import os
import re
import json
import shutil
import asyncio
from pathlib import Path

# Cache HF model downloads in persistent storage so cold starts skip re-downloading
os.environ.setdefault("HF_HOME", "/data/.cache")
from typing import Optional, List

import httpx
import spaces
import gradio as gr
from bs4 import BeautifulSoup
from fastapi import BackgroundTasks, Form, UploadFile, File, Request, HTTPException
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
from pydantic import BaseModel

from config import UPLOADS_DIR, DB_PATH
CONTENT_DIR = UPLOADS_DIR / "content"

from db import (
    init_db, save_capture, update_capture, get_captures, get_surfaceable,
    mark_surfaced, mark_done, get_all_embeddings, get_captures_by_ids,
    delete_capture, patch_capture, get_review_queue, record_review,
    search_captures, get_brief, get_brief_dates, get_brief_week, get_captures_by_intent,
    get_review_history, get_review_streak,
)
from lm import (
    process_text, process_link, process_image, embed, find_related,
    generate_recall_question, synthesize_answer, generate_extend,
    generate_feynman_questions, grade_feynman_answers, generate_learning_arc,
    generate_brief_synthesis, generate_weekly_synthesis,
)
from surface import pick


# ── ZeroGPU: @spaces.GPU must be at module level ──────────────────────────────

@spaces.GPU
def _warmup():
    pass


# ── Minimal Gradio demo (required for ZeroGPU launch) ─────────────────────────

with gr.Blocks() as demo:
    pass


# ── Run startup synchronously before server launch ────────────────────────────

UPLOADS_DIR.mkdir(parents=True, exist_ok=True)
CONTENT_DIR.mkdir(exist_ok=True)
init_db()

_force_reseed = bool(os.getenv("FORCE_RESEED"))
if _force_reseed and DB_PATH.exists():
    print("[startup] FORCE_RESEED=1 — deleting existing DB and reseeding")
    DB_PATH.unlink()
    init_db()

_gc = get_captures
if _force_reseed or len(_gc(limit=1)) == 0:
    try:
        import seed
        seed.run()
    except Exception as e:
        print(f"[seed] {e}")
else:
    try:
        import sqlite3 as _sqlite3
        all_embs = get_all_embeddings()
        for cid, emb_row in all_embs:
            related = find_related(emb_row, all_embs, exclude_id=cid)
            with _sqlite3.connect(DB_PATH) as _conn:
                _conn.execute(
                    "UPDATE captures SET related_ids=? WHERE id=?",
                    (json.dumps(related), cid)
                )
        print(f"[startup] related_ids backfill complete ({len(all_embs)} captures)")
    except Exception as e:
        print(f"[startup backfill] {e}")


# ── Launch Gradio (initializes ZeroGPU), get underlying FastAPI app ───────────

_, local_url, _ = demo.launch(
    server_port=7860,
    prevent_thread_lock=True,
    show_error=True,
    ssr_mode=False,  # Disable Node proxy so Python serves all routes directly
)
app = demo.app

# Gradio registers GET "/" for its own (empty) Blocks UI — remove it so our
# StaticFiles mount at "/" can serve the React index.html instead.
from fastapi.routing import APIRoute as _APIRoute
from starlette.routing import Route as _SRoute
app.router.routes = [
    r for r in app.router.routes
    if not (
        isinstance(r, (_APIRoute, _SRoute))
        and getattr(r, "path", None) == "/"
        and "GET" in (getattr(r, "methods", None) or set())
    )
]


# ── API routes ─────────────────────────────────────────────────────────────────

@app.get("/uploads/content/{capture_id}.txt")
async def serve_source_content(capture_id: int):
    path = CONTENT_DIR / f"{capture_id}.txt"
    if not path.exists():
        raise HTTPException(status_code=404)
    return FileResponse(path, media_type="text/plain; charset=utf-8")

@app.get("/uploads/{filename:path}")
async def serve_upload(filename: str):
    path = UPLOADS_DIR / filename
    if not path.exists():
        raise HTTPException(status_code=404)
    return FileResponse(path)

@app.post("/capture/text")
async def capture_text(background_tasks: BackgroundTasks, content: str = Form(...), your_take: str = Form("")):
    cid = save_capture("text", raw=content, your_take=your_take)
    background_tasks.add_task(_process, cid, "text", content=content, your_take=your_take)
    return {"id": cid, "status": "captured"}

@app.post("/capture/link")
async def capture_link(background_tasks: BackgroundTasks, url: str = Form(...), your_take: str = Form("")):
    cid = save_capture("link", raw=url, source_url=url, your_take=your_take)
    background_tasks.add_task(_process, cid, "link", url=url, your_take=your_take)
    return {"id": cid, "status": "captured"}

@app.post("/capture/image")
async def capture_image(
    background_tasks: BackgroundTasks,
    file: UploadFile = File(...),
    description: str = Form(""),
    your_take: str = Form(""),
):
    dest = UPLOADS_DIR / file.filename
    with open(dest, "wb") as f:
        shutil.copyfileobj(file.file, f)
    cid = save_capture("image", raw=description or None, file_path=str(dest), your_take=description or None)
    background_tasks.add_task(_process, cid, "image", file_path=str(dest), description=description, your_take=description)
    return {"id": cid, "status": "captured"}

@app.get("/captures")
async def list_captures(limit: int = 50, intent: Optional[str] = None):
    if intent:
        return get_captures_by_intent(intent, limit)
    return get_captures(limit)

@app.get("/captures/{capture_id}")
async def get_capture(capture_id: int):
    from db import get_capture_by_id
    c = get_capture_by_id(capture_id)
    if not c:
        raise HTTPException(status_code=404)
    return c


@app.get("/captures/{capture_id}/related")
async def related_captures(capture_id: int):
    import sqlite3
    with sqlite3.connect(DB_PATH) as conn:
        conn.row_factory = sqlite3.Row
        row = conn.execute("SELECT related_ids FROM captures WHERE id=?", (capture_id,)).fetchone()
        if not row:
            return []
        ids = json.loads(row["related_ids"] or "[]")
        if not ids:
            return []
        placeholders = ",".join("?" * len(ids))
        rows = conn.execute(f"SELECT * FROM captures WHERE id IN ({placeholders})", ids).fetchall()
        result = []
        for r in rows:
            d = dict(r)
            d["tags"] = json.loads(d["tags"] or "[]")
            d.pop("embedding", None)
            result.append(d)
        return result

@app.delete("/captures/{capture_id}")
async def delete_capture_endpoint(capture_id: int):
    delete_capture(capture_id)
    return {"status": "deleted"}

VALID_MOODS = {"focused", "curious", "restless", "tired", "inspired"}

@app.get("/surface")
async def surface(mode: str = None, n: int = 3, mood: str = None):
    mood = mood if mood in VALID_MOODS else None
    candidates = get_surfaceable(include_ephemeral=(mood == "bored"))
    items = pick(candidates, n=n, mode=mode, mood=mood)
    for item in items:
        related_ids = json.loads(item.get("related_ids") or "[]")
        item["related"] = get_captures_by_ids(related_ids)
        item.pop("embedding", None)
    return items

@app.post("/surface/{capture_id}/done")
async def surface_done(capture_id: int):
    mark_done(capture_id)
    return {"status": "done"}

@app.post("/surface/{capture_id}/skip")
async def surface_skip(capture_id: int):
    mark_surfaced(capture_id)
    return {"status": "skipped"}

@app.post("/events")
async def log_event(request: Request):
    data = await request.json()
    import sqlite3
    with sqlite3.connect(DB_PATH) as conn:
        conn.execute(
            "INSERT INTO events (capture_id, event, value, created_at) VALUES (?, ?, ?, datetime('now','localtime'))",
            (data.get("capture_id"), data.get("event"), str(data.get("value", "")))
        )
    return {"status": "ok"}

class PatchBody(BaseModel):
    intent: Optional[str] = None
    tags: Optional[List[str]] = None

@app.patch("/captures/{capture_id}")
async def patch_capture_endpoint(capture_id: int, body: PatchBody):
    patch_capture(capture_id, intent=body.intent, tags=body.tags)
    return {"status": "updated"}

@app.get("/review")
async def review_queue(limit: int = 10):
    return get_review_queue(limit)

@app.get("/review/history")
async def review_history(days: int = 7):
    return {"reviewed_dates": get_review_history(days), "streak": get_review_streak()}

class ReviewBody(BaseModel):
    rating: str

@app.post("/captures/{capture_id}/review")
async def post_review(capture_id: int, body: ReviewBody):
    if body.rating not in ("got_it", "again"):
        raise HTTPException(status_code=400, detail="rating must be 'got_it' or 'again'")
    record_review(capture_id, body.rating)
    return {"status": "recorded"}

@app.get("/search")
async def search(q: str, limit: int = 20):
    if not q.strip():
        return []
    loop = asyncio.get_event_loop()
    query_emb = await loop.run_in_executor(None, embed, q.strip())
    if query_emb:
        all_embs = get_all_embeddings()
        from lm import _cosine
        scored = sorted(
            [(cid, _cosine(query_emb, emb)) for cid, emb in all_embs],
            key=lambda x: x[1], reverse=True
        )
        top = [(cid, score) for cid, score in scored[:limit] if score > 0.3]
        if top:
            score_map = {cid: score for cid, score in top}
            captures = get_captures_by_ids([cid for cid, _ in top])
            for c in captures:
                c["score"] = round(score_map.get(c["id"], 0), 3)
            captures.sort(key=lambda c: c["score"], reverse=True)
            return captures
    return search_captures(q.strip(), limit)

class AskBody(BaseModel):
    query: str
    capture_ids: List[int]

class ExtendBody(BaseModel):
    query: str
    synthesis: str

@app.post("/ask/synthesize")
async def ask_synthesize(body: AskBody):
    if not body.query.strip() or not body.capture_ids:
        return {"synthesis": "", "tension": None}
    captures = get_captures_by_ids(body.capture_ids[:8])
    loop = asyncio.get_event_loop()
    result = await loop.run_in_executor(None, synthesize_answer, body.query.strip(), captures)
    tension = None
    text = result
    m = re.search(r'\[TENSION:\s*(.*?)\]', result, re.IGNORECASE | re.DOTALL)
    if m:
        tension = m.group(1).strip()
        text = result[:m.start()].strip()
    return {"synthesis": text, "tension": tension}

@app.post("/ask/extend")
async def ask_extend(body: ExtendBody):
    if not body.query.strip() or not body.synthesis.strip():
        return {"gap": "", "questions": []}
    loop = asyncio.get_event_loop()
    return await loop.run_in_executor(None, generate_extend, body.query.strip(), body.synthesis.strip())

class FeynmanBody(BaseModel):
    query: str
    capture_ids: List[int]

class FeynmanGradeBody(BaseModel):
    qa_pairs: List[dict]
    capture_ids: List[int]

class ArcBody(BaseModel):
    query: str
    capture_ids: List[int]

@app.post("/ask/feynman")
async def ask_feynman(body: FeynmanBody):
    captures = get_captures_by_ids(body.capture_ids[:8])
    loop = asyncio.get_event_loop()
    return {"questions": await loop.run_in_executor(None, generate_feynman_questions, body.query.strip(), captures)}

@app.post("/ask/feynman/grade")
async def ask_feynman_grade(body: FeynmanGradeBody):
    captures = get_captures_by_ids(body.capture_ids[:8])
    loop = asyncio.get_event_loop()
    return {"grades": await loop.run_in_executor(None, grade_feynman_answers, body.qa_pairs, captures)}

@app.post("/ask/arc")
async def ask_arc(body: ArcBody):
    captures = get_captures_by_ids(body.capture_ids[:15])
    loop = asyncio.get_event_loop()
    return {"periods": await loop.run_in_executor(None, generate_learning_arc, body.query.strip(), captures)}

@app.get("/brief/dates")
async def brief_dates():
    return get_brief_dates()

@app.get("/brief/week")
async def brief_week():
    return get_brief_week()

class WeeklySynthesisBody(BaseModel):
    daily_entries: List[dict]

@app.post("/brief/week/synthesize")
async def brief_week_synthesize(body: WeeklySynthesisBody):
    loop = asyncio.get_event_loop()
    return {"synthesis": await loop.run_in_executor(None, generate_weekly_synthesis, body.daily_entries)}

@app.get("/brief")
async def brief(limit: int = 50, date: Optional[str] = None):
    items = get_brief(limit, date=date)
    grouped: dict[str, list] = {}
    for item in items:
        grouped.setdefault(item.get("intent") or "other", []).append(item)
    return grouped

class BriefSynthesisBody(BaseModel):
    capture_ids: List[int]
    date_label: Optional[str] = None

@app.post("/brief/synthesize")
async def brief_synthesize(body: BriefSynthesisBody):
    captures = get_captures_by_ids(body.capture_ids[:20])
    loop = asyncio.get_event_loop()
    return {"synthesis": await loop.run_in_executor(None, generate_brief_synthesis, captures, body.date_label or "")}

@app.post("/admin/regenerate-questions")
async def regenerate_questions(background_tasks: BackgroundTasks):
    background_tasks.add_task(_regenerate_questions_bg)
    return {"status": "started"}

async def _regenerate_questions_bg():
    import sqlite3
    loop = asyncio.get_event_loop()
    with sqlite3.connect(DB_PATH) as conn:
        conn.row_factory = sqlite3.Row
        rows = conn.execute("SELECT id, summary, intent, claims FROM captures WHERE summary IS NOT NULL").fetchall()
    updated = 0
    for row in rows:
        try:
            claims = json.loads(row["claims"] or "[]")
            q = await loop.run_in_executor(None, generate_recall_question, row["summary"], row["intent"] or "", claims)
            with sqlite3.connect(DB_PATH) as conn:
                conn.execute("UPDATE captures SET recall_question=? WHERE id=?", (q, row["id"]))
            updated += 1
        except Exception as e:
            print(f"[regen-questions] id={row['id']} error: {e}")
    print(f"[regen-questions] done — updated {updated} captures")


# ── Background processing ──────────────────────────────────────────────────────

async def _process(cid: int, type: str, **kwargs):
    loop = asyncio.get_event_loop()
    your_take = kwargs.get("your_take", "")
    source_content_path = None
    try:
        if type == "text":
            content = kwargs["content"]
            path = CONTENT_DIR / f"{cid}.txt"
            path.write_text(content, encoding="utf-8")
            source_content_path = str(path)
            result = await loop.run_in_executor(None, process_text, content, your_take)
        elif type == "link":
            page_text, page_title = await _fetch_page(kwargs["url"])
            if page_text:
                path = CONTENT_DIR / f"{cid}.txt"
                path.write_text(page_text, encoding="utf-8")
                source_content_path = str(path)
            result = await loop.run_in_executor(None, process_link, kwargs["url"], page_text, your_take, page_title)
        elif type == "image":
            result = await loop.run_in_executor(None, process_image, kwargs["file_path"], kwargs.get("description", ""), your_take)
        else:
            return
        summary = result.get("summary") or ""
        if not summary:
            raise ValueError("LM returned empty summary")
        claims = result.get("claims") or []
        title = result.get("title") or ""
        intent = result.get("intent")
        embed_text = summary + (" " + claims[0] if claims else "")
        emb = await loop.run_in_executor(None, embed, embed_text)
        all_embs = get_all_embeddings()
        related = find_related(emb, all_embs, exclude_id=cid)
        recall_q = await loop.run_in_executor(None, generate_recall_question, summary, intent or "", claims)
        update_capture(cid, summary, result.get("tags", []), intent, emb, related, recall_q, claims, source_content_path, title)
    except Exception as e:
        print(f"[process error] cid={cid} {e}")
        import sqlite3
        try:
            with sqlite3.connect(DB_PATH) as conn:
                conn.execute(
                    "UPDATE captures SET summary=?, intent='ephemeral' WHERE id=? AND summary IS NULL",
                    ("⚠ Processing failed — delete and retry", cid)
                )
        except Exception:
            pass


async def _fetch_page(url: str) -> tuple[str, str]:
    try:
        async with httpx.AsyncClient(follow_redirects=True, timeout=10) as client:
            resp = await client.get(url, headers={"User-Agent": "Mozilla/5.0"})
            soup = BeautifulSoup(resp.text, "html.parser")
            page_title = (soup.title.string or "").strip() if soup.title else ""
            for tag in soup(["script", "style", "nav", "footer"]):
                tag.decompose()
            return soup.get_text(separator=" ", strip=True), page_title
    except Exception:
        return "", ""


# ── Static files (React build) — added after launch so Gradio routes take
#    precedence for /gradio_api/* while React handles everything else ───────────

app.mount("/", StaticFiles(directory="static", html=True), name="static")

# Keep main thread alive
demo.block_thread()