"""Compile an EA from .mq5 to .ex5 with MetaEditor (doc 07 §1).

The tester runs a compiled ``.ex5``. Compile from the command line so the
bridge can do it programmatically. Custom indicators the EA calls must be
compiled too and placed in ``MQL5\\Indicators\\``. If the EA's ``#include``
files live in a non-standard folder, compile the terminal in portable mode
(``/portable``) so MetaEditor resolves includes from that terminal's
``MQL5\\Include\\``.
"""
from __future__ import annotations

import subprocess
from pathlib import Path

DEFAULT_MT5_INSTALL = r"C:\Program Files\MetaTrader 5 IC Markets Global"


def default_metaeditor_path(mt5_install: str = DEFAULT_MT5_INSTALL) -> str:
    """Return the metaeditor64.exe path for the given MT5 install."""
    return str(Path(mt5_install) / "metaeditor64.exe")


def compile_ea(
    mq5_path: str | Path,
    *,
    metaeditor_path: str | None = None,
    mt5_install: str = DEFAULT_MT5_INSTALL,
    timeout: int = 120,
) -> tuple[bool, str]:
    """Compile an ``.mq5`` EA to ``.ex5`` via MetaEditor's command line.

    Returns ``(success, log_text)``. MetaEditor writes a ``.log`` next to the
    source; on a clean compile the ``.ex5`` appears beside the ``.mq5``.

    Command line (doc 07 §1)::

        metaeditor64.exe /compile:"C:\\path\\to\\Expert.mq5" /log
    """
    mq5 = Path(mq5_path)
    if not mq5.exists():
        return False, f"source not found: {mq5}"
    editor = metaeditor_path or default_metaeditor_path(mt5_install)
    if not Path(editor).exists():
        return False, f"metaeditor not found: {editor}"

    cmd = [editor, f"/compile:{mq5}", "/log"]
    try:
        proc = subprocess.run(
            cmd, capture_output=True, text=True, timeout=timeout, check=False,
        )
        log_path = mq5.with_suffix(".log")
        log_text = proc.stdout + "\n" + proc.stderr
        if log_path.exists():
            try:
                log_text += "\n--- metaeditor log ---\n" + log_path.read_text(
                    encoding="utf-16-le", errors="replace"
                )
            except Exception:
                pass
        ex5 = mq5.with_suffix(".ex5")
        success = ex5.exists() and ex5.stat().st_size > 0
        return success, log_text
    except subprocess.TimeoutExpired:
        return False, f"compile timed out after {timeout}s"
    except FileNotFoundError as e:
        return False, f"failed to launch metaeditor: {e}"