import re
from pathlib import Path
from reportlab.lib.pagesizes import A4
from reportlab.lib.units import cm
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER, TA_LEFT
from reportlab.platypus import (BaseDocTemplate, PageTemplate, Frame,
                                Paragraph, Spacer, Table, TableStyle,
                                Image, HRFlowable, PageBreak, NextPageTemplate,
                                KeepTogether)
from reportlab.pdfgen import canvas as rl_canvas
from datetime import date

BASE = Path(__file__).parent

AUTORE   = "Ufficio Tecnico – Cevolani S.p.A."
VERSIONE = "1.0"
STATO    = "Definitivo"

# ─── Palette ──────────────────────────────────────────────────────────────────
C_DARK    = colors.HexColor("#0f2236")
C_BLUE    = colors.HexColor("#1a3a5c")
C_MID     = colors.HexColor("#2c5f8a")
C_LIGHT   = colors.HexColor("#4a8fc0")
C_ACCENT  = colors.HexColor("#e8f2fa")
C_GRAY    = colors.HexColor("#f6f7f8")
C_BORDER  = colors.HexColor("#b8c8d8")
C_TEXT    = colors.HexColor("#1e1e1e")
C_WHITE   = colors.white

W, H = A4
MARGIN = 2.5 * cm
CONTENT_W = W - 2 * MARGIN

# ─── TableStyle ───────────────────────────────────────────────────────────────
def make_table_style(header_color=None):
    hc = header_color or C_MID
    return TableStyle([
        ("BACKGROUND",     (0, 0), (-1, 0), hc),
        ("TEXTCOLOR",      (0, 0), (-1, 0), C_WHITE),
        ("FONTNAME",       (0, 0), (-1, 0), "Helvetica-Bold"),
        ("FONTSIZE",       (0, 0), (-1, 0), 9),
        ("ROWBACKGROUNDS", (0, 1), (-1, -1), [C_WHITE, C_GRAY]),
        ("FONTNAME",       (0, 1), (-1, -1), "Helvetica"),
        ("FONTSIZE",       (0, 1), (-1, -1), 9),
        ("GRID",           (0, 0), (-1, -1), 0.4, C_BORDER),
        ("TOPPADDING",     (0, 0), (-1, -1), 5),
        ("BOTTOMPADDING",  (0, 0), (-1, -1), 5),
        ("LEFTPADDING",    (0, 0), (-1, -1), 8),
        ("RIGHTPADDING",   (0, 0), (-1, -1), 8),
        ("VALIGN",         (0, 0), (-1, -1), "MIDDLE"),
    ])

TABLE_STD  = make_table_style()
TABLE_DARK = make_table_style(C_DARK)

COVER_INFO_STYLE = TableStyle([
    ("FONTNAME",      (0, 0), (-1, -1), "Helvetica"),
    ("FONTSIZE",      (0, 0), (-1, -1), 10),
    ("FONTNAME",      (0, 0), (0, -1),  "Helvetica-Bold"),
    ("TEXTCOLOR",     (0, 0), (0, -1),  C_BLUE),
    ("TEXTCOLOR",     (1, 0), (1, -1),  C_TEXT),
    ("ROWBACKGROUNDS",(0, 0), (-1, -1), [C_WHITE, C_GRAY]),
    ("GRID",          (0, 0), (-1, -1), 0.4, C_BORDER),
    ("TOPPADDING",    (0, 0), (-1, -1), 7),
    ("BOTTOMPADDING", (0, 0), (-1, -1), 7),
    ("LEFTPADDING",   (0, 0), (-1, -1), 12),
])


# ─── Parser markdown ──────────────────────────────────────────────────────────
def parse_md(md_path: Path) -> dict:
    text = md_path.read_text(encoding="utf-8")
    data = {}

    m = re.search(r"^# (.+)$", text, re.MULTILINE)
    data["nome"] = m.group(1).strip() if m else md_path.parent.name

    kv = dict(re.findall(r"^\| (.+?) \| (.+?) \|$", text, re.MULTILINE))
    kv = {k.strip(): v.strip() for k, v in kv.items() if k.strip() != "---"}

    data["t0"]       = kv.get("Inizio", "").replace(" s", "")
    data["t_end"]    = kv.get("Fine",   "").replace(" s", "")
    data["n_punti"]  = kv.get("Numero di punti", "")
    data["zona_exc"] = kv.get("Zona esclusa (peso = 0)", None)
    data["r2"]       = kv.get("R²", "")
    data["intervallo"] = f"{data['t0']} – {data['t_end']} s"

    m = re.search(r"\$\$(.+?)\$\$", text, re.DOTALL)
    data["equazione_latex"] = m.group(1).strip() if m else ""
    data["equazione"] = (data["equazione_latex"]
                         .replace(r"\cdot", "·").replace(r"\infty", "∞"))

    rows3 = re.findall(r"^\| (.+?) \| (.+?) \| (.+?) \|$", text, re.MULTILINE)
    params = {r[0].strip(): (r[1].strip(), r[2].strip())
              for r in rows3 if r[0].strip() not in ("Parametro", "---")}
    data["A"]       = params.get("A", ("", ""))[0].replace(" °C", "")
    data["A_err"]   = (params.get("A", ("", ""))[1]
                       .replace("± ", "").replace("+/- ", "").replace(" °C", ""))
    data["tau"]     = params.get("τ", ("", ""))[0].replace(" s", "")
    data["tau_err"] = (params.get("τ", ("", ""))[1]
                       .replace("± ", "").replace("+/- ", "").replace(" s", ""))

    pngs = sorted(md_path.parent.glob("*.png"))
    data["png"] = pngs[0] if pngs else None
    return data


def collect_induttori() -> list:
    return [parse_md(md)
            for folder in sorted(BASE.glob("induttore*/"))
            for md in sorted(folder.glob("report*.md"))]


# ─── Canvas con header/footer ─────────────────────────────────────────────────
class ProfessionalCanvas(rl_canvas.Canvas):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self._saved = []

    def showPage(self):
        self._saved.append(dict(self.__dict__))
        self._startPage()

    def save(self):
        n = len(self._saved)
        for state in self._saved:
            self.__dict__.update(state)
            if self._pageNumber > 1:
                self._draw_header()
            self._draw_footer(n)
            super().showPage()
        super().save()

    def _draw_header(self):
        self.saveState()
        # Barra colorata in cima
        self.setFillColor(C_DARK)
        self.rect(0, H - 1.4*cm, W, 1.4*cm, fill=1, stroke=0)
        self.setFillColor(C_LIGHT)
        self.rect(0, H - 1.4*cm, 0.5*cm, 1.4*cm, fill=1, stroke=0)
        self.setFillColor(C_WHITE)
        self.setFont("Helvetica-Bold", 9)
        self.drawString(0.8*cm, H - 0.9*cm, "ANALISI TERMICA FORNO")
        self.setFont("Helvetica", 8)
        self.drawRightString(W - 0.6*cm, H - 0.9*cm, "Cevolani S.p.A. — Uso interno")
        self.restoreState()

    def _draw_footer(self, total):
        self.saveState()
        self.setStrokeColor(C_MID)
        self.setLineWidth(0.8)
        self.line(MARGIN, 1.9*cm, W - MARGIN, 1.9*cm)
        self.setFillColor(C_BLUE)
        self.setFont("Helvetica", 7.5)
        self.drawString(MARGIN, 1.4*cm,
                        f"Documento: report_completo  |  Ver. {VERSIONE}  |  {STATO}")
        self.setFont("Helvetica-Bold", 8)
        self.drawRightString(W - MARGIN, 1.4*cm,
                             f"Pag. {self._pageNumber} / {total}")
        self.restoreState()


# ─── Stili testo ──────────────────────────────────────────────────────────────
def make_styles():
    styles = getSampleStyleSheet()
    s = {}
    s["body"] = ParagraphStyle("body", parent=styles["BodyText"],
                               fontSize=9.5, leading=14, textColor=C_TEXT,
                               spaceAfter=6)
    s["h1"] = ParagraphStyle("h1", fontName="Helvetica-Bold", fontSize=14,
                              textColor=C_WHITE, spaceBefore=16, spaceAfter=2,
                              leftIndent=-0.3*cm, leading=18)
    s["h2"] = ParagraphStyle("h2", fontName="Helvetica-Bold", fontSize=10.5,
                              textColor=C_BLUE, spaceBefore=10, spaceAfter=4,
                              leading=14)
    s["eq"] = ParagraphStyle("eq", fontName="Courier", fontSize=9.5,
                              leftIndent=18, spaceBefore=4, spaceAfter=6,
                              backColor=C_ACCENT, borderPad=7, leading=14)
    s["caption"] = ParagraphStyle("caption", fontName="Helvetica-Oblique",
                                  fontSize=8.5, textColor=colors.HexColor("#555555"),
                                  alignment=TA_CENTER, spaceAfter=4)
    return s


def section_header(title: str, s_h1) -> list:
    """Barra blu con titolo sezione."""
    tbl = Table([[Paragraph(title, s_h1)]], colWidths=[CONTENT_W])
    tbl.setStyle(TableStyle([
        ("BACKGROUND", (0, 0), (-1, -1), C_BLUE),
        ("LEFTPADDING",  (0, 0), (-1, -1), 10),
        ("RIGHTPADDING", (0, 0), (-1, -1), 10),
        ("TOPPADDING",   (0, 0), (-1, -1), 6),
        ("BOTTOMPADDING",(0, 0), (-1, -1), 6),
    ]))
    return [tbl, Spacer(1, 0.25*cm)]


# ─── Genera .tex ──────────────────────────────────────────────────────────────
def generate_tex(induttori: list):
    today = date.today().strftime("%d/%m/%Y")
    lines = [
        r"\documentclass[11pt,a4paper]{article}",
        r"\usepackage[utf8]{inputenc}",
        r"\usepackage[T1]{fontenc}",
        r"\usepackage[margin=2.5cm]{geometry}",
        r"\usepackage{amsmath,amssymb}",
        r"\usepackage{booktabs}",
        r"\usepackage{graphicx}",
        r"\usepackage{float}",
        r"\usepackage[table]{xcolor}",
        r"\usepackage{hyperref}",
        r"\usepackage{fancyhdr}",
        r"\definecolor{darkblue}{HTML}{1a3a5c}",
        r"\pagestyle{fancy}\fancyhf{}",
        r"\rhead{\textcolor{darkblue}{\small Cevolani S.p.A.}}",
        r"\lhead{\textcolor{darkblue}{\small Analisi Termica Forno}}",
        r"\rfoot{\thepage}",
        r"\lfoot{\textcolor{gray}{\tiny Ver. " + VERSIONE + r" -- " + today + r"}}",
        rf"\title{{\textbf{{Report Analisi Termica Forno}}\\[0.5em]\large Caratterizzazione termica degli induttori}}",
        rf"\author{{{AUTORE}}}",
        r"\date{\today}",
        r"\begin{document}",
        r"\maketitle",
        r"\tableofcontents",
        r"\newpage",
        "",
        r"\section{Modello di fitting}",
        r"Ogni intervallo è interpolato con il modello di raffreddamento di Newton:",
        r"\begin{equation}",
        r"  T(t) = T_\infty + A \cdot e^{-(t-t_0)/\tau}",
        r"\end{equation}",
        r"dove $T_\infty = 22{,}99\,^\circ\mathrm{C}$ è la temperatura ambiente media ponderata.",
        r"La regressione non lineare usa il metodo \textit{Trust Region Reflective} (TRF)",
        r"di \texttt{scipy.optimize.curve\_fit}.",
        "",
    ]

    for ind in induttori:
        lines += [
            rf"\section{{{ind['nome']}}}",
            r"\subsection{Intervallo di campionamento}",
            r"\begin{tabular}{ll}\toprule",
            r"\textbf{Parametro} & \textbf{Valore} \\\midrule",
            rf"Inizio & ${ind['t0']}$ s \\",
            rf"Fine & ${ind['t_end']}$ s \\",
            rf"Numero di punti & {ind['n_punti']} \\",
        ]
        if ind["zona_exc"]:
            lines.append(rf"Zona esclusa (peso = 0) & {ind['zona_exc']} \\")
        lines += [r"\bottomrule\end{tabular}", "",
            r"\subsection{Equazione trovata}",
            r"\begin{equation}",
            f"  {ind['equazione_latex']}",
            r"\end{equation}",
            r"\begin{tabular}{lll}\toprule",
            r"\textbf{Param.} & \textbf{Valore} & \textbf{Incertezza ($1\sigma$)} \\\midrule",
            rf"$A$ & ${ind['A']}\,^\circ\mathrm{{C}}$ & $\pm\,{ind['A_err']}\,^\circ\mathrm{{C}}$ \\",
            rf"$\tau$ & ${ind['tau']}\,\mathrm{{s}}$ & $\pm\,{ind['tau_err']}\,\mathrm{{s}}$ \\",
            rf"$R^2$ & \multicolumn{{2}}{{l}}{{{ind['r2']}}} \\",
            r"\bottomrule\end{tabular}", "",
            r"\subsection{Grafico}",
            r"\begin{figure}[H]\centering",
            rf"\includegraphics[width=0.9\textwidth]{{{ind['png']}}}",
            rf"\caption{{Fit esponenziale -- {ind['nome']} [{ind['intervallo']}]}}",
            r"\end{figure}\newpage", "",
        ]

    lines += [
        r"\section{Riepilogo}",
        r"\begin{tabular}{lllll}\toprule",
        r"\textbf{Induttore} & \textbf{Intervallo [s]} & \textbf{A [°C]} & \textbf{$\tau$ [s]} & \textbf{$R^2$} \\\midrule",
    ]
    for ind in induttori:
        lines.append(
            rf"{ind['nome']} & {ind['intervallo']} & {ind['A']} & {ind['tau']} & {ind['r2']} \\"
        )
    lines += [r"\bottomrule\end{tabular}", "", r"\end{document}"]

    (BASE / "report_completo.tex").write_text("\n".join(lines), encoding="utf-8")
    print("report_completo.tex generato.")


# ─── Genera PDF ───────────────────────────────────────────────────────────────
def generate_pdf(induttori: list):
    s = make_styles()
    today_str = date.today().strftime("%d %B %Y")

    frame_cover  = Frame(MARGIN, MARGIN, CONTENT_W, H - 2*MARGIN, id="cover")
    frame_normal = Frame(MARGIN, 2.5*cm, CONTENT_W, H - 2.5*cm - 1.6*cm,
                         id="normal", topPadding=0)

    doc = BaseDocTemplate(str(BASE / "report_completo.pdf"), pagesize=A4)
    doc.addPageTemplates([
        PageTemplate(id="cover",  frames=[frame_cover]),
        PageTemplate(id="normal", frames=[frame_normal]),
    ])

    story = []

    # ── COVER PAGE ──────────────────────────────────────────────────────────────
    # Barra superiore scura
    story.append(Table(
        [[Paragraph("<font color='white' size='11'><b>CEVOLANI S.p.A.</b></font>",
                    ParagraphStyle("ch", alignment=TA_LEFT)),
          Paragraph("<font color='#4a8fc0' size='9'>Analisi Termica — Uso Interno</font>",
                    ParagraphStyle("cr", alignment=TA_LEFT))]],
        colWidths=[CONTENT_W * 0.55, CONTENT_W * 0.45],
        style=TableStyle([
            ("BACKGROUND",    (0, 0), (-1, -1), C_DARK),
            ("TOPPADDING",    (0, 0), (-1, -1), 10),
            ("BOTTOMPADDING", (0, 0), (-1, -1), 10),
            ("LEFTPADDING",   (0, 0), (-1, -1), 14),
        ])
    ))
    story.append(Spacer(1, 4*cm))

    # Titolo principale
    story.append(HRFlowable(width="100%", thickness=4, color=C_BLUE))
    story.append(Spacer(1, 0.4*cm))
    story.append(Paragraph(
        "<font color='#1a3a5c' size='26'><b>Report Analisi Termica Forno</b></font>",
        ParagraphStyle("ct", alignment=TA_CENTER, leading=32)))
    story.append(Spacer(1, 0.3*cm))
    story.append(Paragraph(
        "<font color='#2c5f8a' size='13'>Caratterizzazione termica degli induttori</font>",
        ParagraphStyle("cs", alignment=TA_CENTER, leading=18)))
    story.append(Spacer(1, 0.4*cm))
    story.append(HRFlowable(width="100%", thickness=4, color=C_BLUE))
    story.append(Spacer(1, 2*cm))

    # Scheda documento
    doc_info = [
        ["Documento",           "report_completo"],
        ["Autore",              AUTORE],
        ["Data di emissione",   today_str],
        ["Versione",            VERSIONE],
        ["Stato",               STATO],
        ["Induttori analizzati", str(len(induttori))],
    ]
    story.append(Table(doc_info, colWidths=[5.5*cm, CONTENT_W - 5.5*cm],
                       style=COVER_INFO_STYLE))
    story.append(NextPageTemplate("normal"))
    story.append(PageBreak())

    # ── MODELLO ─────────────────────────────────────────────────────────────────
    story += section_header("1. Modello di fitting", s["h1"])
    story.append(Paragraph(
        "Ogni intervallo di acquisizione è interpolato con la legge di "
        "raffreddamento di Newton, che descrive lo scambio termico convettivo "
        "tra il corpo e l'ambiente:", s["body"]))
    story.append(Paragraph("T(t) = T_inf + A · exp( -(t - t₀) / τ )", s["eq"]))
    story.append(Table([
        ["Simbolo", "Significato",                       "Unità"],
        ["T_inf",   "Temperatura ambiente (fissa)",       "°C"],
        ["A",       "Ampiezza iniziale (libera)",         "°C"],
        ["t₀",      "Istante di riferimento (fisso)",     "s"],
        ["τ",       "Costante di tempo (libera)",         "s"],
    ], colWidths=[3*cm, 9*cm, 3*cm], style=TABLE_STD))
    story.append(Spacer(1, 0.3*cm))
    story.append(Paragraph(
        "La regressione non lineare è eseguita con il metodo "
        "<i>Trust Region Reflective</i> (TRF) tramite "
        "<font name='Courier'>scipy.optimize.curve_fit</font>. "
        f"T_inf = 22.99 °C è la media ponderata sul tempo dell'intera acquisizione "
        "(calcolata con la regola dei trapezi).", s["body"]))
    story.append(Spacer(1, 0.4*cm))

    # ── SEZIONI INDUTTORI ────────────────────────────────────────────────────────
    for i, ind in enumerate(induttori, 1):
        story += section_header(f"{i + 1}. {ind['nome']}", s["h1"])

        # Campionamento
        story.append(Paragraph("Intervallo di campionamento", s["h2"]))
        rows = [["Parametro", "Valore"],
                ["Inizio intervallo",  f"{ind['t0']} s"],
                ["Fine intervallo",    f"{ind['t_end']} s"],
                ["Numero di punti",    ind["n_punti"]]]
        if ind["zona_exc"]:
            rows.append(["Zona esclusa dal fit (σ → ∞)", ind["zona_exc"]])
        story.append(Table(rows, colWidths=[8*cm, CONTENT_W - 8*cm],
                           style=TABLE_STD))
        story.append(Spacer(1, 0.3*cm))

        # Equazione
        story.append(Paragraph("Equazione del modello", s["h2"]))
        story.append(Paragraph(ind["equazione"], s["eq"]))
        story.append(Spacer(1, 0.2*cm))
        story.append(Paragraph("Parametri stimati dalla regressione:", s["body"]))
        story.append(Table([
            ["Parametro", "Valore stimato",      "Incertezza (1σ)",    "Note"],
            ["A",         f"{ind['A']} °C",      f"± {ind['A_err']} °C", "Ampiezza"],
            ["τ",         f"{ind['tau']} s",     f"± {ind['tau_err']} s","Costante di tempo"],
            ["R²",        ind["r2"],             "—",                  "Qualità del fit"],
        ], colWidths=[2.5*cm, 4.5*cm, 4*cm, CONTENT_W - 11*cm],
           style=TABLE_STD))
        story.append(Spacer(1, 0.3*cm))

        # Grafico
        if ind["png"] and Path(ind["png"]).exists():
            story.append(Paragraph("Grafico del fit", s["h2"]))
            story.append(KeepTogether([
                Image(str(ind["png"]), width=CONTENT_W, height=CONTENT_W * 0.6),
                Paragraph(
                    f"Figura {i}: fit esponenziale — {ind['nome']} "
                    f"[{ind['intervallo']}]", s["caption"]),
            ]))
        story.append(Spacer(1, 0.5*cm))

    # ── RIEPILOGO ────────────────────────────────────────────────────────────────
    story.append(PageBreak())
    story += section_header(f"{len(induttori) + 2}. Riepilogo comparativo", s["h1"])
    story.append(Paragraph(
        "Tabella comparativa dei parametri ottimali ottenuti dalla regressione "
        "non lineare per ciascun induttore analizzato.", s["body"]))
    story.append(Spacer(1, 0.2*cm))

    summary = [["Induttore", "Intervallo [s]", "A [°C]", "τ [s]", "R²"]]
    for ind in induttori:
        summary.append([ind["nome"], ind["intervallo"],
                        ind["A"], ind["tau"], ind["r2"]])
    story.append(Table(summary,
                       colWidths=[3.5*cm, 4.5*cm, 3*cm, 3*cm, CONTENT_W - 14*cm],
                       style=TABLE_DARK))
    story.append(Spacer(1, 0.5*cm))
    story.append(Paragraph(
        "<b>Note:</b> tutti i fit usano T_inf = 22.99 °C fissa. "
        "R² calcolato escludendo i punti con peso nullo.", s["body"]))

    doc.build(story, canvasmaker=ProfessionalCanvas)
    print(f"report_completo.pdf generato ({len(induttori)} induttori).")


# ─── Entry point ──────────────────────────────────────────────────────────────
if __name__ == "__main__":
    induttori = collect_induttori()
    if not induttori:
        print("Nessun report*.md trovato nelle cartelle induttore*/.")
    else:
        generate_tex(induttori)
        generate_pdf(induttori)