#!/usr/bin/env python3
"""Figure ch04 — Indice des prix des logements neufs (IPLN), total maison et terrain, déc. 2016 = 100, janvier 2010 → septembre 2026 :
Montréal, Québec, Gatineau (partie du Québec), Sherbrooke, Trois-Rivières, Canada. DONNÉES RÉELLES : Statistique Canada, tableau 18-10-0205-01.
Sortie : assets/figures/ch04/ch04-fig-ipln-rmr.pdf"""
import sys, pathlib
ROOT = pathlib.Path(__file__).resolve().parents[3]
sys.path.insert(0, str(ROOT / "analysis/python")); sys.path.insert(0, str(ROOT / "analysis/python/cases"))
import pandas as pd, matplotlib.pyplot as plt, matplotlib.dates as mdates
from traite.style import setup, palette, savefig, LARGEUR
import ch04_marches as cas

ORDRE = ["Montréal", "Québec", "Gatineau (partie du Québec)", "Sherbrooke", "Trois-Rivières", "Canada"]

def main():
    setup()
    df = cas.ipln(); df = df[(df["composante"] == "Total") & (df["date"] >= "2010-01-01")]
    fig, ax = plt.subplots(figsize=(LARGEUR, 3.6))
    for i, geo in enumerate(ORDRE):
        s = df[df["geo"] == geo]
        ls = "--" if geo == "Canada" else "-"; lw = 2.0 if geo == "Montréal" else 1.4
        ax.plot(s["date"], s["indice"], color=palette.cat[i], ls=ls, lw=lw, label=geo.replace(" (partie du Québec)", " (partie QC)"))
        dy = {"Canada": 2.6, "Trois-Rivières": 0.4, "Gatineau (partie du Québec)": -2.2}.get(geo, 0.0)
        ax.text(s["date"].iloc[-1] + pd.Timedelta(days=60), s["indice"].iloc[-1] + dy, f"{s['indice'].iloc[-1]:.1f}".replace(".", ","), fontsize=7, va="center", color=palette.ink)
    ax.axhline(100, color=palette.ink2, lw=0.6, ls=":"); ax.text(pd.Timestamp("2010-02-01"), 101.5, "déc. 2016 = 100", fontsize=7.5, color=palette.ink2)
    ax.axvspan(pd.Timestamp("2020-03-01"), pd.Timestamp("2022-12-31"), color=palette.grid, alpha=0.5, lw=0)
    ax.text(pd.Timestamp("2020-04-15"), 72, "mars 2020 –\ndéc. 2022", fontsize=7, color=palette.ink2)
    ax.set_ylabel("Indice (déc. 2016 = 100)"); ax.set_xlim(pd.Timestamp("2010-01-01"), pd.Timestamp("2027-06-01")); ax.set_ylim(70, 170)
    ax.xaxis.set_major_locator(mdates.YearLocator(2)); ax.xaxis.set_major_formatter(mdates.DateFormatter("%Y"))
    ax.legend(loc="upper left", ncol=2, fontsize=7.5)
    out = savefig(fig, "ch04/ch04-fig-ipln-rmr.pdf"); print("OK", out)

if __name__ == "__main__":
    main()