"""Pre-deploy environment validation for EC2 deployment."""

from __future__ import annotations

import os
import sys
from collections.abc import Callable
from dataclasses import dataclass

import boto3

from config.config import get_configured_llm_provider, get_llm_provider_api_key_env
from config.llm_auth import KEYLESS_PROVIDER_VALUES, SUPPORTED_PROVIDER_VALUES, provider_spec
from config.local_env import bootstrap_opensre_env, get_project_env_path

_DEPLOY_ENV_EXAMPLE = ".env.deploy.example"

# Fixed user-facing labels only — avoid credential-related substrings in print()
# paths (CodeQL clear-text logging).
_MISSING_LABELS: dict[str, str] = {
    "aws": "AWS account access for EC2 provisioning",
    "telegram_bot": "Telegram gateway bot configuration",
    "llm_provider_invalid": "LLM provider setting (unsupported value)",
    "llm_api": "LLM provider configuration for the selected provider",
}
_WARNING_LABELS: dict[str, str] = {
    "telegram_users": "Telegram allowed-users configuration (recommended)",
    "llm_provider_ec2": "LLM provider may not work inside EC2 containers",
}


class DeployEnvValidationError(Exception):
    """Raised after printing the deploy env validation report."""


@dataclass(frozen=True)
class DeployEnvIssue:
    """A deploy env validation issue identified by a stable code."""

    code: str
    env_vars: tuple[str, ...] = ()
    provider: str = ""


def _env_set(name: str) -> bool:
    return bool(os.getenv(name, "").strip())


def _aws_credentials_available() -> bool:
    if _env_set("AWS_ROLE_ARN"):
        return True
    if _env_set("AWS_ACCESS_KEY_ID") and _env_set("AWS_SECRET_ACCESS_KEY"):
        return True
    if _env_set("AWS_PROFILE"):
        return True
    try:
        credentials = boto3.Session().get_credentials()
    except Exception:  # noqa: BLE001
        return False
    return credentials is not None


def _collect_deploy_env_issues() -> tuple[list[DeployEnvIssue], list[DeployEnvIssue]]:
    """Return ``(missing_required, warnings)`` for the current process env."""
    bootstrap_opensre_env(override=False)

    missing: list[DeployEnvIssue] = []
    warnings: list[DeployEnvIssue] = []

    if not _aws_credentials_available():
        missing.append(DeployEnvIssue("aws"))

    if not _env_set("TELEGRAM_BOT_TOKEN"):
        missing.append(DeployEnvIssue("telegram_bot", env_vars=("TELEGRAM_BOT_TOKEN",)))

    if not _env_set("TELEGRAM_ALLOWED_USERS"):
        warnings.append(DeployEnvIssue("telegram_users", env_vars=("TELEGRAM_ALLOWED_USERS",)))

    provider = get_configured_llm_provider()
    if provider not in SUPPORTED_PROVIDER_VALUES:
        missing.append(DeployEnvIssue("llm_provider_invalid", env_vars=("LLM_PROVIDER",)))
    else:
        api_key_env = get_llm_provider_api_key_env(provider)
        if api_key_env and not _env_set(api_key_env):
            missing.append(DeployEnvIssue("llm_api", env_vars=(api_key_env,), provider=provider))
        elif provider in KEYLESS_PROVIDER_VALUES:
            spec = provider_spec(provider)
            if spec is not None and spec.credential_kind in {"cli", "local"}:
                warnings.append(DeployEnvIssue("llm_provider_ec2"))

    return missing, warnings


def _supports_color() -> bool:
    return sys.stdout.isatty() and os.getenv("NO_COLOR", "").strip() == ""


def _highlight(text: str, *, kind: str) -> str:
    if not _supports_color():
        return text
    if kind == "missing":
        return f"\033[31m{text}\033[0m"
    if kind == "warn":
        return f"\033[33m{text}\033[0m"
    if kind == "label":
        return f"\033[1m{text}\033[0m"
    return text


def _label_for_issue(issue: DeployEnvIssue, *, warning: bool) -> str:
    labels = _WARNING_LABELS if warning else _MISSING_LABELS
    return labels.get(issue.code, "Deploy environment configuration")


def _format_issue_message(issue: DeployEnvIssue, *, warning: bool) -> str:
    label = _label_for_issue(issue, warning=warning)

    if issue.code == "telegram_bot" and issue.env_vars:
        return f"{issue.env_vars[0]} — API key not set ({label})"

    if issue.code == "llm_api" and issue.env_vars:
        provider = issue.provider or "selected provider"
        return f"{issue.env_vars[0]} — API key not set (required for LLM provider: {provider})"

    if issue.code == "aws":
        return (
            "AWS credentials — not configured "
            "(set AWS_ACCESS_KEY_ID + AWS_SECRET_ACCESS_KEY, AWS_ROLE_ARN, or AWS_PROFILE)"
        )

    if issue.code == "llm_provider_invalid" and issue.env_vars:
        return f"{issue.env_vars[0]} — unsupported or missing value ({label})"

    if issue.code == "telegram_users" and issue.env_vars:
        return f"{issue.env_vars[0]} — not set ({label})"

    return label


def _print_deploy_env_report(missing: list[DeployEnvIssue], warnings: list[DeployEnvIssue]) -> None:
    env_path = get_project_env_path()
    print("=" * 60)
    print(_highlight("Deploy environment validation", kind="label"))
    print("=" * 60)

    if missing:
        print()
        print(_highlight("Missing required:", kind="label"))
        for issue in missing:
            message = _format_issue_message(issue, warning=False)
            print(f"  {_highlight('MISSING', kind='missing')}: {message}")

    if warnings:
        print()
        print(_highlight("Recommended:", kind="label"))
        for issue in warnings:
            message = _format_issue_message(issue, warning=True)
            print(f"  {_highlight('WARN', kind='warn')}: {message}")

    if missing or warnings:
        print()
        print(f"Env file: {env_path}")
        print(f"Template: {_DEPLOY_ENV_EXAMPLE}")
        print()

    if missing:
        print(
            f"Deploy aborted: {len(missing)} required environment variable(s) missing. "
            f"Fix the items above and retry."
        )
        print()


def validate_deploy_env() -> None:
    """Fail fast when required deploy environment variables are missing."""
    missing, warnings = _collect_deploy_env_issues()
    if not missing and not warnings:
        return

    _print_deploy_env_report(missing, warnings)

    if missing:
        raise DeployEnvValidationError


def run_lifecycle_main(main: Callable[[], None]) -> None:
    """Run a deploy lifecycle CLI entrypoint with clean env-validation exits."""
    try:
        main()
    except DeployEnvValidationError:
        raise SystemExit(1) from None