"""tester.ini generator (doc 07 §2b).

A small INI tells the tester *what* to run: expert, symbol, period, tick
model, date range, deposit, leverage, report name, and ``ShutdownTerminal=1``
so the terminal closes itself when done (the bridge then knows it's finished).
"""
from __future__ import annotations

import configparser
from dataclasses import dataclass
from pathlib import Path
from typing import Optional

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

# Tick models (doc 07 §2b):
#   0 = Every tick based on real ticks (highest accuracy, slowest)
#   1 = Every tick (generated from M1)
#   2 = 1-minute OHLC (good for non-tick-sensitive, fast) — routine verification
#   4 = Open prices only (rough, fastest)
MODEL_OHLC = 2
MODEL_EVERY_TICK = 1
MODEL_REAL_TICKS = 0
MODEL_OPEN_PRICES = 4


@dataclass
class TesterConfig:
    """Inputs for one tester run (doc 07 §2b).

    ``FromDate`` / ``ToDate`` are formatted ``YYYY.MM.DD`` for MT5. The login
    section lives separately (kept out of code via the env file, doc 07 §5).
    """

    expert: str                      # e.g. "Experts\\MyEA.ex5"
    symbol: str
    period: str = "H1"               # chart timeframe (≤ the EA's signal timeframe)
    model: int = MODEL_OHLC          # tick model
    from_date: str = "2024.01.01"     # YYYY.MM.DD
    to_date: str = "2026.01.01"
    deposit: float = 10000.0
    leverage: int = 100
    report: str = "report_myrun"     # output HTML name (no extension)
    shutdown_terminal: bool = True
    set_file: Optional[str] = None   # path to the .set, or None to inline
    login: Optional[int] = None      # from env, never hard-coded
    password: Optional[str] = None   # from env, never hard-coded
    server: Optional[str] = None     # broker server


def write_tester_ini(cfg: TesterConfig, path: str | Path) -> str:
    """Write a ``tester.ini`` for ``terminal64.exe /config:`` and return its path."""
    p = Path(path)
    p.parent.mkdir(parents=True, exist_ok=True)
    cp = configparser.ConfigParser()
    cp.optionxform = str  # preserve case (MT5 keys are case-sensitive)
    cp["Tester"] = {
        "Expert": cfg.expert,
        "Symbol": cfg.symbol,
        "Period": cfg.period,
        "Model": str(cfg.model),
        "FromDate": cfg.from_date,
        "ToDate": cfg.to_date,
        "Deposit": str(cfg.deposit),
        "Leverage": str(cfg.leverage),
        "Report": cfg.report,
        "ShutdownTerminal": "1" if cfg.shutdown_terminal else "0",
    }
    if cfg.set_file:
        cp["Tester"]["TestReplaceExpert"] = "0"
    common: dict[str, str] = {}
    if cfg.login is not None:
        common["Login"] = str(cfg.login)
    if cfg.password is not None:
        common["Password"] = cfg.password
    if cfg.server is not None:
        common["Server"] = cfg.server
    if common:
        cp["Common"] = common
    with p.open("w", encoding="utf-8") as f:
        cp.write(f)
    return str(p)