"""Regression guards for canonical documentation and instruction contracts."""

from __future__ import annotations

import re
from pathlib import Path

from transcription.config import Settings

PROJECT_ROOT = Path(__file__).resolve().parents[1]


ACTIVE_CONTRACT_FILES = (
    ".github/instructions/services.instructions.md",
    ".github/instructions/ui.instructions.md",
    ".github/instructions/error-handling.instructions.md",
    ".github/skills/python-code-reviewer/skill.md",
    ".github/skills/evidence-provenance-auditor/skill.md",
    "docs/index.md",
    "docs/architecture.md",
    "docs/requirements.md",
    "docs/schema.md",
    "docs/error_handling.md",
    "docs/ui/README.md",
)


LEGACY_REFERENCE_MARKERS = (
    "docs-v4x-archive",
    "docs/ver4/history.md",
    "docs/ver4.0",
    "docs/ver4.1",
    "docs/ver4.2",
    "docs/ver4.3",
    "docs/ver4.4",
    "docs/ver4.5",
    "docs/ver4.6",
    "docs/ver4.7",
)


def _read(relative_path: str) -> str:
    return (PROJECT_ROOT / relative_path).read_text(encoding="utf-8")


def test_active_contract_files_are_present():
    """Guard the guard: ensure all expected authority files are scanned."""
    missing = [path for path in ACTIVE_CONTRACT_FILES if not (PROJECT_ROOT / path).exists()]
    assert missing == []


def test_no_legacy_authority_references_in_active_contract_files():
    """Active contracts must not route authority through removed revision trees."""
    violations: dict[str, list[str]] = {}
    for relative_path in ACTIVE_CONTRACT_FILES:
        text = _read(relative_path)
        found = [marker for marker in LEGACY_REFERENCE_MARKERS if marker in text]
        if found:
            violations[relative_path] = found
    assert violations == {}


def test_canonical_authority_references_are_present():
    """Critical instruction and skill files must keep canonical references explicit."""
    required_fragments = {
        ".github/instructions/services.instructions.md": (
            "docs/",
            "./error-handling.instructions.md",
            "src/transcription/db/models.py",
            "docs/schema.md",
            "append-only",
        ),
        ".github/instructions/ui.instructions.md": (
            "docs/",
            "./error-handling.instructions.md",
            "src/transcription/db/models.py",
            "docs/schema.md",
        ),
        ".github/instructions/error-handling.instructions.md": (
            "docs/error_handling.md",
            "docs/requirements.md",
        ),
        ".github/skills/python-code-reviewer/skill.md": (
            "docs/*",
            "docs/schema.md",
            ".github/instructions/error-handling.instructions.md",
        ),
        ".github/skills/evidence-provenance-auditor/skill.md": (
            "docs/schema.md",
            "docs/requirements.md",
            "docs/error_handling.md",
        ),
    }

    missing: dict[str, list[str]] = {}
    for relative_path, fragments in required_fragments.items():
        text = _read(relative_path)
        absent = [fragment for fragment in fragments if fragment not in text]
        if absent:
            missing[relative_path] = absent
    assert missing == {}


def _declared_env_production_example_keys(*, include_commented: bool) -> set[str]:
    text = _read(".env.production.example")
    pattern = r"^\s*#?\s*([A-Z0-9_]+)\s*=" if include_commented else r"^\s*([A-Z0-9_]+)\s*="
    return {match.group(1) for match in re.finditer(pattern, text, flags=re.MULTILINE)}


def _active_env_production_example_values() -> dict[str, str]:
    text = _read(".env.production.example")
    return {key: value.strip() for key, value in re.findall(r"^\s*([A-Z0-9_]+)\s*=\s*(.*)$", text, flags=re.MULTILINE)}


def _normalize_env_path_value(value: str | None) -> str | None:
    if value is None:
        return None
    normalized = value.strip().replace("\\", "/")
    while normalized.startswith("./"):
        normalized = normalized[2:]
    return normalized


def test_env_production_example_keys_match_runtime_settings_contract():
    """Guard against .env.production.example drift from Settings keys."""
    declared = _declared_env_production_example_keys(include_commented=True)
    settings_keys = {field.upper() for field in Settings.model_fields if field != "database"}
    database_keys = {
        "DATABASE__DRIVER",
        "DATABASE__PATH",
        "DATABASE__HOST",
        "DATABASE__PORT",
        "DATABASE__DATABASE",
        "DATABASE__USER",
        "DATABASE__PASSWORD",
    }
    deployment_helper_keys = {
        "CLOUDFLARE_TUNNEL_TOKEN",
        "RUNTIME_SETTINGS_ENV_FILE",
        "BACKUP_DIR",
        "BACKUP_RETENTION_DAYS",
    }
    allowed = settings_keys | database_keys | deployment_helper_keys

    missing = sorted(allowed - declared)
    unknown = sorted(declared - allowed)
    assert missing == []
    assert unknown == []


def test_env_production_example_builds_settings_and_keeps_production_defaults():
    """The production template must parse into Settings and preserve intended production posture."""
    active = _active_env_production_example_values()
    Settings(_env_file=PROJECT_ROOT / ".env.production.example", _cli_parse_args=False)

    assert active["ENVIRONMENT"] == "production"
    assert active["RUN_EMBEDDED_WORKER"] == "false"
    assert active["DATABASE__DRIVER"] == "postgres"