"""顺势加仓（滚仓）：纯计算。人工触发；止盈锁定首仓；程序监控触价市价成交。"""
from __future__ import annotations

from typing import Any, Optional, Tuple

from fib_key_monitor_lib import calc_fib_plan, fib_invalidate_by_mark

ROLL_MAX_LEGS_LONG = 3
ROLL_MAX_LEGS_SHORT = 3

MARKET_MODE = "market"
FIB_MODES = frozenset({"fib_618", "fib_786"})
BREAKOUT_MODE = "breakout"

MODE_LABELS = {
    MARKET_MODE: "市价加仓",
    "fib_618": "斐波0.618",
    "fib_786": "斐波0.786",
    BREAKOUT_MODE: "突破加仓",
}


def fib_ratio_from_mode(mode: str) -> Optional[float]:
    m = (mode or "").strip().lower()
    if m in ("fib_618", "618", "0.618"):
        return 0.618
    if m in ("fib_786", "786", "0.786"):
        return 0.786
    return None


def mode_label(mode: str) -> str:
    m = (mode or MARKET_MODE).strip().lower()
    return MODE_LABELS.get(m, m)


def fib_limit_entry(direction: str, upper: float, lower: float, mode: str) -> Tuple[Optional[float], Optional[str]]:
    """H/L 仅用于计算限价加仓价；多：下沿=止损侧；空：上沿=止损侧。"""
    ratio = fib_ratio_from_mode(mode)
    if ratio is None:
        return None, "斐波档位无效"
    h, l = float(upper), float(lower)
    if h <= l:
        return None, "上沿须大于下沿"
    direction = (direction or "long").strip().lower()
    if direction == "short":
        plan = calc_fib_plan("short", h, l, ratio)
    else:
        plan = calc_fib_plan("long", h, l, ratio)
    if not plan:
        return None, "无法计算斐波限价"
    entry, _sl, _tp = plan
    return float(entry), None


def max_roll_legs(direction: str) -> int:
    return ROLL_MAX_LEGS_LONG if (direction or "long").strip().lower() == "long" else ROLL_MAX_LEGS_SHORT


def avg_entry_after_add(
    qty_existing: float,
    entry_existing: float,
    add_qty: float,
    add_price: float,
) -> float:
    q1 = float(qty_existing)
    e1 = float(entry_existing)
    q2 = float(add_qty)
    e2 = float(add_price)
    total = q1 + q2
    if total <= 0:
        return 0.0
    return (q1 * e1 + q2 * e2) / total


def calc_risk_budget_usdt(capital_base_usdt: float, risk_percent: float) -> float:
    return float(capital_base_usdt) * (float(risk_percent) / 100.0)


def solve_add_amount_for_total_risk(
    direction: str,
    qty_existing: float,
    entry_existing: float,
    add_price: float,
    new_stop: float,
    risk_budget_usdt: float,
    contract_size: float = 1.0,
) -> Tuple[Optional[float], Optional[str]]:
    """
    合并持仓打到 new_stop 时总亏损 ≈ risk_budget（方案 C）。
    long:  (avg - SL) * (Q1+Q2) * cs = B  => Q2 = (B/cs - Q1*(E1-SL)) / (E2-SL)
    short: (SL - avg) * (Q1+Q2) * cs = B  => Q2 = (B/cs - Q1*(SL-E1)) / (SL-E2)
    """
    try:
        q1 = float(qty_existing)
        e1 = float(entry_existing)
        e2 = float(add_price)
        sl = float(new_stop)
        b = float(risk_budget_usdt)
        cs = float(contract_size) if contract_size else 1.0
    except (TypeError, ValueError):
        return None, "参数格式错误"
    if q1 <= 0 or e1 <= 0 or e2 <= 0 or b <= 0 or cs <= 0:
        return None, "持仓或风险预算无效"
    direction = (direction or "long").strip().lower()
    if direction == "short":
        denom = sl - e2
        numer = b / cs - q1 * (sl - e1)
        if denom <= 0:
            return None, "做空：新止损须高于加仓价"
    else:
        denom = e2 - sl
        numer = b / cs - q1 * (e1 - sl)
        if denom <= 0:
            return None, "做多：新止损须低于加仓价"
    q2 = numer / denom
    if q2 <= 0:
        return None, "按当前新止损与风险预算，无需加仓或无法再加（已满足风险上限）"
    return q2, None


def loss_at_stop_usdt(
    direction: str,
    avg: float,
    qty: float,
    stop: float,
    contract_size: float = 1.0,
) -> float:
    cs = float(contract_size or 1.0)
    direction = (direction or "long").strip().lower()
    if direction == "short":
        return (float(stop) - float(avg)) * float(qty) * cs
    return (float(avg) - float(stop)) * float(qty) * cs


def reward_at_tp_usdt(
    direction: str,
    avg: float,
    take_profit: float,
    qty: float,
    contract_size: float = 1.0,
) -> float:
    cs = float(contract_size or 1.0)
    direction = (direction or "long").strip().lower()
    if direction == "short":
        return (float(avg) - float(take_profit)) * float(qty) * cs
    return (float(take_profit) - float(avg)) * float(qty) * cs


def roll_fib_trigger_crossed(
    direction: str,
    prev_mark: Optional[float],
    mark: float,
    limit_price: float,
) -> bool:
    """斐波：多=向下穿越限价；空=向上穿越限价。"""
    try:
        m = float(mark)
        lv = float(limit_price)
        pm = float(prev_mark) if prev_mark is not None else None
    except (TypeError, ValueError):
        return False
    direction = (direction or "long").strip().lower()
    if direction == "long":
        if pm is None:
            return m <= lv
        return pm > lv and m <= lv
    if pm is None:
        return m >= lv
    return pm < lv and m >= lv


def roll_breakout_trigger_crossed(
    direction: str,
    prev_mark: Optional[float],
    mark: float,
    breakthrough_price: float,
) -> bool:
    """突破：多=向上穿越突破价；空=向下穿越突破价。"""
    try:
        m = float(mark)
        bp = float(breakthrough_price)
        pm = float(prev_mark) if prev_mark is not None else None
    except (TypeError, ValueError):
        return False
    direction = (direction or "long").strip().lower()
    if direction == "long":
        if pm is None:
            return m > bp
        return pm <= bp and m > bp
    if pm is None:
        return m < bp
    return pm >= bp and m < bp


def roll_fib_invalidate(direction: str, mark: float, upper: float, lower: float) -> bool:
    """斐波 pending 失效：止盈侧突破（多 mark>=H；空 mark<=L）。"""
    return fib_invalidate_by_mark(direction, mark, upper, lower)


def roll_breakout_invalidate(direction: str, mark: float, stop_loss: float) -> bool:
    """突破 pending 失效：未到突破价先触达止损侧（多 mark<=S；空 mark>=S）。"""
    try:
        m = float(mark)
        sl = float(stop_loss)
    except (TypeError, ValueError):
        return False
    direction = (direction or "long").strip().lower()
    if direction == "long":
        return m <= sl
    return m >= sl


def validate_roll_geometry(
    direction: str,
    add_mode: str,
    *,
    new_stop_loss: float,
    add_price: Optional[float] = None,
    fib_upper: Optional[float] = None,
    fib_lower: Optional[float] = None,
    breakthrough_price: Optional[float] = None,
    entry_existing: float = 0.0,
    initial_take_profit: float = 0.0,
    mark_price: Optional[float] = None,
) -> Optional[str]:
    direction = (direction or "long").strip().lower()
    mode = (add_mode or MARKET_MODE).strip().lower()
    try:
        sl = float(new_stop_loss)
        tp = float(initial_take_profit)
        e1 = float(entry_existing or 0)
    except (TypeError, ValueError):
        return "止损/止盈格式错误"
    if sl <= 0 or tp <= 0:
        return "止损与首仓止盈须大于0"
    if direction == "long":
        if e1 > 0 and tp <= e1:
            return "做多：首仓止盈须高于当前持仓均价"
    else:
        if e1 > 0 and tp >= e1:
            return "做空：首仓止盈须低于当前持仓均价"

    if mode == MARKET_MODE:
        if add_price is None or float(add_price) <= 0:
            return "市价加仓需要有效参考价"
        entry_add = float(add_price)
    elif mode in FIB_MODES:
        if fib_upper is None or fib_lower is None:
            return "斐波须填写上沿 H 与下沿 L"
        entry_add, err = fib_limit_entry(direction, float(fib_upper), float(fib_lower), mode)
        if err:
            return err
        if entry_add is None or entry_add <= 0:
            return "无法计算斐波限价"
    elif mode == BREAKOUT_MODE:
        if breakthrough_price is None:
            return "突破加仓须填写突破价"
        try:
            bp = float(breakthrough_price)
        except (TypeError, ValueError):
            return "突破价格式错误"
        if bp <= 0:
            return "突破价须大于0"
        entry_add = bp
        if direction == "long":
            if sl >= bp:
                return "做多：止损须低于突破价"
            if mark_price is not None and float(mark_price) >= bp:
                return "做多：当前价须低于突破价（等待向上突破）"
        else:
            if sl <= bp:
                return "做空：止损须高于突破价"
            if mark_price is not None and float(mark_price) <= bp:
                return "做空：当前价须高于突破价（等待向下跌破）"
    else:
        return "加仓方式无效"

    if mode != BREAKOUT_MODE:
        entry_add = float(entry_add)  # type: ignore[arg-type]
        if direction == "long":
            if sl >= entry_add:
                return "做多：新止损须低于加仓价"
        else:
            if sl <= entry_add:
                return "做空：新止损须高于加仓价"
    return None


def preview_roll(
    *,
    direction: str,
    symbol: str,
    qty_existing: float,
    entry_existing: float,
    initial_take_profit: float,
    add_mode: str,
    new_stop_loss: Optional[float] = None,
    risk_percent: float,
    capital_base_usdt: float,
    add_price: Optional[float] = None,
    fib_upper: Optional[float] = None,
    fib_lower: Optional[float] = None,
    breakthrough_price: Optional[float] = None,
    legs_done: int = 0,
    contract_size: float = 1.0,
) -> Tuple[Optional[dict[str, Any]], Optional[str]]:
    direction = (direction or "long").strip().lower()
    if legs_done >= max_roll_legs(direction):
        return None, f"{'做多' if direction == 'long' else '做空'}滚仓已达 {max_roll_legs(direction)} 次上限"
    mode = (add_mode or MARKET_MODE).strip().lower()
    if new_stop_loss is None:
        return None, "请填写新止损价"
    try:
        sl = float(new_stop_loss)
    except (TypeError, ValueError):
        return None, "止损价格式错误"
    if sl <= 0:
        return None, "止损须大于0"

    geom_err = validate_roll_geometry(
        direction,
        mode,
        new_stop_loss=sl,
        add_price=add_price,
        fib_upper=fib_upper,
        fib_lower=fib_lower,
        breakthrough_price=breakthrough_price,
        entry_existing=entry_existing,
        initial_take_profit=initial_take_profit,
        mark_price=add_price if mode == BREAKOUT_MODE else add_price,
    )
    if geom_err:
        return None, geom_err

    if mode == MARKET_MODE:
        entry_add = float(add_price)  # validated
    elif mode in FIB_MODES:
        entry_add, _ = fib_limit_entry(direction, float(fib_upper), float(fib_lower), mode)
        entry_add = float(entry_add or 0)
    else:
        entry_add = float(breakthrough_price or 0)

    risk_budget = calc_risk_budget_usdt(capital_base_usdt, risk_percent)
    q2_raw, err = solve_add_amount_for_total_risk(
        direction,
        qty_existing,
        entry_existing,
        entry_add,
        sl,
        risk_budget,
        contract_size,
    )
    if err:
        return None, err
    q2 = float(q2_raw)
    new_qty = qty_existing + q2
    new_avg = avg_entry_after_add(qty_existing, entry_existing, q2, entry_add)
    cs = float(contract_size or 1.0)
    loss_sl = loss_at_stop_usdt(direction, new_avg, new_qty, sl, cs)
    reward_tp = reward_at_tp_usdt(direction, new_avg, initial_take_profit, new_qty, cs)
    return {
        "symbol": symbol,
        "direction": direction,
        "add_mode": mode,
        "add_mode_label": mode_label(mode),
        "add_price": round(entry_add, 10),
        "new_stop_loss": round(sl, 10),
        "breakthrough_price": float(breakthrough_price) if breakthrough_price not in (None, "") else None,
        "initial_take_profit": float(initial_take_profit),
        "risk_percent": float(risk_percent),
        "risk_budget_usdt": round(risk_budget, 4),
        "add_amount_raw": q2,
        "qty_existing": float(qty_existing),
        "entry_existing": float(entry_existing),
        "qty_after": new_qty,
        "avg_entry_after": round(new_avg, 10),
        "loss_at_sl_usdt": round(loss_sl, 4),
        "reward_at_tp_usdt": round(reward_tp, 4),
        "legs_done": int(legs_done),
        "leg_index_next": int(legs_done) + 1,
        "fib_upper": fib_upper,
        "fib_lower": fib_lower,
        "contract_size": cs,
    }, None