#!/usr/bin/env python3
"""
embed.py — Embed marine doc chunks with Gemini Embedding 2 (locked model).

Model: gemini-embedding-2-preview  (768-dim, L2-normalized, RETRIEVAL_DOCUMENT).
No substitutes. Reranker is handled separately in search.py (Google Vertex Rank API).

Key resolution order:
  1. env GOOGLE_API_KEY
  2. env GEMINI_API_KEY
  3. vertex_api_key=... in /Users/dmpantiu/cmip6/cmip6_gpt/.env

Modes:
  realtime  — streaming API, resumable (default)
  batch     — submit Batch API job (50% cost), then `status` / `download`
  status    --resume <job>
  download  --resume <job>

Usage:
  python embed.py --mode realtime
  python embed.py --mode realtime --limit 20      # smoke test
"""
import argparse
import json
import math
import os
import sys
import time
from pathlib import Path

import numpy as np

import net_ipv4  # noqa: F401  — force IPv4 egress (VPN), must precede genai client

ROOT = Path(__file__).resolve().parent
OUT = ROOT / "out"
IN_JSONL = OUT / "chunks.jsonl"
OUT_JSONL = OUT / "chunks_embedded.jsonl"
BATCH_INPUT = OUT / "batch_embed_input.jsonl"

MODEL = "gemini-embedding-2-preview"
TASK_TYPE = "RETRIEVAL_DOCUMENT"
OUTPUT_DIM = 768
# AQ express key on gemini-embedding-2-preview is quota-capped at ~5 req/min.
# Big batches (100 contents/req) + ~13s spacing keep us under the cap.
RT_BATCH = 100
RT_SLEEP = 13.0


def resolve_key() -> str:
    for var in ("GOOGLE_API_KEY", "GEMINI_API_KEY"):
        if os.environ.get(var):
            return os.environ[var]
    # new key lives in copernicus_mcp/.env (field may be misspelled 'veretex_api_key')
    for env in (Path("/Users/dmpantiu/copernicus_mcp/.env"),
                Path("/Users/dmpantiu/cmip6/cmip6_gpt/.env")):
        if env.exists():
            for line in env.read_text().splitlines():
                line = line.strip()
                if "api_key" in line.lower() and "=" in line and not line.startswith("#"):
                    return line.split("=", 1)[1].strip().strip('"').strip("'")
    raise SystemExit("No Gemini API key found (GOOGLE_API_KEY / vertex_api_key).")


def get_client():
    from google import genai
    return genai.Client(api_key=resolve_key())


def l2(vec):
    a = np.array(vec, dtype=np.float32)
    n = np.linalg.norm(a)
    return (a / n).tolist() if n > 0 else a.tolist()


def load_chunks(limit=None):
    rows = []
    with open(IN_JSONL) as f:
        for i, line in enumerate(f):
            if limit and i >= limit:
                break
            rows.append(json.loads(line))
    return rows


def embed_realtime(chunks):
    from google.genai import types
    client = get_client()
    done = set()
    if OUT_JSONL.exists():
        for line in open(OUT_JSONL):
            try:
                done.add(json.loads(line)["chunk_id"])
            except Exception:
                pass
        print(f"resume: {len(done)} already embedded")
    todo = [c for c in chunks if c["chunk_id"] not in done]
    print(f"to embed: {len(todo)} / {len(chunks)}")
    n = 0
    with open(OUT_JSONL, "a", encoding="utf-8") as fout:
        for b in range(0, len(todo), RT_BATCH):
            batch = todo[b:b + RT_BATCH]
            texts = [c["text_with_prefix"] for c in batch]
            for attempt in range(6):
                try:
                    # genai 1.64 can raise "client has been closed" — recreate on retry
                    if attempt > 0:
                        client = get_client()
                    r = client.models.embed_content(
                        model=MODEL, contents=texts,
                        config=types.EmbedContentConfig(
                            task_type=TASK_TYPE, output_dimensionality=OUTPUT_DIM),
                    )
                    for c, e in zip(batch, r.embeddings):
                        c["embedding"] = l2(e.values)
                        fout.write(json.dumps(c, ensure_ascii=False) + "\n")
                        n += 1
                    fout.flush()
                    break
                except Exception as e:
                    es = str(e)
                    if "IP address restriction" in es:
                        raise SystemExit(
                            "BLOCKED: Gemini key has IP restriction. Whitelist this host's "
                            "IP in Google Cloud Console (API key settings) and re-run.")
                    if any(k in es for k in ("429", "RESOURCE_EXHAUSTED", "Quota exceeded")):
                        wait = 35            # ~5 RPM quota — wait out the minute window
                    elif "client has been closed" in es:
                        wait = 2             # flaky genai transport; client recreated on retry
                    else:
                        wait = min(8 * (2 ** attempt), 60)
                    print(f"  retry {attempt+1}/8 in {wait}s: {repr(e)[:120]}", file=sys.stderr)
                    time.sleep(wait)
            else:
                print(f"  FATAL skip {len(batch)}", file=sys.stderr)
            if n % 400 == 0:
                print(f"  [{n}/{len(todo)}]")
            time.sleep(RT_SLEEP)
    print(f"DONE: {n} embedded → {OUT_JSONL}")


JOB_FILE = OUT / "batch_job.txt"


def prepare_batch(chunks):
    # Correct batch schema: request.content (singular) + flat task_type/output_dimensionality.
    with open(BATCH_INPUT, "w", encoding="utf-8") as f:
        for c in chunks:
            f.write(json.dumps({
                "key": c["chunk_id"],
                "request": {
                    "content": {"parts": [{"text": c["text_with_prefix"]}]},
                    "task_type": TASK_TYPE,
                    "output_dimensionality": OUTPUT_DIM,
                },
            }, ensure_ascii=False) + "\n")
    print(f"batch input: {BATCH_INPUT} ({BATCH_INPUT.stat().st_size/1e6:.1f} MB, {len(chunks)} reqs)")


def submit_batch():
    client = get_client()
    up = client.files.upload(file=str(BATCH_INPUT),
                             config={"display_name": "marine_embed_input", "mime_type": "jsonl"})
    job = client.batches.create_embeddings(
        model=MODEL, src={"file_name": up.name},
        config={"display_name": "marine_docs_embeddings"})
    JOB_FILE.write_text(job.name)
    print(f"job: {job.name}  state: {job.state}  (saved to {JOB_FILE})")
    return job.name


def _extract_values(resp: dict):
    """Pull the embedding vector out of a batch result line, shape-tolerant."""
    for path in (("response", "embeddings"), ("response", "embedding"), ("embeddings",), ("embedding",)):
        node = resp
        ok = True
        for k in path:
            if isinstance(node, dict) and k in node:
                node = node[k]
            else:
                ok = False
                break
        if not ok:
            continue
        if isinstance(node, list) and node and isinstance(node[0], dict) and "values" in node[0]:
            return node[0]["values"]
        if isinstance(node, dict) and "values" in node:
            return node["values"]
    return None


def poll_and_download(chunks, wait=True):
    client = get_client()
    name = JOB_FILE.read_text().strip()
    while True:
        job = client.batches.get(name=name)
        state = str(job.state)
        print(f"  job {name}: {state}")
        if "SUCCEEDED" in state or "FAILED" in state or "CANCELLED" in state or "EXPIRED" in state:
            break
        if not wait:
            return False
        time.sleep(30)
    if "SUCCEEDED" not in state:
        print(f"job not successful: {state}")
        return False

    by_key = {c["chunk_id"]: c for c in chunks}
    dest = getattr(job, "dest", None)
    fn = getattr(dest, "file_name", None) if dest else None
    lines = []
    if fn:
        lines = client.files.download(file=fn).decode("utf-8").strip().split("\n")
    elif dest and getattr(dest, "inlined_responses", None):
        lines = [json.dumps(r) for r in dest.inlined_responses]
    n = 0
    with open(OUT_JSONL, "w", encoding="utf-8") as fout:
        for line in lines:
            if not line.strip():
                continue
            r = json.loads(line)
            k = r.get("key") or r.get("custom_metadata") or r.get("custom_id")
            vals = _extract_values(r)
            if k in by_key and vals:
                c = dict(by_key[k])
                c["embedding"] = l2(vals)
                fout.write(json.dumps(c, ensure_ascii=False) + "\n")
                n += 1
    print(f"DOWNLOADED: {n}/{len(chunks)} embeddings → {OUT_JSONL}")
    return n >= len(chunks) * 0.99


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--mode", choices=["realtime", "batch", "submit", "poll", "status", "download"],
                    default="realtime")
    ap.add_argument("--limit", type=int, default=None)
    ap.add_argument("--resume", type=str, default=None)
    a = ap.parse_args()

    chunks = load_chunks(a.limit)
    toks = sum(c["token_count"] for c in chunks)
    print(f"chunks={len(chunks):,} tokens={toks:,} "
          f"est realtime=${toks/1e6*0.25:.2f} batch=${toks/1e6*0.125:.2f}")

    if a.mode == "realtime":
        embed_realtime(chunks)
    elif a.mode in ("batch", "submit"):
        prepare_batch(chunks)
        submit_batch()
        if a.mode == "batch":
            poll_and_download(chunks, wait=True)
    elif a.mode == "poll":
        poll_and_download(chunks, wait=True)
    elif a.mode in ("status", "download"):
        client = get_client()
        name = a.resume or JOB_FILE.read_text().strip()
        job = client.batches.get(name=name)
        print(f"state: {job.state}")
        if a.mode == "download":
            poll_and_download(chunks, wait=False)


if __name__ == "__main__":
    main()