"""区间内 Volume Profile。"""
from __future__ import annotations

from typing import Any, Dict, List

import numpy as np
import pandas as pd


def compute_volume_profile(
	df: pd.DataFrame,
	start_idx: int,
	end_idx: int,
	bin_count: int = 50,
	value_area_pct: float = 0.70,
) -> Dict[str, Any]:
	seg = df.iloc[start_idx : end_idx + 1]
	if seg.empty:
		return {"bins": [], "poc": None, "vah": None, "val": None, "bin_count": bin_count}

	typical = (seg["high"].astype(float) + seg["low"].astype(float) + seg["close"].astype(float)) / 3.0
	vol = seg["volume"].astype(float).fillna(0.0)
	lo = float(seg["low"].min())
	hi = float(seg["high"].max())
	if not np.isfinite(lo) or not np.isfinite(hi) or hi <= lo:
		mid = float(seg["close"].iloc[-1])
		return {
			"bins": [{"price": mid, "volume": float(vol.sum())}],
			"poc": mid,
			"vah": mid,
			"val": mid,
			"bin_count": 1,
		}

	edges = np.linspace(lo, hi, bin_count + 1)
	# 右开最后一桶闭合
	idx = np.clip(np.digitize(typical.values, edges) - 1, 0, bin_count - 1)
	vols = np.zeros(bin_count, dtype=float)
	for i, v in zip(idx, vol.values):
		vols[i] += float(v)

	centers = (edges[:-1] + edges[1:]) / 2.0
	poc_i = int(np.argmax(vols)) if vols.sum() > 0 else bin_count // 2
	poc = float(centers[poc_i])

	# Value Area：从 POC 向两侧扩展直到累计 >= value_area_pct
	total = float(vols.sum()) or 1.0
	target = total * value_area_pct
	left = right = poc_i
	acc = float(vols[poc_i])
	while acc < target and (left > 0 or right < bin_count - 1):
		left_v = vols[left - 1] if left > 0 else -1.0
		right_v = vols[right + 1] if right < bin_count - 1 else -1.0
		if right_v >= left_v and right < bin_count - 1:
			right += 1
			acc += float(vols[right])
		elif left > 0:
			left -= 1
			acc += float(vols[left])
		else:
			break

	bins: List[Dict[str, float]] = [
		{"price": float(centers[i]), "volume": float(vols[i])} for i in range(bin_count)
	]
	return {
		"bins": bins,
		"poc": poc,
		"vah": float(centers[right]),
		"val": float(centers[left]),
		"bin_count": bin_count,
	}