add Pattern Context.

src/context/Patterns.tsx

@@ -0,0 +1,157 @@
+import { invoke } from '@tauri-apps/api/core';
+import dayjs from 'dayjs';
+import { atom } from 'jotai';
+import { atomFamily } from 'jotai/utils';
+import { get, reduce } from 'lodash-es';
+import { v4 } from 'uuid';
+
+export enum FrequencyShifting {
+  /**
+   * Change frequency undergoes a linear transformation from previous pulse to current one.
+   */
+  Linear,
+  /**
+   * Change frequency undergoes a quadratic transformation from previous pulse to current one.
+   */
+  Quadratic,
+  /**
+   * Change frequency undergoes a cubic transformation from previous pulse to current one.
+   */
+  Cubic,
+  /**
+   * Change frequency with quick fade in and fade out.
+   */
+  Ease,
+  /**
+   * Change frequency with spiking within range from previous pulse and current one.
+   */
+  Pulsating,
+  /**
+   * Based on frequency of previous pulse, take the twice of frequency of current pulse as the peak frequency. Follow the maximum frequency limitation.
+   */
+  Spiking,
+  /**
+   * Randomize frequency within range from previous frequency and current one.
+   */
+  Randomize,
+  /**
+   * Randomize frequency within minium and maximum frequency.
+   */
+  Maniac,
+  /**
+   * Synchronize changes of frequency with pulse width changes.
+   */
+  Synchronized,
+}
+
+export interface ControlPoint {
+  x: number;
+  y: number;
+}
+
+export class Pulse {
+  order: number;
+  id: number;
+  duration: number;
+  width: number;
+  maniac: boolean;
+  frequency: number;
+  frequencyShifting: FrequencyShifting;
+  controlPoint1: ControlPoint;
+  controlPoint2: ControlPoint;
+
+  constructor(order: number, width: number, frequency: number) {
+    this.id = v4();
+    this.order = order;
+    this.duration = 25;
+    this.width = width;
+    this.maniac = false;
+    this.frequency = frequency;
+    this.frequencyShifting = FrequencyShifting.Linear;
+    this.controlPoint1 = { x: 0, y: 0 };
+    this.controlPoint2 = { x: 0, y: 0 };
+  }
+
+  equals(other: Pulse): boolean {
+    return this.id === other.id;
+  }
+}
+
+export class Pattern {
+  id: string;
+  name: string;
+  createdAt: number;
+  lastModifiedAt: number | null;
+  smoothRepeat: boolean;
+  pulses: Pulse[];
+
+  constructor() {
+    this.id = v4();
+    this.name = '';
+    this.createdAt = dayjs().valueOf();
+    this.lastModifiedAt = null;
+    this.smoothRepeat = true;
+    this.Pulses = [];
+  }
+}
+
+export function createNewPulse(pattern: Pattern): Pulse {
+  const maxOrder = reduce(pattern.pulses, (former, pulse) => Math.max(former, pulse.order), 0);
+  if (pattern.smoothRepeat) {
+    return new Pulse(
+      maxOrder + 1,
+      get(pattern.pulses, '[0].width', 0),
+      get(pattern.pulses, '[0].frequency', 1),
+    );
+  } else {
+    return new Pulse(
+      maxOrder + 1,
+      get(pattern.pulses, '[-1].width', 0),
+      get(pattern.pulses, '[-1].frequency', 1),
+    );
+  }
+}
+
+export function totalDuration(pattern: Pattern): number {
+  return reduce(
+    pattern.smoothRepeat ? pattern.pulses : pattern.pulses.slice(0, -1),
+    (former, pulse) => former + pulse.duration,
+    0,
+  );
+}
+
+export const PatternsAtom = atomFamily((keyword: string) =>
+  atom(async () => {
+    try {
+      const patterns = await invoke<Pattern[]>('list_patterns', { keyword });
+      return patterns;
+    } catch (e) {
+      console.error('[retreiving pattern list]', e);
+    }
+    return [];
+  }),
+);
+export const CurrentPatternAtom = atom<Pattern | null>(null);
+export const PulsesInCurrentPatternAtom = atom(
+  (get) => get(CurrentPatternAtom)?.pulses ?? [],
+  (get, set, pulse: Pulse) => {
+    const currentPulses = get(CurrentPatternAtom)?.pulses ?? [];
+    const newPulses = currentPulses.map((p) => (p.id === pulse.id ? pulse : p));
+    if (!newPulses.some((p) => p.id === pulse.id)) {
+      newPulses.push(pulse);
+    }
+    newPulses.sort((a, b) => a.order - b.order);
+    const currentPattern = get(CurrentPatternAtom);
+    if (currentPattern) {
+      set(CurrentPatternAtom, {
+        ...currentPattern,
+        pulses: newPulses,
+      });
+    }
+  },
+);
+export const CurrentPatternDuration = atom((get) => {
+  const currentPattern = get(CurrentPatternAtom);
+  if (!currentPattern) return 0;
+  return totalDuration(currentPattern);
+});