"""DOCX report generator for compliance analysis results.

Uses python-docx (already in requirements.txt). Returns raw bytes so the
caller can stream the response without writing to disk.
"""
from __future__ import annotations

from datetime import datetime, timezone
from io import BytesIO

from docx import Document
from docx.shared import Pt, RGBColor
from docx.enum.text import WD_ALIGN_PARAGRAPH

from app.domain.compliance.ports import AnalysisRecord

_STATUS_LABEL = {"ok": "Compliant", "warn": "Warning", "risk": "Non-Compliant"}
_STATUS_COLOR = {
    "ok": RGBColor(0x22, 0x8B, 0x22),
    "warn": RGBColor(0xFF, 0x8C, 0x00),
    "risk": RGBColor(0xDC, 0x14, 0x3C),
}


def generate_docx(record: AnalysisRecord) -> bytes:
    """Generate a compliance report DOCX and return its raw bytes.

    Structure:
    - Cover: document name, standard, date, risk score
    - Executive summary (conclusion)
    - Findings table
    - Recommended actions
    - Footer note
    """
    doc = Document()

    # ── Cover ──────────────────────────────────────────────────────────────────
    title_para = doc.add_heading("Compliance Analysis Report", level=0)
    title_para.alignment = WD_ALIGN_PARAGRAPH.CENTER

    doc.add_paragraph("")
    meta_table = doc.add_table(rows=4, cols=2)
    meta_table.style = "Table Grid"
    labels = ["Document", "Standard", "Date", "Risk Score"]
    values = [
        record.doc_name,
        record.standard_name,
        record.created_at.strftime("%Y-%m-%d %H:%M UTC") if record.created_at else "",
        f"{record.risk_score} / 100",
    ]
    for i, (label, value) in enumerate(zip(labels, values)):
        meta_table.cell(i, 0).text = label
        meta_table.cell(i, 1).text = value

    # ── Executive Summary ──────────────────────────────────────────────────────
    doc.add_heading("Executive Summary", level=1)
    doc.add_paragraph(record.conclusion)

    # ── Findings ───────────────────────────────────────────────────────────────
    doc.add_heading("Findings", level=1)
    if record.findings:
        table = doc.add_table(rows=1, cols=4)
        table.style = "Table Grid"
        hdr = table.rows[0].cells
        for i, h in enumerate(["#", "Status", "Title", "Description / Clause"]):
            hdr[i].text = h
            for run in hdr[i].paragraphs[0].runs:
                run.bold = True

        for f in record.findings:
            row = table.add_row().cells
            row[0].text = str(f.seq + 1)
            row[1].text = _STATUS_LABEL.get(f.status, f.status)
            row[2].text = f.title
            desc = f.description
            if f.clause_ref:
                desc += f"\n[{f.clause_ref}]"
            row[3].text = desc
    else:
        doc.add_paragraph("No findings recorded.")

    # ── Recommended Actions ────────────────────────────────────────────────────
    doc.add_heading("Recommended Actions", level=1)
    for i, action in enumerate(record.actions, start=1):
        label = action.get("label", "Action")
        value = action.get("value", "")
        doc.add_paragraph(f"{i}. {label}: {value}", style="List Number")

    # ── Footer note ────────────────────────────────────────────────────────────
    doc.add_paragraph("")
    footer = doc.add_paragraph(
        f"Generated by AI Regulation Analysis System — {datetime.now(timezone.utc).strftime('%Y-%m-%d')}"
    )
    footer.alignment = WD_ALIGN_PARAGRAPH.CENTER
    for run in footer.runs:
        run.font.size = Pt(8)
        run.font.color.rgb = RGBColor(0x88, 0x88, 0x88)

    buf = BytesIO()
    doc.save(buf)
    return buf.getvalue()