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1/* ARCHITECTURE §5: mesin keadaan pemotretan sebagai fungsi murni (`reduce`).
2   Tanpa kamera dan tanpa timer: uji unit menjalankan seluruh tabel transisi. */
3
4export const COUNTDOWN_FROM = 3
5export const COUNTDOWN_STEP_MS = 1000
6export const PAUSE_MS = 300
7export const FLASH_MS = 160
8
9export type CountdownValue = 3 | 2 | 1
10export type DeniedReason = "denied" | "unavailable"
11
12export type CapturePhase =
13  | "idle"
14  | "requesting"
15  | "denied"
16  | "ready"
17  | "holding"
18  | "countdown"
19  | "capturing"
20  | "pause"
21  | "complete"
22
23export interface CaptureState {
24  phase: CapturePhase
25  countdownValue: CountdownValue | null
26  /** Slot yang sedang diganti lewat retake; null berarti slot kosong pertama. */
27  targetSlot: number | null
28  deniedReason: DeniedReason | null
29  /** Kilat sekali per foto (DESIGN-SYSTEM §7); tampilannya ditentukan lapisan UI. */
30  flash: boolean
31}
32
33export type CaptureEvent =
34  | { type: "PERMISSION_REQUEST" }
35  | { type: "PERMISSION_GRANTED" }
36  | { type: "PERMISSION_DENIED"; reason: DeniedReason }
37  | { type: "SHOOT"; target?: number }
38  | { type: "HOLD_START" }
39  | { type: "HOLD_CANCEL" }
40  | { type: "HOLD_COMPLETE" }
41  | { type: "TICK" }
42  | { type: "SHOT_SAVED" }
43  | { type: "FLASH_DONE" }
44  | { type: "PAUSE_DONE"; allFilled: boolean }
45
46export const INITIAL_CAPTURE_STATE: CaptureState = {
47  phase: "idle",
48  countdownValue: null,
49  targetSlot: null,
50  deniedReason: null,
51  flash: false,
52}
53
54/* Fase yang mengunci kontrol: baki foto dan tombol jepret tidak bisa dipakai
55   selama izin diminta, hitung mundur, pengambilan, dan jeda. */
56const BUSY_PHASES: Record<CapturePhase, boolean> = {
57  idle: false,
58  requesting: true,
59  denied: false,
60  ready: false,
61  holding: false,
62  countdown: true,
63  capturing: true,
64  pause: true,
65  complete: false,
66}
67
68export function isBusy(phase: CapturePhase): boolean {
69  return BUSY_PHASES[phase]
70}
71
72/* Tombol jepret hanya hidup saat kamera siap. `complete` sengaja mati:
73   mengganti foto saat semua slot terisi hanya lewat baki (FR-07). */
74const SHOOTABLE_PHASES: Record<CapturePhase, boolean> = {
75  idle: false,
76  requesting: false,
77  denied: false,
78  ready: true,
79  holding: false,
80  countdown: false,
81  capturing: false,
82  pause: false,
83  complete: false,
84}
85
86export function canShoot(phase: CapturePhase): boolean {
87  return SHOOTABLE_PHASES[phase]
88}
89
90export function reduce(state: CaptureState, event: CaptureEvent): CaptureState {
91  switch (state.phase) {
92    case "idle":
93    case "denied":
94      if (event.type === "PERMISSION_REQUEST") {
95        return { ...state, phase: "requesting" }
96      }
97      return state
98
99    case "requesting":
100      if (event.type === "PERMISSION_GRANTED") {
101        return { ...state, phase: "ready", deniedReason: null }
102      }
103      if (event.type === "PERMISSION_DENIED") {
104        return { ...state, phase: "denied", deniedReason: event.reason }
105      }
106      return state
107
108    case "ready":
109      if (event.type === "SHOOT") {
110        return {
111          ...state,
112          phase: "countdown",
113          countdownValue: COUNTDOWN_FROM,
114          targetSlot: event.target ?? null,
115        }
116      }
117      if (event.type === "HOLD_START") {
118        return { ...state, phase: "holding" }
119      }
120      return state
121
122    case "holding":
123      if (event.type === "HOLD_CANCEL") {
124        return { ...state, phase: "ready" }
125      }
126      /* GS-02: tahanan penuh memulai hitung mundur. GS-05: tombol kamera dan
127         Spasi tetap memotret walau gesture sedang ditahan. */
128      if (event.type === "HOLD_COMPLETE" || event.type === "SHOOT") {
129        return {
130          ...state,
131          phase: "countdown",
132          countdownValue: COUNTDOWN_FROM,
133          targetSlot: null,
134        }
135      }
136      return state
137
138    case "countdown":
139      if (event.type !== "TICK" || state.countdownValue === null) {
140        return state
141      }
142      if (state.countdownValue === 1) {
143        return {
144          ...state,
145          phase: "capturing",
146          countdownValue: null,
147          flash: true,
148        }
149      }
150      return { ...state, countdownValue: (state.countdownValue - 1) as CountdownValue }
151
152    case "capturing":
153      if (event.type === "SHOT_SAVED") {
154        return { ...state, phase: "pause" }
155      }
156      if (event.type === "FLASH_DONE") {
157        return { ...state, flash: false }
158      }
159      return state
160
161    case "pause":
162      if (event.type === "PAUSE_DONE") {
163        return {
164          ...state,
165          phase: event.allFilled ? "complete" : "ready",
166          targetSlot: null,
167        }
168      }
169      if (event.type === "FLASH_DONE") {
170        return { ...state, flash: false }
171      }
172      return state
173
174    case "complete":
175      /* Retake hanya lewat slot tertentu; tanpa target tidak ada yang diganti. */
176      if (event.type === "SHOOT" && event.target !== undefined) {
177        return {
178          ...state,
179          phase: "countdown",
180          countdownValue: COUNTDOWN_FROM,
181          targetSlot: event.target,
182        }
183      }
184      return state
185
186    default:
187      return state
188  }
189}
190