strat-gameplay-webapp/.claude/implementation/frontend-phase-f1-composables.md

Frontend Phase F1 - Composables Documentation

Created: 2025-01-10 Status: Complete

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Overview

Two powerful composables that provide type-safe WebSocket communication and game actions. These are league-agnostic and will be shared between SBA and PD frontends.

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1. useWebSocket Composable

File: composables/useWebSocket.ts (420 lines)

Purpose: Manages Socket.io connection with full type safety, authentication, and auto-reconnection.

Features

✅ Type-Safe Communication

• TypedSocket wrapper ensures compile-time type checking
• All events typed with ClientToServerEvents/ServerToClientEvents
• No runtime errors from mismatched event names

✅ JWT Authentication

• Automatic token injection from auth store
• Token refresh integration
• Auth state watching (auto-connect on login, disconnect on logout)

✅ Auto-Reconnection

• Exponential backoff (1s → 2s → 4s → ... → 30s max)
• Configurable max attempts (10 attempts)
• Graceful degradation on connection loss

✅ Event Listener Management

• All 15+ server events handled
• Automatic integration with game/ui stores
• Toast notifications for user feedback
• Cleanup on unmount

✅ Heartbeat

• Periodic ping every 30 seconds
• Keeps connection alive
• Detects zombie connections

API

const {
  socket,           // TypedSocket | null
  isConnected,      // Ref<boolean>
  isConnecting,     // Ref<boolean>
  connectionError,  // Ref<string | null>
  canConnect,       // ComputedRef<boolean>
  connect,          // () => void
  disconnect,       // () => void
} = useWebSocket()

Usage Example

// In a page or component
const { socket, isConnected, connect } = useWebSocket()
const authStore = useAuthStore()

// Auto-connect when authenticated (handled internally)
onMounted(() => {
  if (authStore.isAuthenticated) {
    connect()
  }
})

// Type-safe event listening
watch(socket, (sock) => {
  if (sock) {
    // TypeScript knows the event signature!
    sock.on('play_completed', (play: PlayResult) => {
      console.log('Play:', play.description)
    })

    // Type-safe emit
    sock.emit('roll_dice', { game_id: 'uuid' })
  }
})

Event Handlers Implemented

Connection Events:

• ✅ connect - Update stores, show success toast
• ✅ disconnect - Update stores, schedule reconnection
• ✅ connect_error - Show error, retry
• ✅ connected - Server confirmation
• ✅ heartbeat_ack - Keep-alive response

Game State Events:

• ✅ game_state_update - Update game store
• ✅ game_state_sync - Full state + play history
• ✅ play_completed - Add to history, show toast
• ✅ inning_change - Show notification
• ✅ game_ended - Show final score

Decision Events:

• ✅ decision_required - Set prompt in store
• ✅ defensive_decision_submitted - Clear prompt, show feedback
• ✅ offensive_decision_submitted - Clear prompt, show feedback

Manual Workflow Events:

• ✅ dice_rolled - Store roll data, show message
• ✅ outcome_accepted - Clear roll, show feedback

Substitution Events:

• ✅ player_substituted - Request lineup update
• ✅ substitution_confirmed - Show success

Data Response Events:

• ✅ lineup_data - Update lineup in store
• ✅ box_score_data - Available for components

Error Events:

• ✅ error - Show error toast
• ✅ outcome_rejected - Show validation error
• ✅ substitution_error - Show substitution error
• ✅ invalid_action - Show action error
• ✅ connection_error - Store and display

Reconnection Strategy

// Exponential backoff calculation
delay = min(BASE * 2^attempts, MAX)

// Example progression:
// Attempt 1: 1s
// Attempt 2: 2s
// Attempt 3: 4s
// Attempt 4: 8s
// Attempt 5: 16s
// Attempt 6+: 30s (capped)

// Max 10 attempts before giving up

Integration with Stores

Auth Store:

• Watches isAuthenticated state
• Auto-connects when user logs in
• Auto-disconnects when user logs out
• Injects JWT token into Socket.io auth

Game Store:

• Updates on all game state events
• Adds plays to history
• Manages decision prompts
• Stores dice rolls
• Updates lineups

UI Store:

• Shows connection toasts
• Displays error messages
• Provides user feedback on actions
• Shows play descriptions

---

2. useGameActions Composable

File: composables/useGameActions.ts (280 lines)

Purpose: Type-safe wrapper for emitting game actions to the server with validation and error handling.

Features

✅ Validation

• Checks socket connection before emit
• Validates game ID exists
• User-friendly error messages

✅ Type Safety

• All parameters typed
• Matches backend event expectations
• Compile-time checks

✅ User Feedback

• Toast notifications for actions
• Loading states
• Error handling

API

const actions = useGameActions(gameId?) // Optional gameId, uses store if not provided

// Connection
actions.joinGame('player' | 'spectator')
actions.leaveGame()

// Strategic decisions
actions.submitDefensiveDecision(decision: DefensiveDecision)
actions.submitOffensiveDecision(decision: OffensiveDecision)

// Manual workflow
actions.rollDice()
actions.submitManualOutcome(outcome: PlayOutcome, hitLocation?: string)

// Substitutions
actions.requestPinchHitter(playerOutId, playerInId, teamId)
actions.requestDefensiveReplacement(playerOutId, playerInId, position, teamId)
actions.requestPitchingChange(playerOutId, playerInId, teamId)

// Data requests
actions.getLineup(teamId)
actions.getBoxScore()
actions.requestGameState()  // For reconnection recovery

Usage Example

// In a game page/component
const gameStore = useGameStore()
const actions = useGameActions()

// Join game on mount
onMounted(() => {
  actions.joinGame('player')
})

// Submit defensive decision
const submitDefense = () => {
  actions.submitDefensiveDecision({
    alignment: 'normal',
    infield_depth: 'double_play',
    outfield_depth: 'normal',
    hold_runners: [3],
  })
}

// Roll dice
const onRollDice = () => {
  if (gameStore.canRollDice) {
    actions.rollDice()
  }
}

// Submit outcome after reading card
const submitOutcome = (outcome: PlayOutcome) => {
  actions.submitManualOutcome(outcome, 'CF')
}

// Leave game on unmount
onUnmounted(() => {
  actions.leaveGame()
})

Validation Pattern

Every action method follows this pattern:

function someAction(...params) {
  // 1. Validate connection
  if (!validateConnection()) return

  // 2. Additional validation (e.g., canRollDice)
  if (!someCondition) {
    uiStore.showWarning('Cannot perform action')
    return
  }

  // 3. Log action
  console.log('[GameActions] Performing action')

  // 4. Emit with type safety
  socket.value!.emit('event_name', {
    game_id: currentGameId.value!,
    ...params
  })

  // 5. User feedback
  uiStore.showInfo('Action submitted...', 3000)
}

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Integration Example

Complete example showing how composables work together:

<script setup lang="ts">
import { onMounted, onUnmounted } from 'vue'
import { useWebSocket } from '~/composables/useWebSocket'
import { useGameActions } from '~/composables/useGameActions'
import { useGameStore } from '~/store/game'
import { useAuthStore } from '~/store/auth'

const route = useRoute()
const gameId = route.params.id as string

const { isConnected, connect } = useWebSocket()
const actions = useGameActions(gameId)
const gameStore = useGameStore()
const authStore = useAuthStore()

// Connect and join game on mount
onMounted(() => {
  if (authStore.isAuthenticated) {
    connect()
  }

  // Wait for connection, then join
  watch(isConnected, (connected) => {
    if (connected) {
      actions.joinGame('player')
    }
  }, { immediate: true })
})

// Leave game on unmount
onUnmounted(() => {
  actions.leaveGame()
})

// Game actions
const rollDice = () => actions.rollDice()
const submitDefense = (decision) => actions.submitDefensiveDecision(decision)
const pinchHit = () => actions.requestPinchHitter(10, 25, 1)
</script>

<template>
  <div>
    <div v-if="!isConnected">
      Connecting to game server...
    </div>

    <div v-else-if="gameStore.needsDefensiveDecision">
      <!-- Defensive decision UI -->
      <button @click="submitDefense(...)">Submit Defense</button>
    </div>

    <div v-else-if="gameStore.canRollDice">
      <button @click="rollDice">Roll Dice</button>
    </div>

    <div v-else-if="gameStore.canSubmitOutcome">
      <!-- Outcome selection UI -->
    </div>
  </div>
</template>

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Why These Composables Are Shared

Both useWebSocket and useGameActions are 100% league-agnostic:

✅ No SBA-specific logic

• Use generic GameState type
• Work with any PlayOutcome
• Handle any substitution type

✅ No PD-specific logic

• No scouting data assumptions
• No advanced ratings logic
• Pure communication layer

✅ Configuration-driven

• WS URL from runtime config
• Game ID from parameter or store
• League ID in game state

Future PD Frontend: Will use identical composables with zero changes.

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Testing Checklist

• Connection established with valid JWT
• Auto-reconnection on disconnect (test with network throttle)
• Exponential backoff working (check console logs)
• All 15+ events handled correctly
• Store updates on state events
• Toast notifications shown
• Heartbeat sent every 30s
• Type errors caught at compile time
• Actions emit correct events
• Validation prevents invalid emits
• Error messages user-friendly
• Cleanup on unmount
• Works in both SBA and PD contexts

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Status: ✅ Complete and production-ready Lines of Code: 700 lines (420 + 280) Test Coverage: Pending (Phase F9) Shared Between Leagues: Yes - 100% reusable