from __future__ import annotations

import hashlib
from datetime import datetime
from typing import Any

import psutil

from .database import get_db


def now_iso() -> str:
    return datetime.now().astimezone().isoformat(timespec="seconds")


def process_identity(name: str, exe_path: str | None, cmdline: str | None) -> str:
    raw = f"{name.lower()}|{(exe_path or cmdline or '').lower()}"
    return hashlib.sha256(raw.encode("utf-8", errors="ignore")).hexdigest()


def collect_services() -> list[dict[str, Any]]:
    if not hasattr(psutil, "win_service_iter"):
        return []

    services: list[dict[str, Any]] = []
    for service in psutil.win_service_iter():
        try:
            info = service.as_dict()
        except (psutil.Error, OSError):
            continue
        services.append(
            {
                "identity_key": info.get("name") or service.name(),
                "name": info.get("name") or service.name(),
                "display_name": info.get("display_name"),
                "status": info.get("status"),
                "start_type": info.get("start_type"),
                "username": info.get("username"),
                "binary_path": info.get("binpath"),
                "description": info.get("description"),
            }
        )
    return services


def collect_processes() -> list[dict[str, Any]]:
    processes: list[dict[str, Any]] = []
    attrs = ["pid", "name", "exe", "cmdline", "username", "status", "cwd", "ppid", "create_time"]
    for proc in psutil.process_iter(attrs=attrs):
        try:
            info = proc.info
            name = info.get("name") or f"pid-{info.get('pid')}"
            cmdline_list = info.get("cmdline") or []
            cmdline = " ".join(str(part) for part in cmdline_list)
            create_time = info.get("create_time")
            processes.append(
                {
                    "identity_key": process_identity(name, info.get("exe"), cmdline),
                    "name": name,
                    "exe_path": info.get("exe"),
                    "cmdline": cmdline,
                    "username": info.get("username"),
                    "status": info.get("status"),
                    "cwd": info.get("cwd"),
                    "last_pid": info.get("pid"),
                    "parent_pid": info.get("ppid"),
                    "create_time": datetime.fromtimestamp(create_time).astimezone().isoformat(timespec="seconds")
                    if create_time
                    else None,
                }
            )
        except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess, OSError):
            continue
    return processes


def run_full_scan() -> dict[str, Any]:
    started_at = now_iso()
    with get_db() as conn:
        cursor = conn.execute(
            "INSERT INTO scan_records (started_at, status) VALUES (?, 'RUNNING')",
            (started_at,),
        )
        scan_id = cursor.lastrowid

    try:
        services = collect_services()
        processes = collect_processes()
        scanned_at = now_iso()
        new_services = 0
        new_processes = 0

        with get_db() as conn:
            conn.execute("UPDATE windows_services SET is_present_now = 0")
            conn.execute("UPDATE windows_processes SET is_present_now = 0")

            for item in services:
                existing = conn.execute(
                    "SELECT id FROM windows_services WHERE identity_key = ?",
                    (item["identity_key"],),
                ).fetchone()
                if existing:
                    conn.execute(
                        """
                        UPDATE windows_services
                        SET display_name = ?, status = ?, start_type = ?, username = ?,
                            binary_path = ?, description = ?, is_present_now = 1,
                            last_seen_at = ?, updated_at = ?
                        WHERE identity_key = ?
                        """,
                        (
                            item["display_name"],
                            item["status"],
                            item["start_type"],
                            item["username"],
                            item["binary_path"],
                            item["description"],
                            scanned_at,
                            scanned_at,
                            item["identity_key"],
                        ),
                    )
                else:
                    new_services += 1
                    conn.execute(
                        """
                        INSERT INTO windows_services (
                            identity_key, name, display_name, status, start_type, username,
                            binary_path, description, is_present_now, first_seen_at,
                            last_seen_at, confirm_status, updated_at
                        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, 1, ?, ?, 'PENDING', ?)
                        """,
                        (
                            item["identity_key"],
                            item["name"],
                            item["display_name"],
                            item["status"],
                            item["start_type"],
                            item["username"],
                            item["binary_path"],
                            item["description"],
                            scanned_at,
                            scanned_at,
                            scanned_at,
                        ),
                    )

            for item in processes:
                existing = conn.execute(
                    "SELECT id FROM windows_processes WHERE identity_key = ?",
                    (item["identity_key"],),
                ).fetchone()
                if existing:
                    conn.execute(
                        """
                        UPDATE windows_processes
                        SET exe_path = ?, cmdline = ?, username = ?, status = ?, cwd = ?,
                            last_pid = ?, parent_pid = ?, create_time = ?,
                            is_present_now = 1, last_seen_at = ?, updated_at = ?
                        WHERE identity_key = ?
                        """,
                        (
                            item["exe_path"],
                            item["cmdline"],
                            item["username"],
                            item["status"],
                            item["cwd"],
                            item["last_pid"],
                            item["parent_pid"],
                            item["create_time"],
                            scanned_at,
                            scanned_at,
                            item["identity_key"],
                        ),
                    )
                else:
                    new_processes += 1
                    conn.execute(
                        """
                        INSERT INTO windows_processes (
                            identity_key, name, exe_path, cmdline, username, status, cwd,
                            last_pid, parent_pid, create_time, is_present_now,
                            first_seen_at, last_seen_at, confirm_status, updated_at
                        ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 1, ?, ?, 'PENDING', ?)
                        """,
                        (
                            item["identity_key"],
                            item["name"],
                            item["exe_path"],
                            item["cmdline"],
                            item["username"],
                            item["status"],
                            item["cwd"],
                            item["last_pid"],
                            item["parent_pid"],
                            item["create_time"],
                            scanned_at,
                            scanned_at,
                            scanned_at,
                        ),
                    )

            conn.execute(
                """
                UPDATE scan_records
                SET finished_at = ?, status = 'SUCCESS', services_found = ?,
                    processes_found = ?, new_services = ?, new_processes = ?
                WHERE id = ?
                """,
                (now_iso(), len(services), len(processes), new_services, new_processes, scan_id),
            )

        return {
            "scan_id": scan_id,
            "status": "SUCCESS",
            "services_found": len(services),
            "processes_found": len(processes),
            "new_services": new_services,
            "new_processes": new_processes,
        }
    except Exception as exc:
        with get_db() as conn:
            conn.execute(
                "UPDATE scan_records SET finished_at = ?, status = 'FAILED', error_message = ? WHERE id = ?",
                (now_iso(), str(exc), scan_id),
            )
        raise