refactor(stage-4): partition monolithic main.py into modular APIRouters

app/routers/lessons.py

@@ -0,0 +1,193 @@
+from typing import Optional, List, Dict, Any
+from fastapi import APIRouter, Depends, HTTPException
+from pydantic import BaseModel
+
+from app.auth import require_user
+from app.database import get_db
+from app.lessons import (
+    get_user_presets,
+    save_user_preset,
+    delete_user_preset,
+    get_grammar_recommendations,
+    get_curated_articles,
+    record_lesson_session,
+    get_lesson_history,
+)
+from app.ai import generate_lesson_ai_debrief
+
+router = APIRouter(tags=["Lessons"])
+
+
+class SavePresetRequest(BaseModel):
+    name: str
+    steps: List[Dict[str, Any]]
+    icon: Optional[str] = "🚀"
+    description: Optional[str] = ""
+    estimated_min: Optional[int] = 15
+
+
+class LessonDebriefRequest(BaseModel):
+    preset_name: str
+    duration_seconds: int
+    total_score: int
+    steps: List[Dict[str, Any]]
+    errors: List[Dict[str, Any]]
+
+
+@router.get("/api/lessons/presets")
+async def api_lessons_get_presets(user: dict = Depends(require_user)):
+    """
+    Returns available lesson presets (defaults + user-custom).
+    """
+    with get_db() as conn:
+        presets = get_user_presets(conn, user["id"])
+        return {"presets": presets}
+
+
+@router.post("/api/lessons/presets")
+async def api_lessons_save_preset(
+    req: SavePresetRequest,
+    user: dict = Depends(require_user),
+):
+    """
+    Saves a custom user lesson configuration preset.
+    """
+    if not req.name.strip():
+        raise HTTPException(status_code=400, detail="Название шаблона не может быть пустым")
+    with get_db() as conn:
+        saved = save_user_preset(
+            conn,
+            user_id=user["id"],
+            name=req.name,
+            steps=req.steps,
+            icon=req.icon or "🚀",
+            description=req.description or "",
+            estimated_min=req.estimated_min or 15,
+        )
+        return {"status": "ok", "preset": saved}
+
+
+@router.delete("/api/lessons/presets/{preset_id}")
+async def api_lessons_delete_preset(
+    preset_id: int,
+    user: dict = Depends(require_user),
+):
+    """
+    Deletes a custom user lesson preset.
+    """
+    with get_db() as conn:
+        deleted = delete_user_preset(conn, user["id"], preset_id)
+        if not deleted:
+            raise HTTPException(status_code=404, detail="Пользовательский шаблон не найден")
+        return {"status": "ok", "deleted": True}
+
+
+@router.get("/api/lessons/grammar-recommendations")
+async def api_lessons_grammar_recommendations(user: dict = Depends(require_user)):
+    """
+    Calculates intelligent grammar suggestions: weakest topic, last studied topic,
+    next in syllabus, and full units list.
+    """
+    with get_db() as conn:
+        recs = get_grammar_recommendations(conn, user["id"])
+        return recs
+
+
+@router.get("/api/lessons/articles")
+async def api_lessons_articles(
+    topic: Optional[str] = None,
+    user: dict = Depends(require_user),
+):
+    """
+    Returns curated high-yield reading articles/facts for the lesson reading block.
+    """
+    articles = get_curated_articles(topic=topic)
+    return {"articles": articles}
+
+
+@router.post("/api/lessons/debrief")
+async def api_lessons_debrief(
+    req: LessonDebriefRequest,
+    user: dict = Depends(require_user),
+):
+    """
+    Generates a pedagogic AI debrief for the completed lesson session,
+    enriches with historical error context, and records the session.
+    """
+    # 1. Fetch user error history for pedagogical pattern detection
+    with get_db() as conn:
+        chronic_rows = conn.execute(
+            """
+            SELECT v.term, count(*) as err_cnt
+            FROM srs_logs l
+            JOIN vocabulary_cards v ON v.id = l.card_id
+            WHERE l.user_id = ? AND l.rating = 1
+            GROUP BY v.term
+            HAVING err_cnt > 1
+            ORDER BY err_cnt DESC
+            LIMIT 10
+            """,
+            (user["id"],),
+        ).fetchall()
+        chronic_vocab = [r["term"] for r in chronic_rows]
+
+        prog_rows = conn.execute(
+            """
+            SELECT u.unit_num
+            FROM grammar_progress p
+            JOIN grammar_units u ON u.id = p.unit_id
+            WHERE p.user_id = ? AND p.score < 80
+            """,
+            (user["id"],),
+        ).fetchall()
+        past_grammar = [r["unit_num"] for r in prog_rows]
+
+    history_data = {
+        "chronic_vocab_errors": chronic_vocab,
+        "past_grammar_errors": past_grammar,
+    }
+
+    session_payload = {
+        "preset_name": req.preset_name,
+        "duration_seconds": req.duration_seconds,
+        "total_score": req.total_score,
+        "steps": req.steps,
+        "errors": req.errors,
+    }
+
+    # 2. Generate AI or deterministic debrief
+    ai_report = await generate_lesson_ai_debrief(session_payload, history_data)
+
+    # 3. Save completed session to SQLite
+    with get_db() as conn:
+        session_id = record_lesson_session(
+            conn=conn,
+            user_id=user["id"],
+            preset_name=req.preset_name,
+            duration_seconds=req.duration_seconds,
+            total_score=req.total_score,
+            grade=ai_report.get("grade", "A"),
+            steps_summary=req.steps,
+            errors_list=req.errors,
+            ai_report=ai_report,
+        )
+
+    return {
+        "session_id": session_id,
+        "ai_report": ai_report,
+        "total_score": req.total_score,
+        "grade": ai_report.get("grade", "A"),
+    }
+
+
+@router.get("/api/lessons/history")
+async def api_lessons_history(
+    limit: int = 15,
+    user: dict = Depends(require_user),
+):
+    """
+    Returns history of completed comprehensive lessons and overall learning metrics.
+    """
+    with get_db() as conn:
+        data = get_lesson_history(conn, user["id"], limit=limit)
+        return data