#!/usr/bin/env python3
"""Validate that a 1C change proposal stays within the read-only/extension-first safety contract."""

from __future__ import annotations

import argparse
import json
from pathlib import Path
from typing import Any


FORBIDDEN_PATH_PARTS = {
    "config",
    "configsave",
    "configcas",
}


def load_json(path: Path) -> dict[str, Any]:
    return json.loads(path.read_text(encoding="utf-8-sig"))


def issue(severity: str, code: str, message: str, *, target: dict[str, Any] | None = None) -> dict[str, Any]:
    result = {"severity": severity, "code": code, "message": message}
    if target:
        result["target"] = target
    return result


def path_text(target: dict[str, Any]) -> str:
    return str(target.get("path") or target.get("module_path") or "")


def normalized_path_parts(path: str) -> list[str]:
    return [part.casefold() for part in path.replace("/", "\\").split("\\") if part]


def is_extension_origin(target: dict[str, Any], preferred_extension: str | None) -> bool:
    origin = target.get("origin") or {}
    if origin.get("layer") != "extension":
        return False
    if preferred_extension and origin.get("extension") != preferred_extension:
        return False
    return True


def is_extension_path(path: str, preferred_extension: str | None) -> bool:
    parts = normalized_path_parts(path)
    if "расширения" not in parts and "extensions" not in parts:
        return False
    if preferred_extension:
        lowered = preferred_extension.casefold()
        return lowered in parts
    return True


def forbidden_path_reason(path: str) -> str | None:
    parts = normalized_path_parts(path)
    for part in parts:
        if part in FORBIDDEN_PATH_PARTS:
            return part
    if path.startswith("_") or "\\_" in path:
        return "sql_physical_name_like_path"
    return None


def check_target_exists(target: dict[str, Any]) -> list[dict[str, Any]]:
    findings = []
    path = path_text(target)
    if not path:
        findings.append(issue("error", "missing_path", "Target has no path.", target=target))
        return findings
    if not Path(path).exists():
        findings.append(issue("error", "path_not_found", f"Target path does not exist: {path}", target=target))
    line = target.get("line")
    if line:
        try:
            line_int = int(line)
            if line_int < 1:
                findings.append(issue("error", "invalid_line", f"Invalid target line: {line}", target=target))
        except (TypeError, ValueError):
            findings.append(issue("error", "invalid_line", f"Invalid target line: {line}", target=target))
    return findings


def check_write_candidate(target: dict[str, Any], preferred_extension: str | None) -> list[dict[str, Any]]:
    findings = []
    path = path_text(target)
    findings.extend(check_target_exists(target))
    if not is_extension_origin(target, preferred_extension):
        findings.append(issue("error", "write_candidate_not_preferred_extension_origin", "Write candidate is not in the preferred extension origin.", target=target))
    if not is_extension_path(path, preferred_extension):
        findings.append(issue("error", "write_candidate_not_preferred_extension_path", "Write candidate path is not inside the preferred extension directory.", target=target))
    forbidden = forbidden_path_reason(path)
    if forbidden:
        findings.append(issue("error", "forbidden_write_path", f"Write candidate path is forbidden: {forbidden}", target=target))
    if target.get("kind") not in {"bsl_module", "form_xml"}:
        findings.append(issue("warning", "unusual_write_candidate_kind", f"Unexpected write candidate kind: {target.get('kind')}", target=target))
    return findings


def check_reference_target(target: dict[str, Any]) -> list[dict[str, Any]]:
    findings = check_target_exists(target)
    forbidden = forbidden_path_reason(path_text(target))
    if forbidden:
        findings.append(issue("warning", "forbidden_reference_path", f"Reference path is forbidden for writes and must remain read-only: {forbidden}", target=target))
    return findings


def check_proposal(proposal: dict[str, Any]) -> dict[str, Any]:
    findings = []
    strategy = proposal.get("write_strategy") or {}
    preferred_extension = strategy.get("preferred_extension")
    if strategy.get("mode") != "extension_first_proposal":
        findings.append(issue("error", "unsupported_write_strategy", f"Unsupported write strategy: {strategy.get('mode')}"))
    if not preferred_extension:
        findings.append(issue("warning", "missing_preferred_extension", "No preferred extension selected; patch generation should create/choose an extension explicitly."))

    policy = proposal.get("target_policy") or {}
    write_candidates = policy.get("write_candidates") or []
    references = policy.get("read_only_reference_files") or []
    if not write_candidates:
        findings.append(issue("warning", "no_write_candidates", "No write candidates were selected."))
    for target in write_candidates:
        findings.extend(check_write_candidate(target, preferred_extension))
    for target in references:
        findings.extend(check_reference_target(target))

    forbidden = set(strategy.get("forbidden") or [])
    required_forbidden = {
        "direct SQL metadata/data updates",
        "direct Config/ConfigSave/ConfigCAS writes",
        "automatic production Designer update/apply",
    }
    missing = sorted(required_forbidden - forbidden)
    if missing:
        findings.append(issue("error", "missing_forbidden_strategy_items", "Write strategy is missing forbidden items: " + ", ".join(missing)))

    errors = [row for row in findings if row.get("severity") == "error"]
    warnings = [row for row in findings if row.get("severity") == "warning"]
    return {
        "object": proposal.get("object"),
        "preferred_extension": preferred_extension,
        "passed": not errors,
        "findings": findings,
        "counts": {
            "errors": len(errors),
            "warnings": len(warnings),
            "write_candidates": len(write_candidates),
            "read_only_references": len(references),
        },
    }


def check(data: dict[str, Any]) -> dict[str, Any]:
    proposal_checks = [check_proposal(proposal) for proposal in data.get("proposals") or []]
    errors = sum(item.get("counts", {}).get("errors", 0) for item in proposal_checks)
    warnings = sum(item.get("counts", {}).get("warnings", 0) for item in proposal_checks)
    return {
        "schema": "onec_change_proposal_safety_check.v1",
        "source_schema": data.get("schema"),
        "task": data.get("task"),
        "passed": errors == 0,
        "proposal_checks": proposal_checks,
        "required_gates_before_real_write": [
            "backup_gate",
            "round_trip_parser_gate",
            "designer_validation_gate",
            "saved_state_gate",
            "extension_packaging_gate",
            "diff_gate",
            "minimal_write_scope_gate",
            "recovery_test_gate",
        ],
        "counts": {
            "proposals": len(proposal_checks),
            "errors": errors,
            "warnings": warnings,
        },
    }


def main() -> int:
    parser = argparse.ArgumentParser(description="Check 1C proposal safety.")
    parser.add_argument("--proposal", type=Path, required=True)
    parser.add_argument("--output", type=Path)
    args = parser.parse_args()

    result = check(load_json(args.proposal))
    output = json.dumps(result, ensure_ascii=False, indent=2) + "\n"
    if args.output:
        args.output.parent.mkdir(parents=True, exist_ok=True)
        args.output.write_text(output, encoding="utf-8")
        print(json.dumps({"output": str(args.output), "passed": result["passed"], "counts": result["counts"]}, ensure_ascii=False))
    else:
        print(output)
    return 0 if result["passed"] else 2


if __name__ == "__main__":
    raise SystemExit(main())