#!/usr/bin/env python3
"""Syncs authoritative bo-*.set preset values into MT5's actual live-session
cache files (MQL5/Profiles/Charts/Default/chartNN.chr).

Root cause (found 2026-08-10): MT5's "save chart state on graceful exit"
never actually fires under this Wine/container setup -- chartNN.chr files
were found frozen at their 2026-08-06 23:26 mtimes despite many later
restarts, including ones using the documented `stop_grace_period: 60s` +
`docker compose down` "graceful" path. Every restart since Aug 6 silently
reloads that one frozen snapshot, which is why a live GUI input edit
(Properties/F7 -> OK) reverts after the next restart no matter how
"gracefully" the container is stopped. This hit the XAUUSD spread filter
(Jul 30, Aug 6/7) and the Monday A/B reversion (Aug 10) alike -- general,
not symbol-specific.

Fix: don't rely on MT5 ever writing this file correctly. Treat the
bo-*.set files (repo + Presets/) as the single source of truth and write
them directly into chartNN.chr ourselves, every boot. chartNN.chr uses
the exact same `Key=Value` input names as the .set files (verified), just
UTF-16LE with a BOM and CRLF instead of the .set files' UTF-8/LF -- and
one chart file per open chart, auto-mapped here via each file's own
`symbol=` line rather than a hardcoded chart-number list, so this keeps
working if charts are ever reordered.

Idempotent -- safe to run any time, not just at boot.
"""
import glob
import os
import re
import sys

PRESETS_DIR = "/config/.wine/drive_c/Program Files/MetaTrader 5/MQL5/Presets"
CHARTS_DIR = "/config/.wine/drive_c/Program Files/MetaTrader 5/MQL5/Profiles/Charts/Default"

BOM = b"\xff\xfe"


def load_preset(path):
    values = {}
    with open(path, "r", encoding="utf-8", errors="ignore") as f:
        for line in f:
            line = line.strip("\r\n")
            if not line or line.startswith(";") or line.startswith("#"):
                continue
            if "=" not in line:
                continue
            key, _, value = line.partition("=")
            values[key] = value
    return values


def sync_chart(chart_path):
    with open(chart_path, "rb") as f:
        raw = f.read()

    if not raw.startswith(BOM):
        return None, "no UTF-16LE BOM, skipping"

    text = raw[len(BOM):].decode("utf-16-le", errors="replace")

    m = re.search(r"^symbol=(\S+)\r?$", text, re.MULTILINE)
    if not m:
        return None, "no symbol= line found"
    symbol = m.group(1)

    preset_path = os.path.join(PRESETS_DIR, f"bo-{symbol.lower()}.set")
    if not os.path.isfile(preset_path):
        return symbol, f"no matching preset {preset_path}"

    preset_values = load_preset(preset_path)

    lines = text.split("\n")
    changed = 0
    for i, line in enumerate(lines):
        body = line[:-1] if line.endswith("\r") else line
        if "=" not in body:
            continue
        key, _, current_value = body.partition("=")
        if key in preset_values and preset_values[key] != current_value:
            lines[i] = f"{key}={preset_values[key]}\r"
            changed += 1

    if changed:
        new_text = "\n".join(lines)
        new_raw = BOM + new_text.encode("utf-16-le")
        tmp_path = chart_path + ".tmp"
        with open(tmp_path, "wb") as f:
            f.write(new_raw)
        os.replace(tmp_path, chart_path)

    return symbol, f"{changed} value(s) synced from {os.path.basename(preset_path)}"


def main():
    if not os.path.isdir(CHARTS_DIR):
        print(f"No charts dir at {CHARTS_DIR} -- nothing to sync yet.")
        return 0

    for chart_path in sorted(glob.glob(os.path.join(CHARTS_DIR, "chart*.chr"))):
        symbol, msg = sync_chart(chart_path)
        label = f"[{symbol}]" if symbol else ""
        print(f"  {os.path.basename(chart_path)} {label}: {msg}")
    return 0


if __name__ == "__main__":
    sys.exit(main())