"""
QGIS 环境配置模块 — Docker 模式。

所有 QGIS 操作通过 docker exec 在容器内执行，
主进程（Python 3.10）无需安装 QGIS 或处理 DLL 加载。

容器内使用 qgis/qgis 官方镜像（QGIS 3.x + Python 3）。

本模块提供：
  - get_docker_container():      获取 Docker 容器名称
  - get_docker_project_dir():    获取容器内项目根目录
  - build_docker_exec_cmd():     构建 docker exec 命令
  - build_docker_volume_mounts(): 构建 docker run 卷挂载参数
  - get_runner_script():         获取 qgis_runner.py 的绝对路径
  - get_container_python_path(): 获取容器内 Python 解释器路径
"""
import os
import platform
from pathlib import Path

from app.config.paths import get_logger

logger = get_logger("qgis.env")

IS_WINDOWS = platform.system() == "Windows"


# ============================================================
# Docker 容器配置
# ============================================================

def get_docker_container() -> str:
    """获取 Docker 容器名称/ID"""
    try:
        from config import settings
        container = getattr(settings, "QGIS_DOCKER_CONTAINER", "") or ""
        if container.strip():
            return container.strip()
    except Exception:
        pass
    # 环境变量覆盖
    env_container = os.environ.get("QGIS_DOCKER_CONTAINER", "")
    if env_container.strip():
        return env_container.strip()
    return "qgis-server"


def get_docker_project_dir() -> str:
    """获取容器内项目根目录（代码挂载目标路径）"""
    try:
        from config import settings
        project_dir = getattr(settings, "QGIS_DOCKER_PROJECT_DIR", "") or ""
        if project_dir.strip():
            return project_dir.strip()
    except Exception:
        pass
    env_dir = os.environ.get("QGIS_DOCKER_PROJECT_DIR", "")
    if env_dir.strip():
        return env_dir.strip()
    return "/app"


def get_container_python_path() -> str:
    """获取容器内 Python 解释器路径"""
    try:
        from config import settings
        python_path = getattr(settings, "QGIS_DOCKER_PYTHON", "") or ""
        if python_path.strip():
            return python_path.strip()
    except Exception:
        pass
    env_path = os.environ.get("QGIS_DOCKER_PYTHON", "")
    if env_path.strip():
        return env_path.strip()
    # qgis/qgis 官方镜像默认路径
    return "/usr/bin/python3"


# ============================================================
# docker exec 命令构建
# ============================================================

def build_docker_exec_cmd(python_path: str, runner_script: str, json_file: str) -> list:
    """
    构建 docker exec 命令。

    Args:
        python_path: 容器内 Python 路径（如 /usr/bin/python3）
        runner_script: 容器内 runner 脚本路径
        json_file: 容器内 JSON 请求文件路径

    Returns:
        docker exec 命令列表
    """
    container = get_docker_container()
    project_dir = get_docker_project_dir()

    # Qt 平台插件（从配置读取，避免硬编码）
    try:
        from config import settings
        qt_platform = getattr(settings, "QGIS_DOCKER_QT_PLATFORM", "offscreen")
    except Exception:
        qt_platform = "offscreen"

    cmd = [
        "docker", "exec",
        "-w", project_dir,
        "-e", f"QT_QPA_PLATFORM={qt_platform}",
        container,
        python_path, runner_script, json_file,
    ]
    return cmd


# ============================================================
# docker run 卷挂载（首次启动容器用）
# ============================================================

def get_host_file_store() -> str:
    """获取主机端文件输出目录"""
    try:
        from config import settings
        fs = getattr(settings, "FILE_STORE_DIR", "") or ""
        if fs.strip():
            return fs.strip().replace("\\", "/")
    except Exception:
        pass
    return "G:/files"


def get_container_file_store() -> str:
    """获取容器内文件输出目录（Linux 路径）"""
    # 挂载时主机 G:/files → 容器内 /files
    host = get_host_file_store()
    # 取最后一段目录名作为容器内路径
    tail = host.rstrip("/").rsplit("/", 1)[-1]
    return f"/{tail}"


def map_host_to_container(path: str) -> str:
    """将主机路径映射为容器内路径。
    优先匹配 file_store（G:/files → /files），其次匹配项目根目录（F:/project/... → /app）。
    """
    normalized = path.replace("\\", "/")

    # 1. file_store 路径映射
    host_fs = get_host_file_store()
    container_fs = get_container_file_store()
    if normalized.lower().startswith(host_fs.lower()):
        return container_fs + normalized[len(host_fs):]

    # 2. 项目根目录映射
    project_root = str(Path(__file__).parent.parent.parent.parent).replace("\\", "/")
    project_dir = get_docker_project_dir()
    if normalized.lower().startswith(project_root.lower()):
        return project_dir + normalized[len(project_root):]

    return normalized


def map_container_to_host(path: str) -> str:
    """将容器内路径映射回主机路径"""
    host = get_host_file_store()
    container = get_container_file_store()
    if path.startswith(container):
        return host + path[len(container):]
    return path


def build_docker_volume_mounts() -> list:
    """
    构建 Docker 卷挂载参数列表（用于 docker run）。

    挂载内容：
      1. 项目代码目录 → 容器内 /app（只读）
      2. 输出文件目录 → 容器内 /files（读写）
    """
    project_root = str(Path(__file__).parent.parent.parent.parent)
    host_file_store = get_host_file_store()
    container_file_store = get_container_file_store()
    project_dir = get_docker_project_dir()

    mounts = [
        f"{project_root}:{project_dir}:ro",
        f"{host_file_store}:{container_file_store}",
    ]
    return mounts


def build_docker_run_cmd(image: str = None) -> list:
    """
    构建 docker run 启动命令（首次部署用）。

    Returns:
        docker run 命令列表
    """
    if image is None:
        try:
            from config import settings
            image = getattr(settings, "QGIS_DOCKER_IMAGE", "") or ""
            if not image.strip():
                image = "qgis/qgis:latest"
        except Exception:
            image = "qgis/qgis:latest"

    # 容器保活命令（从配置读取）
    try:
        from config import settings
        keep_alive = getattr(settings, "QGIS_DOCKER_KEEP_ALIVE", "sleep infinity")
    except Exception:
        keep_alive = "sleep infinity"

    container = get_docker_container()
    mounts = build_docker_volume_mounts()

    cmd = [
        "docker", "run", "-d",
        "--name", container,
        "--restart", "unless-stopped",
    ]
    for m in mounts:
        cmd.extend(["-v", m])

    cmd.append(image)
    # 保活命令
    cmd.extend(keep_alive.split())
    return cmd


# ============================================================
# Runner 脚本路径
# ============================================================

def get_runner_script() -> str:
    """获取 qgis_runner.py 的绝对路径（主机端）"""
    return str(Path(__file__).parent / "qgis_runner.py")