import base64
import json
import logging
import os

import httpx

log = logging.getLogger("forgemcp")

DEFAULT_BASE_URL = "https://forge.mql5.io"
DEFAULT_TIMEOUT = 30

_CONFIG_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), "config.json")

_client = None


def load_config():
    if not os.path.exists(_CONFIG_PATH):
        return {}
    with open(_CONFIG_PATH, "r") as f:
        return json.load(f)


def get_client():
    """Return a singleton authenticated httpx client for the Algo Forge API."""
    global _client
    if _client is not None:
        return _client

    config = load_config()
    base_url = config.get("base_url") or DEFAULT_BASE_URL
    token = config.get("token") or os.environ.get("FORGE_TOKEN")
    timeout = config.get("timeout") or DEFAULT_TIMEOUT

    if not token:
        log.warning("No Algo Forge token configured (config.json or FORGE_TOKEN).")

    headers = {"Accept": "application/json"}
    if token:
        headers["Authorization"] = f"token {token}"

    _client = httpx.Client(
        base_url=f"{base_url.rstrip('/')}/api/v1",
        headers=headers,
        timeout=timeout,
    )
    return _client


def request(method, path, **kwargs):
    """Make an API call and normalize the result into a dict or list.

    Returns parsed JSON on success, or {"error": "..."} on any failure.
    """
    try:
        resp = get_client().request(method, path, **kwargs)
    except httpx.RequestError as exc:
        return {"error": f"Connection to Algo Forge failed: {exc}"}

    if resp.status_code == 204:
        return {"ok": True}

    if resp.status_code >= 400:
        return {"error": _error_message(resp)}

    if not resp.content:
        return {"ok": True}

    try:
        return resp.json()
    except ValueError:
        return {"error": "Algo Forge returned a non-JSON response."}


def _error_message(resp):
    """Extract a human-readable error from a Forgejo error response."""
    try:
        body = resp.json()
        msg = body.get("message") or body.get("error") or str(body)
    except ValueError:
        msg = resp.text or "unknown error"
    return f"HTTP {resp.status_code}: {msg}"


def encode_content(text):
    """Base64-encode file text for the contents API."""
    return base64.b64encode(text.encode("utf-8")).decode("ascii")


def decode_content(b64):
    """Decode base64 file content returned by the contents API."""
    return base64.b64decode(b64).decode("utf-8", errors="replace")