#!/usr/bin/env python3
"""Generate a compact OpenAPI spec from Drogon HttpController route macros."""

from __future__ import annotations

import argparse
import json
import re
from pathlib import Path


ROUTE_RE = re.compile(
    r"ADD_METHOD_TO\(\s*([A-Za-z_]\w*)::([A-Za-z_]\w*)\s*,\s*"
    r'"([^"]+)"\s*,\s*drogon::([A-Za-z]+)\s*\)',
    re.MULTILINE,
)


METHODS_WITH_JSON_BODY = {"post", "put", "patch"}
PUBLIC_OPERATIONS = {
    "health",
    "ready",
    "openApi",
    "docs",
    "registerCitizen",
    "requestOtp",
    "verifyOtp",
    "loginWithPassword",
}


def controller_tag(controller: str) -> str:
    return controller.removesuffix("Controller")


def openapi_path(path: str) -> tuple[str, list[dict]]:
    parameters: list[dict] = []

    def replace(match: re.Match[str]) -> str:
        name = "id" if match.group(1) == "1" else f"param{match.group(1)}"
        parameters.append(
            {
                "name": name,
                "in": "path",
                "required": True,
                "schema": {"type": "integer", "format": "int64"},
            }
        )
        return "{" + name + "}"

    return re.sub(r"\{(\d+)\}", replace, path), parameters


def request_body(path: str, method: str) -> dict | None:
    if method != "post" and method != "patch":
        return None
    if path.endswith("/media") or path.endswith("/photos"):
        return {
            "required": True,
            "content": {
                "multipart/form-data": {
                    "schema": {
                        "type": "object",
                        "properties": {
                            "files": {
                                "type": "array",
                                "items": {"type": "string", "format": "binary"},
                            }
                        },
                    }
                }
            },
        }
    if method in METHODS_WITH_JSON_BODY:
        return {
            "required": True,
            "content": {
                "application/json": {"schema": {"type": "object"}}
            },
        }
    return None


def operation(controller: str, handler: str, raw_path: str, method: str) -> dict:
    path, params = openapi_path(raw_path)
    op = {
        "tags": [controller_tag(controller)],
        "operationId": f"{controller}.{handler}",
        "parameters": params,
        "responses": {
            "200": {
                "description": "JSON response",
                "content": {"application/json": {"schema": {"type": "object"}}},
            }
        },
    }
    body = request_body(path, method)
    if body:
        op["requestBody"] = body
    if handler not in PUBLIC_OPERATIONS:
        op["security"] = [{"bearerAuth": []}]
    if method == "post":
        op["responses"]["201"] = op["responses"]["200"]
    return path, op


def generate(controllers_dir: Path, title: str, version: str) -> dict:
    spec = {
        "openapi": "3.0.3",
        "info": {
            "title": title,
            "version": version,
            "description": "Generated from Drogon controller route macros.",
        },
        "servers": [{"url": "http://localhost:5555"}],
        "components": {
            "securitySchemes": {
                "bearerAuth": {"type": "http", "scheme": "bearer"}
            }
        },
        "paths": {},
    }
    for header in sorted(controllers_dir.glob("*.h")):
        text = header.read_text(encoding="utf-8")
        for controller, handler, raw_path, drogon_method in ROUTE_RE.findall(text):
            method = drogon_method.lower()
            path, op = operation(controller, handler, raw_path, method)
            spec["paths"].setdefault(path, {})[method] = op
    return spec


def main() -> None:
    parser = argparse.ArgumentParser()
    parser.add_argument("--controllers", type=Path, required=True)
    parser.add_argument("--out", type=Path, required=True)
    parser.add_argument("--title", default="Visione API")
    parser.add_argument("--version", default="0.1.0")
    args = parser.parse_args()

    spec = generate(args.controllers, args.title, args.version)
    args.out.parent.mkdir(parents=True, exist_ok=True)
    args.out.write_text(json.dumps(spec, indent=2, sort_keys=True) + "\n",
                        encoding="utf-8")


if __name__ == "__main__":
    main()