from __future__ import annotations

import importlib.util
import os
import shutil
import sys
from dataclasses import dataclass
from pathlib import Path

from copienator.platform import windows_filename_problems


@dataclass(frozen=True)
class DiagnosticCheck:
    name: str
    ok: bool
    detail: str
    required: bool = True


def module_available(module: str) -> bool:
    try:
        return importlib.util.find_spec(module) is not None
    except (ImportError, ModuleNotFoundError, ValueError):
        return False


def collect_diagnostics(
    show_personal_steps: bool,
    api_key_override: str = "",
    evaluation: Path | None = None,
) -> list[DiagnosticCheck]:
    checks = [
        DiagnosticCheck(
            "Système",
            os.name == "nt" or sys.platform.startswith("linux"),
            f"{sys.platform} — Linux et Windows sont pris en charge",
        ),
        DiagnosticCheck("Python", True, sys.executable),
    ]

    modules = {
        "numpy": "numpy",
        "pandas": "pandas",
        "matplotlib": "matplotlib",
        "Pillow": "PIL",
        "pydantic": "pydantic",
        "pypdf": "pypdf",
        "pdf2image": "pdf2image",
        "reportlab": "reportlab",
        "img2pdf": "img2pdf",
        "PyMuPDF": "fitz",
        "ftfy": "ftfy",
        "ezodf": "ezodf",
        "Google GenAI": "google.genai",
    }
    checks.extend(
        DiagnosticCheck(label, module_available(module), f"Module Python : {module}")
        for label, module in modules.items()
    )

    programs = (
        ("Poppler", ("pdftoppm", "pdftocairo"), True),
        ("LaTeX", ("pdflatex",), True),
        ("PDF Arranger", ("pdf-arranger", "pdfarranger"), False),
    )
    for label, candidates, required in programs:
        executable = next((shutil.which(candidate) for candidate in candidates if shutil.which(candidate)), None)
        detail = executable or "Introuvable dans PATH"
        checks.append(DiagnosticCheck(label, executable is not None, detail, required))

    api_key = api_key_override.strip() or os.environ.get("GEMINI_API_KEY")
    checks.append(
        DiagnosticCheck(
            "Clé Gemini",
            bool(api_key),
            "GEMINI_API_KEY est définie" if api_key else "À saisir dans le GUI ou dans l’environnement",
        )
    )

    if evaluation and (evaluation / "labels").is_file():
        labels = [
            line.strip()
            for line in (evaluation / "labels").read_text(encoding="utf-8").splitlines()
            if line.strip()
        ]
        unsafe = [label for label in labels if windows_filename_problems(label)]
        detail = (
            "Tous les labels sont utilisables comme noms de fichiers"
            if not unsafe
            else "Caractères Windows interdits : " + ", ".join(unsafe[:3])
        )
        if len(unsafe) > 3:
            detail += f" (+{len(unsafe) - 3})"
        checks.append(
            DiagnosticCheck(
                "Labels compatibles Windows",
                not unsafe,
                detail,
                os.name == "nt",
            )
        )

    if show_personal_steps:
        checks.append(
            DiagnosticCheck(
                "gestion_classe",
                shutil.which("gestion_classe") is not None,
                shutil.which("gestion_classe") or "Introuvable dans PATH",
                False,
            )
        )
        try:
            from copienator.configuration import CURRENT_SCORE_ODS_PATH, FINAL_SCORE_ODS_PATH

            for label, configured_path in (
                ("ODS courant", CURRENT_SCORE_ODS_PATH),
                ("ODS final", FINAL_SCORE_ODS_PATH),
            ):
                path = Path(configured_path).expanduser()
                checks.append(DiagnosticCheck(label, path.is_file(), str(path), False))
        except ImportError:
            checks.append(DiagnosticCheck("Configuration personnelle", False, "Variables absentes", False))

    return checks