"""Environment health checks for cross-eval."""
from __future__ import annotations

import shutil
import subprocess
from dataclasses import dataclass
from pathlib import Path
from typing import Optional


@dataclass
class DoctorCheck:
    """Result of a single health check."""

    name: str
    passed: bool
    critical: bool
    message: str
    detail: Optional[str] = None


def check_cli_installed(command: str) -> tuple[bool, str]:
    """Check if a CLI tool is on PATH and get its version."""
    path = shutil.which(command)
    if not path:
        return False, f"'{command}' not found on PATH"

    try:
        result = subprocess.run(
            [command, "--version"],
            capture_output=True,
            text=True,
            timeout=10,
        )
        version = (result.stdout.strip() or result.stderr.strip()).split("\n")[0]
        return True, version or "(version unknown)"
    except (subprocess.TimeoutExpired, OSError):
        return True, "(installed but version check failed)"


def check_cli_authenticated(command: str) -> tuple[bool, str]:
    """Check if a CLI tool is authenticated by running a minimal probe."""
    path = shutil.which(command)
    if not path:
        return False, "not installed"

    if command == "claude":
        try:
            result = subprocess.run(
                [command, "-p", "--model", "haiku", "--max-turns", "1"],
                input="respond with just 'ok'",
                capture_output=True,
                text=True,
                timeout=30,
            )
            combined = result.stdout + result.stderr
            if any(kw in combined.lower() for kw in (
                "not logged in", "login", "unauthorized", "unauthenticated",
                "api key", "invalid key",
            )):
                return False, "not authenticated — run: claude login"
            if result.returncode == 0:
                return True, "authenticated"
            return False, f"exit code {result.returncode}: {combined[:100]}"
        except subprocess.TimeoutExpired:
            return False, "timed out (30s) — possible network issue"
        except OSError as e:
            return False, str(e)

    elif command == "codex":
        try:
            result = subprocess.run(
                [command, "--version"],
                capture_output=True,
                text=True,
                timeout=10,
            )
            combined = result.stdout + result.stderr
            if any(kw in combined.lower() for kw in (
                "not logged in", "login", "unauthorized", "api key",
            )):
                return False, "not authenticated — run: codex login"
            return True, "installed (auth check: codex login if needed)"
        except (subprocess.TimeoutExpired, OSError) as e:
            return False, str(e)

    return False, f"unknown command: {command}"


def check_config(directory: Path) -> tuple[bool, Optional[Path], list[str]]:
    """Check if config.yaml exists and is valid."""
    config_path = directory / ".cross-eval" / "config.yaml"
    if not config_path.exists():
        return False, None, []

    try:
        from cross_eval.config import load_config
        load_config(config_path)
        return True, config_path, []
    except (ValueError, FileNotFoundError) as e:
        return False, config_path, [str(e)]


def run_doctor(directory: Path) -> list[DoctorCheck]:
    """Run all health checks and return results."""
    checks: list[DoctorCheck] = []

    # 1. claude CLI
    installed, version = check_cli_installed("claude")
    checks.append(DoctorCheck(
        name="claude CLI",
        passed=installed,
        critical=True,
        message=version if installed else "not found",
        detail="Install: https://docs.anthropic.com/en/docs/claude-code" if not installed else None,
    ))

    if installed:
        auth_ok, auth_msg = check_cli_authenticated("claude")
        checks.append(DoctorCheck(
            name="claude auth",
            passed=auth_ok,
            critical=True,
            message=auth_msg,
        ))

    # 2. codex CLI
    installed, version = check_cli_installed("codex")
    checks.append(DoctorCheck(
        name="codex CLI",
        passed=installed,
        critical=False,
        message=version if installed else "not found (optional)",
        detail="Install: https://github.com/openai/codex" if not installed else None,
    ))

    if installed:
        auth_ok, auth_msg = check_cli_authenticated("codex")
        checks.append(DoctorCheck(
            name="codex auth",
            passed=auth_ok,
            critical=False,
            message=auth_msg,
        ))

    # 3. Config
    config_ok, config_path, config_errors = check_config(directory)
    if config_path is None:
        checks.append(DoctorCheck(
            name="config",
            passed=True,  # not having config is fine
            critical=False,
            message="no .cross-eval/config.yaml (will use defaults)",
            detail="Run: cross-eval init",
        ))
    elif config_ok:
        checks.append(DoctorCheck(
            name="config",
            passed=True,
            critical=False,
            message=f"valid ({config_path.name})",
        ))
    else:
        checks.append(DoctorCheck(
            name="config",
            passed=False,
            critical=True,
            message="invalid config",
            detail="\n".join(config_errors),
        ))

    return checks


def format_doctor_results(checks: list[DoctorCheck]) -> str:
    """Format doctor check results for terminal output."""
    lines: list[str] = []
    lines.append("\n  cross-eval doctor\n")

    for check in checks:
        icon = "  ✓" if check.passed else "  ✗"
        lines.append(f"{icon} {check.name}: {check.message}")
        if check.detail and not check.passed:
            for detail_line in check.detail.split("\n"):
                lines.append(f"    {detail_line}")

    # Summary
    failed_critical = [c for c in checks if not c.passed and c.critical]
    failed_warn = [c for c in checks if not c.passed and not c.critical]

    lines.append("")
    if not failed_critical and not failed_warn:
        lines.append("  All checks passed!")
    elif failed_critical:
        lines.append(f"  {len(failed_critical)} critical issue(s) found.")
    else:
        lines.append(f"  {len(failed_warn)} warning(s), no critical issues.")

    lines.append("")
    return "\n".join(lines)