Add initial implementation

lib/markdown.js

@@ -0,0 +1,117 @@
+'use strict';
+
+const { EventEmitter } = require('node:events');
+const metautil = require('metautil');
+
+const notEmpty = (s) => s.length > 0;
+
+const cutString = (s, len = 1) => s.substring(len).trim();
+
+class Action {
+  constructor(text) {
+    const [name, data] = text.split(':');
+    this.name = name.trim();
+    this.unread = name.startsWith('(unread');
+    this.button = !name.startsWith('(');
+    const time = metautil.between(name, '(', ')');
+    this.time = metautil.duration(time);
+    this.target = data.trim();
+  }
+}
+
+class Scenario extends EventEmitter {
+  constructor(name, description, steps, menu) {
+    super();
+    this.name = cutString(name);
+    this.description = description;
+    this.steps = new Map(steps.map((step) => [step.name, step]));
+    const entry = steps.find((step) => step.entry);
+    this.entry = entry;
+    this.menu = menu;
+  }
+
+  start() {
+    const now = Date.now();
+    for (const step of this.steps.values()) {
+      if (!step.start) continue;
+      const timeout = step.start - now;
+      if (timeout > 0) {
+        setTimeout(() => {
+          const stepId = step.name;
+          this.emit('step', stepId);
+        }, timeout);
+      }
+    }
+  }
+}
+
+class Step {
+  constructor(name) {
+    this.name = name;
+    this.start = undefined;
+    this.entry = false;
+    if (name.includes('(')) {
+      const [title, start] = name.split('(');
+      this.name = title.trim();
+      const date = start.substring(0, start.length - 1);
+      if (date === 'immediate') {
+        this.entry = true;
+      } else {
+        const start = Date.parse(date.trim());
+        if (!isNaN(start)) this.start = start;
+      }
+    }
+    this.body = [];
+    this.actions = new Map();
+    this.buttons = [];
+  }
+}
+
+const ACTION = '+ ';
+
+const parseLine = (line) => {
+  const str = line.trim();
+  if (str.startsWith(ACTION)) {
+    return { type: 'action', text: cutString(str) };
+  } else {
+    return { type: 'message', text: str };
+  }
+};
+
+const parseStep = (src) => {
+  const pos = src.indexOf('\n');
+  const name = src.substring(0, pos);
+  const step = new Step(name);
+  const lines = cutString(src, pos).split('\n');
+  for (const line of lines) {
+    const { type, text } = parseLine(line);
+    if (type === 'action') {
+      const action = new Action(text);
+      step.actions.set(action.name, action);
+      if (action.button) {
+        step.buttons.push(action.name);
+      }
+    } else {
+      step.body.push(line);
+    }
+  }
+  return step;
+};
+
+const H2 = '## Step ';
+
+const parseMarkdown = (src) => {
+  const steps = src.split(H2).filter(notEmpty).map(parseStep);
+  const first = steps.shift();
+  const menu = [];
+  for (const action of first.actions.values()) {
+    const command = action.name;
+    const description = action.target;
+    menu.push({ command, description });
+  }
+  const descr = first.body.join('\n');
+  const scenario = new Scenario(first.name, descr, steps, menu);
+  return scenario;
+};
+
+module.exports = { parseMarkdown };