feat: AI coach functions

src/ai/coach.ts

@@ -0,0 +1,69 @@
+import type { Database } from 'better-sqlite3';
+import { createAiClient } from './client';
+import { buildContext } from './context';
+import { progressPrompt, nextStepPrompt, reschedulePrompt, setupPrompt } from './prompts';
+import { parseScheduleJson, type ScheduleProposal } from './parser';
+import { getSetting } from '../db/settings';
+import { config } from '../config';
+
+function getModel(db: Database): string {
+  return getSetting(db, 'model') ?? config.defaultModel;
+}
+
+async function chat(
+  db: Database,
+  system: string,
+  user: string,
+  jsonMode = false
+): Promise<string> {
+  const client = createAiClient();
+  const model = getModel(db);
+  const response = await client.chat.completions.create({
+    model,
+    messages: [
+      { role: 'system', content: system },
+      { role: 'user', content: user },
+    ],
+    ...(jsonMode ? { response_format: { type: 'json_object' } } : {}),
+  });
+  return response.choices[0]?.message.content ?? '';
+}
+
+export async function getProgressAnalysis(db: Database, today: string): Promise<string> {
+  const ctx = buildContext(db, today);
+  const { system, user } = progressPrompt(ctx);
+  return chat(db, system, user);
+}
+
+export async function getNextStep(db: Database, today: string): Promise<string> {
+  const ctx = buildContext(db, today);
+  const { system, user } = nextStepPrompt(ctx);
+  return chat(db, system, user);
+}
+
+export async function generateSchedule(
+  db: Database, today: string, note: string | null
+): Promise<ScheduleProposal[]> {
+  const ctx = buildContext(db, today);
+  const { system, user } = reschedulePrompt(ctx, note);
+  const raw = await chat(db, system, user);
+  return parseScheduleJson(raw);
+}
+
+export async function generateSetupSchedule(
+  db: Database,
+  today: string,
+  currentLevel: string,
+  availability: string,
+  goal: string
+): Promise<ScheduleProposal[]> {
+  const { system, user } = setupPrompt(currentLevel, availability, goal);
+  const raw = await chat(db, system, user);
+  return parseScheduleJson(raw);
+}
+
+export async function freeChat(db: Database, today: string, message: string): Promise<string> {
+  const ctx = buildContext(db, today);
+  const { system } = progressPrompt(ctx);
+  return chat(db, system, message);
+}