from __future__ import annotations

import base64
import io
import logging

from .candle_rows import rows_to_ohl

LOGGER = logging.getLogger("onchain_scout.chart_candles")


def daily_candles_png_base64(rows_1d: list[list[str]], symbol: str, max_bars: int = 48) -> str | None:
    """
    生成简易日线蜡烛图 PNG（base64，无 data URL 前缀），供 Ollama 多模态。
    若 matplotlib 不可用或失败则返回 None。
    """
    try:
        import matplotlib

        matplotlib.use("Agg")
        import matplotlib.pyplot as plt
        from matplotlib.patches import Rectangle
    except ImportError:
        LOGGER.warning("matplotlib not installed, skip chart image")
        return None

    o, h, l, c = rows_to_ohl(rows_1d)
    n = len(c)
    if n < 5:
        return None
    start = max(0, n - max_bars)
    o, h, l, c = o[start:], h[start:], l[start:], c[start:]
    x = list(range(len(c)))

    fig, ax = plt.subplots(figsize=(7, 3), facecolor="#030308")
    ax.set_facecolor("#050510")
    for i in x:
        up = c[i] >= o[i]
        col = "#00f5d4" if up else "#ff006e"
        ax.plot([i, i], [l[i], h[i]], color=col, linewidth=0.9, alpha=0.9)
        body_low = min(o[i], c[i])
        body_h = abs(c[i] - o[i])
        if body_h < 1e-12:
            body_h = (h[i] - l[i]) * 0.08 or 1e-8
        ax.add_patch(
            Rectangle(
                (i - 0.35, body_low),
                0.7,
                body_h,
                facecolor=col,
                edgecolor=col,
                linewidth=0.4,
                alpha=0.85,
            )
        )
    ax.set_title(f"{symbol} 1D", color="#00fff7", fontsize=11, fontfamily="monospace")
    ax.tick_params(colors="#7dffb3", labelsize=7)
    for spine in ax.spines.values():
        spine.set_color("#1b3d2f")
    ax.grid(True, alpha=0.12, color="#00fff7")
    plt.tight_layout()
    buf = io.BytesIO()
    fig.savefig(buf, format="png", dpi=100, facecolor=fig.get_facecolor())
    plt.close(fig)
    buf.seek(0)
    return base64.b64encode(buf.read()).decode("ascii")