backend/app/services/export/report_export.py

"""
Report Export Service.

Generates PDF and Word documents from research report data.
Uses ReportLab for PDF and python-docx for Word.
"""

from __future__ import annotations

import io
import logging
from datetime import datetime
from typing import Any, Dict

from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.colors import HexColor
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable
)
from reportlab.lib.units import inch
from reportlab.lib.enums import TA_CENTER, TA_LEFT

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

logger = logging.getLogger(__name__)

ACCENT = HexColor("#005241")
ACCENT_LIGHT = HexColor("#e8f5e9")


def generate_pdf(report: Dict[str, Any]) -> io.BytesIO:
    """Generate a PDF report from report data."""
    buffer = io.BytesIO()
    doc = SimpleDocTemplate(
        buffer, pagesize=A4,
        topMargin=0.75 * inch, bottomMargin=0.75 * inch,
        leftMargin=0.85 * inch, rightMargin=0.85 * inch,
    )

    styles = getSampleStyleSheet()

    # Custom styles
    title_style = ParagraphStyle(
        "ReportTitle", parent=styles["Title"],
        fontSize=22, spaceAfter=6, textColor=ACCENT,
        fontName="Helvetica-Bold",
    )
    subtitle_style = ParagraphStyle(
        "ReportSubtitle", parent=styles["Normal"],
        fontSize=10, textColor=HexColor("#6b7280"), spaceAfter=20,
    )
    heading_style = ParagraphStyle(
        "ReportHeading", parent=styles["Heading2"],
        fontSize=14, textColor=ACCENT, spaceBefore=16, spaceAfter=8,
        fontName="Helvetica-Bold",
    )
    body_style = ParagraphStyle(
        "ReportBody", parent=styles["Normal"],
        fontSize=10, leading=15, spaceAfter=8,
    )

    elements = []

    # Title
    title = report.get("title", "Research Report")
    elements.append(Paragraph(title, title_style))

    # Metadata
    timestamp = report.get("created_at", datetime.utcnow().isoformat())
    insight_type = report.get("insight_type", "general")
    meta = f"Generated: {timestamp[:19]}  ·  Type: {insight_type.replace('_', ' ').title()}"
    elements.append(Paragraph(meta, subtitle_style))

    # Divider
    elements.append(HRFlowable(
        width="100%", thickness=1.5, color=ACCENT, spaceBefore=4, spaceAfter=12,
    ))

    # Summary
    summary = report.get("summary", "")
    if summary:
        elements.append(Paragraph("Executive Summary", heading_style))
        elements.append(Paragraph(summary, body_style))
        elements.append(Spacer(1, 8))

    # Content
    content = report.get("content", "")
    if content:
        elements.append(Paragraph("Detailed Analysis", heading_style))
        for paragraph in content.split("\n\n"):
            paragraph = paragraph.strip()
            if not paragraph:
                continue
            if paragraph.startswith("##"):
                elements.append(Paragraph(paragraph.lstrip("#").strip(), heading_style))
            elif paragraph.startswith("- ") or paragraph.startswith("* "):
                for line in paragraph.split("\n"):
                    bullet_text = line.lstrip("-* ").strip()
                    if bullet_text:
                        elements.append(Paragraph(f"• {bullet_text}", body_style))
            else:
                elements.append(Paragraph(paragraph, body_style))
        elements.append(Spacer(1, 8))

    # Tickers
    tickers = report.get("tickers_json", "")
    if tickers and tickers != "[]":
        import json
        try:
            ticker_list = json.loads(tickers) if isinstance(tickers, str) else tickers
            if ticker_list:
                elements.append(Paragraph("Tickers Analyzed", heading_style))
                elements.append(Paragraph(", ".join(ticker_list), body_style))
                elements.append(Spacer(1, 8))
        except Exception:
            pass

    # Footer
    elements.append(Spacer(1, 20))
    elements.append(HRFlowable(
        width="100%", thickness=0.5, color=HexColor("#d1d5db"), spaceBefore=8, spaceAfter=8,
    ))
    footer_style = ParagraphStyle(
        "Footer", parent=styles["Normal"],
        fontSize=8, textColor=HexColor("#9ca3af"), alignment=TA_CENTER,
    )
    elements.append(Paragraph(
        f"QuantHedge Research Report · Generated {datetime.utcnow().strftime('%Y-%m-%d %H:%M UTC')}",
        footer_style,
    ))

    doc.build(elements)
    buffer.seek(0)
    return buffer


def generate_docx(report: Dict[str, Any]) -> io.BytesIO:
    """Generate a Word document from report data."""
    doc = Document()

    # Set default font
    style = doc.styles["Normal"]
    font = style.font
    font.name = "Calibri"
    font.size = Pt(10)

    # Title
    title = report.get("title", "Research Report")
    heading = doc.add_heading(title, level=0)
    for run in heading.runs:
        run.font.color.rgb = RGBColor(0, 82, 65)

    # Metadata
    timestamp = report.get("created_at", datetime.utcnow().isoformat())
    insight_type = report.get("insight_type", "general")
    meta = doc.add_paragraph()
    meta_run = meta.add_run(f"Generated: {timestamp[:19]}  ·  Type: {insight_type.replace('_', ' ').title()}")
    meta_run.font.size = Pt(9)
    meta_run.font.color.rgb = RGBColor(107, 114, 128)

    doc.add_paragraph("_" * 60)

    # Summary
    summary = report.get("summary", "")
    if summary:
        h = doc.add_heading("Executive Summary", level=1)
        for run in h.runs:
            run.font.color.rgb = RGBColor(0, 82, 65)
        doc.add_paragraph(summary)

    # Content
    content = report.get("content", "")
    if content:
        h = doc.add_heading("Detailed Analysis", level=1)
        for run in h.runs:
            run.font.color.rgb = RGBColor(0, 82, 65)

        for paragraph in content.split("\n\n"):
            paragraph = paragraph.strip()
            if not paragraph:
                continue
            if paragraph.startswith("##"):
                h = doc.add_heading(paragraph.lstrip("#").strip(), level=2)
                for run in h.runs:
                    run.font.color.rgb = RGBColor(0, 82, 65)
            elif paragraph.startswith("- ") or paragraph.startswith("* "):
                for line in paragraph.split("\n"):
                    bullet_text = line.lstrip("-* ").strip()
                    if bullet_text:
                        doc.add_paragraph(bullet_text, style="List Bullet")
            else:
                doc.add_paragraph(paragraph)

    # Tickers
    tickers = report.get("tickers_json", "")
    if tickers and tickers != "[]":
        import json
        try:
            ticker_list = json.loads(tickers) if isinstance(tickers, str) else tickers
            if ticker_list:
                h = doc.add_heading("Tickers Analyzed", level=1)
                for run in h.runs:
                    run.font.color.rgb = RGBColor(0, 82, 65)
                doc.add_paragraph(", ".join(ticker_list))
        except Exception:
            pass

    # Footer
    doc.add_paragraph("_" * 60)
    footer = doc.add_paragraph()
    footer.alignment = WD_ALIGN_PARAGRAPH.CENTER
    run = footer.add_run(f"QuantHedge Research Report · Generated {datetime.utcnow().strftime('%Y-%m-%d %H:%M UTC')}")
    run.font.size = Pt(8)
    run.font.color.rgb = RGBColor(156, 163, 175)

    buffer = io.BytesIO()
    doc.save(buffer)
    buffer.seek(0)
    return buffer