"""
OTA bucket enumerator.

The UBIA OTA buckets are Tencent COS:
  ubiaota-us-1312441409.cos.na-siliconvalley.myqcloud.com
  ubiaota-cn-1312441409.cos.ap-guangzhou.myqcloud.com

Anonymous LIST is denied, but individual objects can be public-read (we
confirmed this with the dev_add_doc/1159_video/* demo video). This module
guesses common firmware paths and reports any that return non-403/404.
"""

import json
import os
import urllib.request
import urllib.error
from datetime import datetime

from utils.log import log, C_INFO, C_SUCCESS, C_ERROR, C_IMPORTANT, C_TRAFFIC

BUCKETS = [
    "http://ubiaota-us-1312441409.cos.na-siliconvalley.myqcloud.com",
    "http://ubiaota-cn-1312441409.cos.ap-guangzhou.myqcloud.com",
]

# Path templates — {pid} = product id (1619 for our camera),
# {model} = model number (2604), {ver} = a version string
PATH_TEMPLATES = [
    "/dev_add_doc/{pid}/firmware.bin",
    "/dev_add_doc/{pid}/host.bin",
    "/dev_add_doc/{pid}/wifi.bin",
    "/dev_add_doc/{pid}/{model}.bin",
    "/dev_add_doc/{pid}/{ver}.bin",
    "/dev_add_doc/{pid}/{ver}/host.bin",
    "/dev_add_doc/{pid}/{ver}/firmware.bin",
    "/dev_add_doc/{pid}/{model}.{ver}.bin",
    "/dev_add_doc/{pid}_video/",
    "/firmware/{pid}/host.bin",
    "/firmware/{pid}/{ver}.bin",
    "/firmware/{model}/{ver}.bin",
    "/ota/{pid}/host.bin",
    "/ota/{pid}/{ver}.bin",
    "/ota/{model}/{ver}.bin",
    "/ota/{model}.{ver}.bin",
    "/{pid}/firmware.bin",
    "/{pid}/host.bin",
    "/{pid}/{ver}.bin",
    "/{model}/{ver}.bin",
    "/host/{model}/{ver}.bin",
    "/wifi/{model}/{ver}.bin",
    "/upgrade/{pid}/{ver}.bin",
    "/upgrade/{model}/{ver}.bin",
    "/dev_fw/{pid}/{ver}.bin",
    "/dev_fw/{model}/{ver}.bin",
    "/{model}.{ver}.bin",
    "/{ver}.bin",
]

# Versions to try — descending from current downward
VERSIONS_TO_TRY = [
    "2604.1.2.69",
    "2604.1.2.68",
    "2604.1.2.0",
    "2604.0.29.8",
    "2604.0.29.7",
    "2604.0.29.0",
    "2604.0.0.0",
    "2604",
]

PRODUCT_IDS = ["1619"]
MODELS = ["2604"]


def _head(url, timeout=8):
    req = urllib.request.Request(url, method="HEAD", headers={
        "User-Agent": "okhttp/4.9.1",
    })
    try:
        with urllib.request.urlopen(req, timeout=timeout) as r:
            return r.status, dict(r.headers), None
    except urllib.error.HTTPError as e:
        return e.code, dict(e.headers) if e.headers else {}, None
    except urllib.error.URLError as e:
        return None, {}, str(e.reason)
    except Exception as e:
        return None, {}, str(e)


def _build_paths():
    paths = set()
    for pid in PRODUCT_IDS:
        for model in MODELS:
            for ver in VERSIONS_TO_TRY:
                for tmpl in PATH_TEMPLATES:
                    paths.add(tmpl.format(pid=pid, model=model, ver=ver))
    return sorted(paths)


def probe(cfg=None):
    """
    Try every path×bucket combo. Report any HEAD that returns 200 or
    that has Content-Length > 0. Also report 403 (auth required —
    means the object exists), separately from 404.

    Returns:
        {
          "ok": bool,
          "found": [{"url","status","size","content_type"}],
          "exists_403": [...],
          "tried": int,
        }
    """
    paths = _build_paths()
    log(f"OTA-PROBE: trying {len(paths)} paths × {len(BUCKETS)} buckets = "
        f"{len(paths) * len(BUCKETS)} requests…", C_INFO)

    found = []
    exists_403 = []
    tried = 0
    for bucket in BUCKETS:
        for p in paths:
            url = bucket + p
            tried += 1
            status, headers, err = _head(url)
            if err:
                continue
            ct = headers.get("Content-Type", "?")
            cl = headers.get("Content-Length", "0")
            try:
                cl_i = int(cl)
            except (TypeError, ValueError):
                cl_i = 0
            if status == 200:
                log(f"  ✓ HIT 200 {url}  size={cl_i}  ct={ct}", C_IMPORTANT)
                found.append({"url": url, "status": 200,
                              "size": cl_i, "content_type": ct})
            elif status == 403:
                # Tencent COS returns 403 for "exists but no access" AND for
                # "doesn't exist" — but the response body differs. We log
                # them anyway since some might be real.
                exists_403.append({"url": url, "status": 403, "ct": ct})
            elif status and status not in (404,):
                log(f"  ? {status} {url}", C_TRAFFIC)

    log(f"OTA-PROBE: done. {len(found)} hits, {len(exists_403)} 403s, "
        f"{tried - len(found) - len(exists_403)} misses", C_SUCCESS)

    return {
        "ok": bool(found),
        "found": found,
        "exists_403_count": len(exists_403),
        "tried": tried,
    }