import hashlib
import json
import os
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, HTTPException
from fastapi.responses import StreamingResponse

import minio_tool
from app.core.security import admin_auth
from app.repositories import version_repository
from app.schemas.version import VersionIdRequest, VersionProtocolRequest
from app.services.common_service import is_executable_path
from app.services.signing_service import canonical_manifest_bytes, sign_manifest, sign_policy


TARGET_PLATFORM = os.getenv("TARGET_PLATFORM", "windows")
TARGET_ARCH = os.getenv("TARGET_ARCH", "x64")
SIGNING_KEY_ID = os.getenv("SIGNING_KEY_ID", "manifest-key-v1")

router = APIRouter(tags=["admin-version"])


@router.post("/admin/version/offline-package")
def admin_offline_package(body: VersionIdRequest, auth=Depends(admin_auth)):
    version_id = int(body.version_id or 0)
    ver, rows = version_repository.get_version_with_files(version_id)
    if not ver or not rows:
        raise HTTPException(status_code=404, detail="版本或版本文件不存在")
    files = [{"path": r["path"], "sha256": r["sha256"], "size": r["size"], "executable": is_executable_path(r["path"])} for r in rows]
    manifest = {
        "app_id": ver["app_id"],
        "version": ver["version"],
        "channel": ver["channel"],
        "platform": TARGET_PLATFORM,
        "arch": TARGET_ARCH,
        "manifest_seq": version_id,
        "created_at": ver["create_time"],
        "files": files,
    }
    manifest_text = canonical_manifest_bytes(manifest).decode()
    manifest_signature = sign_manifest(manifest)
    offset = 0
    entries = []
    for r in rows:
        entries.append({"path": r["path"], "offset": offset, "size": r["size"], "sha256": r["sha256"]})
        offset += int(r["size"] or 0)
    package = {
        "format": "MUPD0001",
        "app_id": ver["app_id"],
        "channel": ver["channel"],
        "version": ver["version"],
        "version_id": version_id,
        "created_at": datetime.now(timezone.utc).replace(microsecond=0).isoformat().replace("+00:00", "Z"),
        "manifest_sha256": hashlib.sha256(manifest_text.encode()).hexdigest(),
        "payload_size": offset,
        "files": entries,
        "signature_alg": "RSA-2048-SHA256",
        "key_id": SIGNING_KEY_ID,
    }
    package_text, package_signature = sign_policy(package)
    wrapper = json.dumps(
        {
            "package_text": package_text,
            "package_signature": package_signature,
            "manifest_text": manifest_text,
            "manifest_signature": manifest_signature,
        },
        ensure_ascii=False,
        separators=(",", ":"),
    ).encode()
    prefix = f"{ver['app_id']}/{ver['channel']}/{ver['version']}/files/"

    def stream():
        yield b"MUPD0001"
        yield len(wrapper).to_bytes(8, "little")
        yield wrapper
        for r in rows:
            yield from minio_tool.iter_file(prefix + r["path"])

    filename = f"{ver['app_id']}_{ver['channel']}_{ver['version']}.upd"
    return StreamingResponse(
        stream(),
        media_type="application/octet-stream",
        headers={"Content-Disposition": f'attachment; filename="{filename}"', "Content-Length": str(16 + len(wrapper) + offset)},
    )


@router.get("/admin/version/list")
def admin_get_version_list(app_id: str, auth=Depends(admin_auth)):
    return {"list": version_repository.list_versions(app_id)}


@router.post("/admin/version/set-protocol")
def admin_set_version_protocol(body: VersionProtocolRequest, auth=Depends(admin_auth)):
    version_id = int(body.version_id or 0)
    client_protocol = int(body.client_protocol or 0)
    if version_id < 1 or client_protocol < 1:
        raise HTTPException(status_code=400, detail="版本 ID 和客户端协议必须是正整数")
    updated = version_repository.set_version_protocol(version_id, client_protocol)
    if updated != 1:
        raise HTTPException(status_code=404, detail="版本不存在")
    return {"msg": "客户端协议已更新", "version_id": version_id, "client_protocol": client_protocol}


@router.post("/admin/version/set-latest")
def admin_set_latest(body: VersionIdRequest, auth=Depends(admin_auth)):
    vid = body.version_id
    result = version_repository.set_latest_version(vid)
    if result == "not_found":
        raise HTTPException(status_code=404, detail="版本不存在")
    return {"msg": "已切换为渠道最新版本"}


@router.post("/admin/version/delete")
def admin_delete_version(body: VersionIdRequest, auth=Depends(admin_auth)):
    vid = body.version_id
    v_info = version_repository.get_version_for_delete(vid)
    if not v_info:
        raise HTTPException(status_code=404, detail="版本不存在")
    aid, ch, ver = v_info["app_id"], v_info["channel"], v_info["version"]
    was_latest = bool(v_info["latest"])
    prefix = f"{aid}/{ch}/{ver}/files/"
    minio_tool.remove_prefix(prefix)
    promoted_version = version_repository.delete_version_and_promote(vid, aid, ch, was_latest)
    return {"msg": "版本、云端文件、数据库记录全部删除完成", "promoted_latest": promoted_version}