"""
检测系统依赖工具
用于检测 PDF 生成所需的系统依赖
"""
import os
import sys
import platform
from pathlib import Path
from loguru import logger
from ctypes import util as ctypes_util

BOX_CONTENT_WIDTH = 62


def _box_line(text: str = "") -> str:
    """Render a single line inside the 66-char help box."""
    return f"║  {text:<{BOX_CONTENT_WIDTH}}║\n"


def _get_platform_specific_instructions():
    """
    获取针对当前平台的安装说明

    Returns:
        str: 平台特定的安装说明
    """
    system = platform.system()

    def _box_lines(lines):
        """批量将多行文本包装成带边框的提示块"""
        return "".join(_box_line(line) for line in lines)

    if system == "Darwin":  # macOS
        return _box_lines(
            [
                "🍎 macOS 系统解决方案：",
                "",
                "步骤 1: 安装依赖（宿主机执行）",
                "  brew install pango gdk-pixbuf libffi",
                "",
                "步骤 2: 设置 DYLD_LIBRARY_PATH（必做）",
                "  Apple Silicon:",
                " export DYLD_LIBRARY_PATH=/opt/homebrew/lib:$DYLD_LIBRARY_PATH",
                "  Intel:",
                " export DYLD_LIBRARY_PATH=/usr/local/lib:$DYLD_LIBRARY_PATH",
                "",
                "步骤 3: 永久生效（推荐）",
                "  将 export DYLD_LIBRARY_PATH=... 追加到 ~/.zshrc",
                "  Apple 用 /opt/homebrew/lib，Intel 用 /usr/local/lib",
                "  执行 source ~/.zshrc 后再打开新终端",
                "",
                "步骤 4: 新开终端执行验证",
                "  python -m ReportEngine.utils.dependency_check",
                "  输出含 “✓ Pango 依赖检测通过” 即配置正确",
            ]
        )
    elif system == "Linux":
        return _box_lines(
            [
                "🐧 Linux 系统解决方案：",
                "",
                "Ubuntu/Debian（宿主机执行）：",
                "  sudo apt-get update",
                "  sudo apt-get install -y \\",
                "    libpango-1.0-0 libpangoft2-1.0-0 libffi-dev libcairo2",
                "    libgdk-pixbuf-2.0-0（缺失时改为 libgdk-pixbuf2.0-0）",
                "",
                "CentOS/RHEL：",
                "  sudo yum install -y pango gdk-pixbuf2 libffi-devel cairo",
                "",
                "Docker 部署无需额外安装，镜像已包含依赖",
            ]
        )
    elif system == "Windows":
        return _box_lines(
            [
                "🪟 Windows 系统解决方案：",
                "",
                "步骤 1: 安装 GTK3 Runtime（宿主机执行）",
                "  下载页: README 中的 GTK3 Runtime 链接（建议默认路径）",
                "",
                "步骤 2: 将 GTK 安装目录下的 bin 加入 PATH（需新终端）",
                "  set PATH=C:\\Program Files\\GTK3-Runtime Win64\\bin;%PATH%",
                "  自定义路径请替换，或设置环境变量 GTK_BIN_PATH",
                "  可选: 永久添加 PATH 示例:",
                "    setx PATH \"C:\\Program Files\\GTK3-Runtime Win64\\bin;%PATH%\"",
                "",
                "步骤 3: 验证（新终端执行）",
                "  python -m ReportEngine.utils.dependency_check",
                "  输出含 “✓ Pango 依赖检测通过” 即配置正确",
            ]
        )
    else:
        return _box_lines(["请查看 PDF 导出 README 了解您系统的安装方法"])


def _ensure_windows_gtk_paths():
    """
    为 Windows 自动补充 GTK/Pango 运行时搜索路径，解决 DLL 未找到问题。

    Returns:
        str | None: 成功添加的路径（没有命中则为 None）
    """
    if platform.system() != "Windows":
        return None

    candidates = []
    seen = set()

    def _add_candidate(path_like):
        """收集可能的GTK安装路径，避免重复并兼容用户自定义目录"""
        if not path_like:
            return
        p = Path(path_like)
        # 如果传入的是安装根目录，尝试拼接 bin
        if p.is_dir() and p.name.lower() == "bin":
            key = str(p.resolve()).lower()
            if key not in seen:
                seen.add(key)
                candidates.append(p)
        else:
            for maybe in (p, p / "bin"):
                key = str(maybe.resolve()).lower()
                if maybe.exists() and key not in seen:
                    seen.add(key)
                    candidates.append(maybe)

    # 用户自定义提示优先
    for env_var in ("GTK3_RUNTIME_PATH", "GTK_RUNTIME_PATH", "GTK_BIN_PATH", "GTK_BIN_DIR", "GTK_PATH"):
        _add_candidate(os.environ.get(env_var))

    program_files = os.environ.get("ProgramFiles", r"C:\\Program Files")
    program_files_x86 = os.environ.get("ProgramFiles(x86)", r"C:\\Program Files (x86)")
    default_dirs = [
        Path(program_files) / "GTK3-Runtime Win64",
        Path(program_files_x86) / "GTK3-Runtime Win64",
        Path(program_files) / "GTK3-Runtime Win32",
        Path(program_files_x86) / "GTK3-Runtime Win32",
        Path(program_files) / "GTK3-Runtime",
        Path(program_files_x86) / "GTK3-Runtime",
    ]

    # 常见自定义安装位置（其他盘符 / DevelopSoftware 目录）
    common_drives = ["C", "D", "E", "F"]
    common_names = ["GTK3-Runtime Win64", "GTK3-Runtime Win32", "GTK3-Runtime"]
    for drive in common_drives:
        root = Path(f"{drive}:/")
        for name in common_names:
            default_dirs.append(root / name)
            default_dirs.append(root / "DevelopSoftware" / name)

    # 扫描 Program Files 下所有以 GTK 开头的目录，适配自定义安装目录名
    for root in (program_files, program_files_x86):
        root_path = Path(root)
        if root_path.exists():
            for child in root_path.glob("GTK*"):
                default_dirs.append(child)

    for d in default_dirs:
        _add_candidate(d)

    # 如果用户已把自定义路径加入 PATH，也尝试识别
    path_entries = os.environ.get("PATH", "").split(os.pathsep)
    for entry in path_entries:
        if not entry:
            continue
        # 粗筛包含 gtk 或 pango 的目录
        if "gtk" in entry.lower() or "pango" in entry.lower():
            _add_candidate(entry)

    for path in candidates:
        if not path or not path.exists():
            continue
        if not any(path.glob("pango*-1.0-*.dll")) and not (path / "pango-1.0-0.dll").exists():
            continue

        try:
            if hasattr(os, "add_dll_directory"):
                os.add_dll_directory(str(path))
        except Exception:
            # 如果添加失败，继续尝试 PATH 方式
            pass

        current_path = os.environ.get("PATH", "")
        if str(path) not in current_path.split(";"):
            os.environ["PATH"] = f"{path};{current_path}"

        return str(path)

    return None


def prepare_pango_environment():
    """
    初始化运行所需的本地依赖搜索路径（当前主要针对 Windows 和 macOS）。

    Returns:
        str | None: 成功添加的路径（没有命中则为 None）
    """
    system = platform.system()
    if system == "Windows":
        return _ensure_windows_gtk_paths()
    if system == "Darwin":
        # 自动补全 DYLD_LIBRARY_PATH，兼容 Apple Silicon 与 Intel
        candidates = [Path("/opt/homebrew/lib"), Path("/usr/local/lib")]
        current = os.environ.get("DYLD_LIBRARY_PATH", "")
        added = []
        for c in candidates:
            if c.exists() and str(c) not in current.split(":"):
                added.append(str(c))
        if added:
            os.environ["DYLD_LIBRARY_PATH"] = ":".join(added + ([current] if current else []))
            return os.environ["DYLD_LIBRARY_PATH"]
    return None


def _probe_native_libs():
    """
    使用 ctypes 查找关键原生库，帮助定位缺失组件。

    Returns:
        list[str]: 未找到的库标识
    """
    system = platform.system()
    targets = []

    if system == "Windows":
        targets = [
            ("pango", ["pango-1.0-0"]),
            ("gobject", ["gobject-2.0-0"]),
            ("gdk-pixbuf", ["gdk_pixbuf-2.0-0"]),
            ("cairo", ["cairo-2"]),
        ]
    else:
        targets = [
            ("pango", ["pango-1.0"]),
            ("gobject", ["gobject-2.0"]),
            ("gdk-pixbuf", ["gdk_pixbuf-2.0"]),
            ("cairo", ["cairo", "cairo-2"]),
        ]

    missing = []
    for key, variants in targets:
        found = any(ctypes_util.find_library(v) for v in variants)
        if not found:
            missing.append(key)
    return missing


def check_pango_available():
    """
    检测 Pango 库是否可用

    Returns:
        tuple: (is_available: bool, message: str)
    """
    added_path = prepare_pango_environment()
    missing_native = _probe_native_libs()

    try:
        # 尝试导入 weasyprint 并初始化 Pango
        from weasyprint import HTML
        from weasyprint.text.ffi import ffi, pango

        # 尝试调用 Pango 函数来确认库可用
        pango.pango_version()

        return True, "✓ Pango 依赖检测通过，PDF 导出功能可用"
    except OSError as e:
        # Pango 库未安装或无法加载
        error_msg = str(e)
        platform_instructions = _get_platform_specific_instructions()
        windows_hint = ""
        if platform.system() == "Windows":
            prefix = "已尝试自动添加 GTK 路径: "
            max_path_len = BOX_CONTENT_WIDTH - len(prefix)
            path_display = added_path or "未找到默认路径"
            if len(path_display) > max_path_len:
                path_display = path_display[: max_path_len - 3] + "..."
            windows_hint = _box_line(prefix + path_display)
            arch_note = _box_line("🔍 若已安装仍报错：确认 Python 与 GTK 位数一致后重开终端")
        else:
            arch_note = ""

        missing_note = ""
        if missing_native:
            missing_str = ", ".join(missing_native)
            missing_note = _box_line(f"未识别到的依赖: {missing_str}")

        if 'gobject' in error_msg.lower() or 'pango' in error_msg.lower() or 'gdk' in error_msg.lower():
            box_top = "╔" + "═" * 64 + "╗\n"
            box_bottom = "╚" + "═" * 64 + "╝"
            return False, (
                box_top
                + _box_line("⚠️  PDF 导出依赖缺失")
                + _box_line()
                + _box_line("📄 PDF 导出功能将不可用（其他功能不受影响）")
                + _box_line()
                + windows_hint
                + arch_note
                + missing_note
                + platform_instructions
                + _box_line()
                + _box_line("📖 文档：static/Partial README for PDF Exporting/README.md")
                + box_bottom
            )
        return False, f"⚠ PDF 依赖加载失败: {error_msg}；缺失/未识别: {', '.join(missing_native) if missing_native else '未知'}"
    except ImportError as e:
        # weasyprint 未安装
        return False, (
            "⚠ WeasyPrint 未安装\n"
            "解决方法: pip install weasyprint"
        )
    except Exception as e:
        # 其他未知错误
        return False, f"⚠ PDF 依赖检测失败: {e}"


def log_dependency_status():
    """
    记录系统依赖状态到日志
    """
    is_available, message = check_pango_available()

    if is_available:
        logger.success(message)
    else:
        logger.warning(message)
        logger.info("💡 提示：PDF 导出功能需要 Pango 库支持，但不影响系统其他功能的正常使用")
        logger.info("📚 安装说明请参考：static/Partial README for PDF Exporting/README.md")

    return is_available


if __name__ == "__main__":
    # 用于独立测试
    is_available, message = check_pango_available()
    print(message)
    sys.exit(0 if is_available else 1)