint
npm run typecheck    # TypeScript check
```

---

## Project Structure

```
src/
├── api/              # API client and composables
│   ├── client.ts     # Base HTTP client with auth
│   └── types.ts      # API response types
├── assets/           # Static assets, global CSS
├── components/       # Reusable Vue components
│   ├── ui/           # Generic UI (Button, Modal, Toast)
│   ├── cards/        # Card display components
│   ├── deck/         # Deck builder components
│   └── game/         # Game UI overlays
├── composables/      # Vue composables (useAuth, useDecks, etc.)
├── game/             # Phaser game code
│   ├── scenes/       # Phaser scenes
│   ├── objects/      # Game objects (Card, Board)
│   ├── animations/   # Animation helpers
│   └── bridge.ts     # Vue-Phaser communication
├── layouts/          # Layout components
├── pages/            # Route pages
├── router/           # Vue Router config
├── socket/           # Socket.IO client
├── stores/           # Pinia stores
├── types/            # TypeScript types
└── utils/            # Utility functions
```

---

## Code Style

### Vue Components

**Single File Component structure:**
```vue
<script setup lang="ts">
// 1. Imports (Vue, then external, then local)
import { ref, computed, onMounted } from 'vue'

import { useGameStore } from '@/stores/game'
import type { Card } from '@/types'

// 2. Props and emits
const props = defineProps<{
  cardId: string
  size?: 'sm' | 'md' | 'lg'
}>()

const emit = defineEmits<{
  click: [cardId: string]
}>()

// 3. Composables and stores
const gameStore = useGameStore()

// 4. Reactive state
const isHovered = ref(false)

// 5. Computed
const card = computed(() => gameStore.getCard(props.cardId))

// 6. Methods
function handleClick() {
  emit('click', props.cardId)
}

// 7. Lifecycle
onMounted(() => {
  // ...
})
</script>

<template>
  <!-- Single root element preferred -->
  <div
    class="card"
    :class="{ 'card--hovered': isHovered }"
    @click="handleClick"
    @mouseenter="isHovered = true"
    @mouseleave="isHovered = false"
  >
    <slot />
  </div>
</template>

<style scoped>
/* Component-specific styles if Tailwind isn't enough */
</style>
```

### TypeScript

**Use strict typing:**
```typescript
// Good - explicit types
interface CardProps {
  cardId: string
  size?: 'sm' | 'md' | 'lg'
}

// Good - type imports
import type { Card, GameState } from '@/types'

// Good - const assertions for literals
const SIZES = ['sm', 'md', 'lg'] as const
type Size = typeof SIZES[number]

// Avoid - any
const data: any = response  // NO
const data: unknown = response  // OK if you'll narrow it
```

### Naming Conventions

| Type | Convention | Example |
|------|------------|---------|
| Components | PascalCase | `CardDisplay.vue`, `DeckBuilder.vue` |
| Composables | camelCase with `use` prefix | `useAuth.ts`, `useDeckValidation.ts` |
| Stores | camelCase with descriptive name | `auth.ts`, `game.ts` |
| Types/Interfaces | PascalCase | `Card`, `GameState`, `ApiResponse` |
| Constants | UPPER_SNAKE_CASE | `MAX_HAND_SIZE`, `API_BASE_URL` |
| CSS classes | kebab-case (BEM optional) | `card-display`, `card-display--active` |

---

## Pinia Stores

**Use setup store syntax:**
```typescript
// stores/game.ts
import { defineStore } from 'pinia'
import { ref, computed } from 'vue'
import type { GameState } from '@/types'

export const useGameStore = defineStore('game', () => {
  // State
  const gameState = ref<GameState | null>(null)
  const isConnected = ref(false)

  // Getters (computed)
  const myHand = computed(() => gameState.value?.myHand ?? [])
  const isMyTurn = computed(() => gameState.value?.currentPlayer === 'me')

  // Actions
  function setGameState(state: GameState) {
    gameState.value = state
  }

  function clearGame() {
    gameState.value = null
    isConnected.value = false
  }

  return {
    // State
    gameState,
    isConnected,
    // Getters
    myHand,
    isMyTurn,
    // Actions
    setGameState,
    clearGame,
  }
})
```

---

## Composables

**Pattern for API composables:**
```typescript
// composables/useDecks.ts
import { ref } from 'vue'
import { apiClient } from '@/api/client'
import type { Deck, DeckCreate } from '@/types'

export function useDecks() {
  const decks = ref<Deck[]>([])
  const isLoading = ref(false)
  const error = ref<string | null>(null)

  async function fetchDecks() {
    isLoading.value = true
    error.value = null
    try {
      decks.value = await apiClient.get<Deck[]>('/api/decks')
    } catch (e) {
      error.value = e instanceof Error ? e.message : 'Failed to fetch decks'
    } finally {
      isLoading.value = false
    }
  }

  async function createDeck(data: DeckCreate) {
    isLoading.value = true
    error.value = null
    try {
      const deck = await apiClient.post<Deck>('/api/decks', data)
      decks.value.push(deck)
      return deck
    } catch (e) {
      error.value = e instanceof Error ? e.message : 'Failed to create deck'
      throw e
    } finally {
      isLoading.value = false
    }
  }

  return {
    decks,
    isLoading,
    error,
    fetchDecks,
    createDeck,
  }
}
```

---

## Vue-Phaser Integration

**Phaser is for rendering only. Game logic lives in backend.**

### Communication Pattern

```typescript
// Vue -> Phaser (intentions)
phaserGame.value?.events.emit('card:play', { cardId, targetZone })
phaserGame.value?.events.emit('attack:select', { attackIndex })

// Phaser -> Vue (completions/UI requests)
phaserGame.value?.events.on('animation:complete', handleAnimationComplete)
phaserGame.value?.events.on('card:clicked', handleCardClicked)
```

### State Sync

```typescript
// Phaser scene reads from Pinia store
import { useGameStore } from '@/stores/game'

class MatchScene extends Phaser.Scene {
  private gameStore = useGameStore()

  update() {
    // React to store changes
    if (this.gameStore.gameState) {
      this.renderState(this.gameStore.gameState)
    }
  }
}
```

---

## Tailwind Guidelines

**Mobile-first responsive:**
```html
<!-- Base styles for mobile, override for larger screens -->
<div class="p-2 md:p-4 lg:p-6">
  <div class="grid grid-cols-2 md:grid-cols-3 lg:grid-cols-4">
    <!-- ... -->
  </div>
</div>
```

**Use design system colors:**
```html
<!-- Pokemon type colors defined in tailwind.config.js -->
<div class="bg-type-fire text-white">Fire Type</div>
<div class="bg-type-water text-white">Water Type</div>

<!-- UI colors -->
<button class="bg-primary hover:bg-primary-dark">Action</button>
```

---

## Testing

**Component tests with Vitest + Vue Test Utils:**
```typescript
import { describe, it, expect } from 'vitest'
import { mount } from '@vue/test-utils'
import CardDisplay from '@/components/cards/CardDisplay.vue'

describe('CardDisplay', () => {
  it('renders card name', () => {
    /**
     * Test that the card component displays the card name.
     *
     * Card names must be visible for players to identify cards
     * in their hand and on the board.
     */
    const wrapper = mount(CardDisplay, {
      props: { card: { id: '1', name: 'Pikachu', hp: 60 } }
    })
    expect(wrapper.text()).toContain('Pikachu')
  })

  it('emits click event with card id', async () => {
    /**
     * Test that clicking a card emits the correct event.
     *
     * Card clicks drive all game interactions - playing cards,
     * selecting targets, viewing details.
     */
    const wrapper = mount(CardDisplay, {
      props: { card: { id: '1', name: 'Pikachu', hp: 60 } }
    })
    await wrapper.trigger('click')
    expect(wrapper.emitted('click')?.[0]).toEqual(['1'])
  })
})
```

---

## Critical Rules

1. **Mobile-first** - Base styles for mobile, use `md:` and `lg:` for larger screens
2. **TypeScript strict** - No `any`, explicit types for props/emits/returns
3. **Composition API only** - No Options API, use `<script setup>`
4. **Phaser for rendering** - No game logic in Phaser, only visualization
5. **Backend is authoritative** - Never trust client state for game logic
6. **Test docstrings** - Every test needs a docstring explaining what and why

---

## Path Aliases

```typescript
// Use @/ for src/
import { useAuth } from '@/composables/useAuth'
import CardDisplay from '@/components/cards/CardDisplay.vue'
import type { Card } from '@/types'

// Don't use relative paths for deeply nested imports
import { useAuth } from '../../../composables/useAuth'  // NO
```

---

## Environment Variables

```bash
# .env.development
VITE_API_BASE_URL=http://localhost:8000
VITE_WS_URL=http://localhost:8000

# .env.production
VITE_API_BASE_URL=https://api.pocket.manticorum.com
VITE_WS_URL=https://api.pocket.manticorum.com
```

**Access in code:**
```typescript
const apiUrl = import.meta.env.VITE_API_BASE_URL
```

---

## Common Patterns

### Loading States
```vue
<template>
  <div v-if="isLoading" class="flex justify-center p-8">
    <LoadingSpinner />
  </div>
  <div v-else-if="error" class="text-error p-4">
    {{ error }}
  </div>
  <div v-else>
    <!-- Content -->
  </div>
</template>
```

### Route Guards
```typescript
// router/guards.ts
export function requireAuth(to, from, next) {
  const auth = useAuthStore()
  if (!auth.isAuthenticated) {
    next({ name: 'Login', query: { redirect: to.fullPath } })
  } else {
    next()
  }
}
```

### API Error Handling
```typescript
try {
  await apiClient.post('/api/games', data)
} catch (e) {
  if (e instanceof ApiError) {
    if (e.status === 401) {
      // Token expired, redirect to login
      auth.logout()
    } else {
      toast.error(e.message)
    }
  }
}
```

---

## Backend API Reference

### REST Endpoints

**Auth** (`/api/auth/`)
| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/auth/google` | Start Google OAuth (redirect) |
| GET | `/auth/google/callback` | Google OAuth callback |
| GET | `/auth/discord` | Start Discord OAuth (redirect) |
| GET | `/auth/discord/callback` | Discord OAuth callback |
| POST | `/auth/refresh` | Refresh access token |
| POST | `/auth/logout` | Revoke refresh token |
| POST | `/auth/logout-all` | Revoke all user tokens |
| GET | `/auth/link/google` | Link Google account (authed) |
| GET | `/auth/link/discord` | Link Discord account (authed) |

**Users** (`/api/users/`)
| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/users/me` | Get current user profile |
| PATCH | `/users/me` | Update profile (display_name, avatar_url) |
| GET | `/users/me/linked-accounts` | List linked OAuth accounts |
| DELETE | `/users/me/link/{provider}` | Unlink OAuth provider |
| GET | `/users/me/sessions` | Get active session count |
| GET | `/users/me/starter-status` | Check if starter deck selected |
| POST | `/users/me/starter-deck` | Select starter deck |

**Collections** (`/api/collections/`)
| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/collections/me` | Get user's card collection |
| GET | `/collections/me/cards/{card_id}` | Get specific card quantity |

**Decks** (`/api/decks/`)
| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/decks` | List user's decks |
| POST | `/decks` | Create new deck |
| GET | `/decks/{id}` | Get deck by ID |
| PUT | `/decks/{id}` | Update deck |
| DELETE | `/decks/{id}` | Delete deck |
| POST | `/decks/validate` | Validate deck without saving |

**Games** (`/api/games/`)
| Method | Endpoint | Description |
|--------|----------|-------------|
| POST | `/games` | Create new game |
| GET | `/games/{id}` | Get game info |
| GET | `/games/me/active` | List user's active games |
| POST | `/games/{id}/resign` | Resign from game (HTTP fallback) |

### WebSocket Events (Socket.IO)

**Namespace:** `/game`

**Client → Server:**
| Event | Payload | Description |
|-------|---------|-------------|
| `game:join` | `{ game_id }` | Join/rejoin a game room |
| `game:action` | `{ action_type, ...data }` | Execute game action |
| `game:resign` | `{ game_id }` | Resign from game |
| `game:spectate` | `{ game_id }` | Join as spectator |
| `game:leave_spectate` | `{ game_id }` | Leave spectator mode |

**Server → Client:**
| Event | Payload | Description |
|-------|---------|-------------|
| `game:state` | `GameState` | Full game state (visibility filtered) |
| `game:action_result` | `ActionResult` | Result of player action |
| `game:error` | `{ message, code }` | Error notification |
| `game:turn_timeout_warning` | `{ remaining_seconds }` | Turn timer warning |
| `game:game_over` | `{ winner, reason }` | Game ended |
| `game:opponent_connected` | `{ connected }` | Opponent connection status |
| `game:reconnected` | `{ game_id, state }` | Auto-reconnected to game |
| `game:spectator_count` | `{ count }` | Spectator count update |

### Key Backend Files

| File | Description |
|------|-------------|
| `backend/app/api/auth.py` | Auth endpoints implementation |
| `backend/app/api/users.py` | User endpoints implementation |
| `backend/app/api/games.py` | Game REST endpoints |
| `backend/app/schemas/` | Pydantic request/response schemas |
| `backend/app/schemas/ws_messages.py` | WebSocket message schemas |
| `backend/app/socketio/game_namespace.py` | WebSocket event handlers |

### Type Definitions to Mirror

When creating frontend types, reference these backend schemas:
- `backend/app/schemas/user.py` → `UserResponse`, `UserUpdate`
- `backend/app/schemas/deck.py` → `DeckResponse`, `DeckCreate`, `DeckUpdate`
- `backend/app/schemas/game.py` → `GameCreateRequest`, `GameResponse`
- `backend/app/schemas/ws_messages.py` → All WebSocket message types

---

## See Also

- `PROJECT_PLAN_FRONTEND.json` - Phase plan and tasks
- `../backend/CLAUDE.md` - Backend guidelines
- `../backend/app/schemas/` - API schema definitions
- `../backend/app/socketio/README.md` - WebSocket documentation
- `../CLAUDE.md` - Project-wide guidelines
