"""Style graphique du traité (Matplotlib). Palette validée : styles/palette.json.
Usage :
    from traite.style import setup, palette, savefig, LARGEUR, DEMI
    setup(); fig, ax = plt.subplots(figsize=(LARGEUR, 3.2)); ... savefig(fig, "ch16/ch16-fig-x.pdf")"""
from __future__ import annotations
import json, pathlib
import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib import font_manager

ROOT = pathlib.Path(__file__).resolve().parents[3]
_P = json.loads((ROOT / "styles/palette.json").read_text())
LARGEUR = 135 / 25.4   # pouces (pleine largeur de texte)
DEMI = 65 / 25.4

class _Palette:
    cat = _P["categorical"]; seq = _P["sequential_blue"]; div = _P["diverging"]; status = _P["status"]
    surface = _P["surface"]; ink = _P["text_primary"]; ink2 = _P["text_secondary"]; grid = _P["grid"]
    brand = _P["brand_primary"]; brand2 = _P["brand_secondary"]
    @staticmethod
    def cmap_seq(): return mpl.colors.LinearSegmentedColormap.from_list("traite_seq", _P["sequential_blue"])
    @staticmethod
    def cmap_div(): d = _P["diverging"]; return mpl.colors.LinearSegmentedColormap.from_list("traite_div", [d["neg"], d["mid"], d["pos"]])
palette = _Palette()

def _register_fonts():
    import subprocess
    for name in ("SourceSans3-Regular.otf", "SourceSans3-Bold.otf", "SourceSans3-It.otf", "SourceSans3-Semibold.otf"):
        try:
            p = subprocess.run(["kpsewhich", name], capture_output=True, text=True, timeout=10).stdout.strip()
            if p: font_manager.fontManager.addfont(p)
        except Exception:
            pass

def setup():
    _register_fonts()
    fam = "Source Sans 3" if any(f.name == "Source Sans 3" for f in font_manager.fontManager.ttflist) else "DejaVu Sans"
    mpl.rcParams.update({
        "font.family": fam, "font.size": 8.5, "axes.titlesize": 9, "axes.labelsize": 8.5, "legend.fontsize": 8,
        "xtick.labelsize": 8, "ytick.labelsize": 8, "figure.facecolor": palette.surface, "axes.facecolor": palette.surface,
        "savefig.facecolor": palette.surface, "axes.edgecolor": palette.ink2, "axes.labelcolor": palette.ink,
        "xtick.color": palette.ink2, "ytick.color": palette.ink2, "text.color": palette.ink,
        "axes.spines.top": False, "axes.spines.right": False, "axes.grid": True, "grid.color": palette.grid,
        "grid.linewidth": 0.6, "axes.axisbelow": True, "lines.linewidth": 1.6, "lines.markersize": 5,
        "axes.prop_cycle": mpl.cycler(color=palette.cat), "legend.frameon": False, "figure.dpi": 150,
        "pdf.fonttype": 42, "axes.formatter.use_locale": False, "axes.unicode_minus": True,
    })

def fmt_dollars(x, pos=None):
    """Formate 452500 → « 452 500 $ » (espace fine insécable)."""
    s = f"{x:,.0f}".replace(",", " ")
    return f"{s} $"

def fmt_milliers(x, pos=None):
    return f"{x:,.0f}".replace(",", " ")

def fmt_pct(x, pos=None, dec=1):
    return (f"{x*100:.{dec}f}".replace(".", ",")) + " %"

def savefig(fig, rel_path: str, **kw):
    out = ROOT / "assets/figures" / rel_path
    out.parent.mkdir(parents=True, exist_ok=True)
    fig.savefig(out, bbox_inches="tight", **kw)
    plt.close(fig)
    return out