"""Report generation: Excel / Word / PDF."""
import uuid
from pathlib import Path
from uuid import UUID

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.config import settings
from app.models.assessment import FraudAssessment, ReviewStatus
from app.models.transaction import TransactionRecord
from app.models.report import ExportReport, ReportType
from app.schemas.report import ReportCreate


async def generate_report(case_id: UUID, body: ReportCreate, db: AsyncSession) -> ExportReport:
    result = await db.execute(
        select(ExportReport)
        .where(ExportReport.case_id == case_id, ExportReport.report_type == body.report_type)
    )
    existing = list(result.scalars().all())
    version = len(existing) + 1

    report_dir = settings.upload_path / str(case_id) / "reports"
    report_dir.mkdir(parents=True, exist_ok=True)

    if body.report_type == ReportType.excel:
        file_path = await _gen_excel(case_id, report_dir, body, db)
    elif body.report_type == ReportType.word:
        file_path = await _gen_word(case_id, report_dir, body, db)
    else:
        file_path = await _gen_pdf(case_id, report_dir, body, db)

    relative = str(file_path.relative_to(settings.upload_path))

    snap_result = await db.execute(
        select(FraudAssessment).where(
            FraudAssessment.case_id == case_id,
            FraudAssessment.review_status == ReviewStatus.confirmed,
        )
    )
    snapshot = [
        {"amount": float(a.assessed_amount), "reason": a.reason}
        for a in snap_result.scalars().all()
    ]

    report = ExportReport(
        case_id=case_id,
        report_type=body.report_type,
        file_path=relative,
        version=version,
        content_snapshot={"assessments": snapshot},
    )
    db.add(report)
    await db.flush()
    await db.refresh(report)
    return report


# ── helpers ──

async def _get_confirmed(case_id: UUID, db: AsyncSession) -> list[FraudAssessment]:
    r = await db.execute(
        select(FraudAssessment).where(
            FraudAssessment.case_id == case_id,
            FraudAssessment.review_status == ReviewStatus.confirmed,
        )
    )
    return list(r.scalars().all())


async def _get_all_assessments(case_id: UUID, db: AsyncSession) -> dict:
    r = await db.execute(select(FraudAssessment).where(FraudAssessment.case_id == case_id))
    return {a.transaction_id: a for a in r.scalars().all()}


async def _get_all_transactions(case_id: UUID, db: AsyncSession) -> list[TransactionRecord]:
    r = await db.execute(
        select(TransactionRecord).where(TransactionRecord.case_id == case_id)
    )
    return list(r.scalars().all())


async def _get_inquiry_suggestions(case_id: UUID, db: AsyncSession) -> list[str]:
    from app.services.assessment_service import generate_inquiry_suggestions
    return await generate_inquiry_suggestions(case_id, db)


# ── Excel ──

async def _gen_excel(case_id: UUID, report_dir: Path, body: ReportCreate, db: AsyncSession) -> Path:
    from openpyxl import Workbook

    wb = Workbook()
    sheet_created = False

    if body.include_summary:
        ws = wb.active if not sheet_created else wb.create_sheet()
        ws.title = "被骗金额汇总"
        ws.append(["交易时间", "金额(元)", "方向", "对方", "来源APP", "备注", "置信度", "认定理由"])
        for a in await _get_confirmed(case_id, db):
            tx = await db.get(TransactionRecord, a.transaction_id)
            if tx:
                ws.append([
                    tx.trade_time.strftime("%Y-%m-%d %H:%M:%S"),
                    float(a.assessed_amount),
                    "支出" if tx.direction.value == "out" else "收入",
                    tx.counterparty_name,
                    tx.source_app.value,
                    tx.remark,
                    tx.confidence,
                    a.reason[:100],
                ])
        sheet_created = True

    if body.include_transactions:
        ws2 = wb.active if not sheet_created else wb.create_sheet()
        if not sheet_created:
            ws2.title = "交易明细"
        else:
            ws2.title = "交易明细"
        ws2.append([
            "交易ID", "证据图片ID", "交易时间", "金额(元)", "方向", "来源APP",
            "对方名称", "对方账号", "本方账户尾号", "订单号", "备注", "识别置信度",
            "是否重复", "是否中转", "聚类ID", "记录创建时间",
            "认定置信等级", "认定金额(元)", "认定理由", "排除条件",
            "复核状态", "复核备注", "复核人", "复核时间",
        ])
        assessment_by_tx = await _get_all_assessments(case_id, db)
        for tx in await _get_all_transactions(case_id, db):
            fa = assessment_by_tx.get(tx.id)
            ws2.append([
                str(tx.id),
                str(tx.evidence_image_id) if tx.evidence_image_id else "",
                tx.trade_time.strftime("%Y-%m-%d %H:%M:%S"),
                float(tx.amount),
                tx.direction.value,
                tx.source_app.value,
                tx.counterparty_name,
                tx.counterparty_account,
                tx.self_account_tail_no,
                tx.order_no,
                tx.remark,
                float(tx.confidence),
                "是" if tx.is_duplicate else "否",
                "是" if tx.is_transit else "否",
                str(tx.cluster_id) if tx.cluster_id else "",
                tx.created_at.strftime("%Y-%m-%d %H:%M:%S") if tx.created_at else "",
                fa.confidence_level.value if fa else "",
                float(fa.assessed_amount) if fa else "",
                fa.reason if fa else "",
                fa.exclude_reason if fa else "",
                fa.review_status.value if fa else "",
                fa.review_note if fa else "",
                fa.reviewed_by if fa else "",
                fa.reviewed_at.strftime("%Y-%m-%d %H:%M:%S") if (fa and fa.reviewed_at) else "",
            ])
        sheet_created = True

    if body.include_reasons:
        ws3 = wb.active if not sheet_created else wb.create_sheet()
        ws3.title = "认定理由与排除说明"
        ws3.append(["交易时间", "金额(元)", "置信等级", "认定理由", "排除条件", "复核状态"])
        assessment_by_tx = await _get_all_assessments(case_id, db)
        for tx in await _get_all_transactions(case_id, db):
            fa = assessment_by_tx.get(tx.id)
            if not fa:
                continue
            ws3.append([
                tx.trade_time.strftime("%Y-%m-%d %H:%M:%S"),
                float(tx.amount),
                fa.confidence_level.value,
                fa.reason,
                fa.exclude_reason,
                fa.review_status.value,
            ])
        sheet_created = True

    if body.include_inquiry:
        ws4 = wb.active if not sheet_created else wb.create_sheet()
        ws4.title = "笔录辅助问询建议"
        ws4.append(["序号", "问询建议"])
        suggestions = await _get_inquiry_suggestions(case_id, db)
        for i, s in enumerate(suggestions, 1):
            ws4.append([i, s])
        sheet_created = True

    if not sheet_created:
        ws = wb.active
        ws.title = "报告"
        ws.append(["未选择任何报告内容"])

    file_path = report_dir / f"report_{uuid.uuid4().hex[:8]}.xlsx"
    wb.save(file_path)
    return file_path


# ── Word ──

async def _gen_word(case_id: UUID, report_dir: Path, body: ReportCreate, db: AsyncSession) -> Path:
    from docx import Document

    doc = Document()
    doc.add_heading("受害人被骗金额汇总报告", level=1)

    if body.include_summary:
        confirmed = await _get_confirmed(case_id, db)
        total = sum(float(a.assessed_amount) for a in confirmed)
        doc.add_paragraph(f"已确认被骗金额: ¥{total:,.2f}")
        doc.add_paragraph(f"已确认交易笔数: {len(confirmed)}")
        table = doc.add_table(rows=1, cols=4)
        table.style = "Table Grid"
        hdr = table.rows[0].cells
        hdr[0].text, hdr[1].text, hdr[2].text, hdr[3].text = "交易时间", "金额(元)", "对方", "认定理由"
        for a in confirmed:
            tx = await db.get(TransactionRecord, a.transaction_id)
            row = table.add_row().cells
            row[0].text = tx.trade_time.strftime("%Y-%m-%d %H:%M") if tx else ""
            row[1].text = f"{float(a.assessed_amount):,.2f}"
            row[2].text = tx.counterparty_name if tx else ""
            row[3].text = a.reason[:80]

    if body.include_transactions:
        doc.add_heading("交易明细", level=2)
        table2 = doc.add_table(rows=1, cols=6)
        table2.style = "Table Grid"
        for i, h in enumerate(["交易时间", "金额", "方向", "对方", "订单号", "备注"]):
            table2.rows[0].cells[i].text = h
        for tx in await _get_all_transactions(case_id, db):
            row = table2.add_row().cells
            row[0].text = tx.trade_time.strftime("%Y-%m-%d %H:%M")
            row[1].text = f"{float(tx.amount):,.2f}"
            row[2].text = tx.direction.value
            row[3].text = tx.counterparty_name[:20]
            row[4].text = tx.order_no[:20]
            row[5].text = tx.remark[:30]

    if body.include_reasons:
        doc.add_heading("认定理由与排除说明", level=2)
        assessment_by_tx = await _get_all_assessments(case_id, db)
        for tx in await _get_all_transactions(case_id, db):
            fa = assessment_by_tx.get(tx.id)
            if not fa:
                continue
            doc.add_paragraph(
                f"[{tx.trade_time.strftime('%Y-%m-%d %H:%M')}] ¥{float(tx.amount):,.2f} "
                f"— {fa.confidence_level.value} — {fa.reason[:100]}"
            )
            if fa.exclude_reason:
                doc.add_paragraph(f"  排除条件: {fa.exclude_reason[:100]}")

    if body.include_inquiry:
        doc.add_heading("笔录辅助问询建议", level=2)
        suggestions = await _get_inquiry_suggestions(case_id, db)
        for i, s in enumerate(suggestions, 1):
            doc.add_paragraph(f"{i}. {s}")

    file_path = report_dir / f"report_{uuid.uuid4().hex[:8]}.docx"
    doc.save(file_path)
    return file_path


# ── PDF ──

async def _gen_pdf(case_id: UUID, report_dir: Path, body: ReportCreate, db: AsyncSession) -> Path:
    from reportlab.lib.pagesizes import A4
    from reportlab.lib import colors
    from reportlab.lib.units import mm
    from reportlab.platypus import SimpleDocTemplate, Table as RLTable, TableStyle, Paragraph, Spacer
    from reportlab.lib.styles import getSampleStyleSheet
    from reportlab.pdfbase import pdfmetrics
    from reportlab.pdfbase.ttfonts import TTFont
    import os

    font_registered = False
    for font_path in [
        "/System/Library/Fonts/PingFang.ttc",
        "/System/Library/Fonts/STHeiti Medium.ttc",
        "/usr/share/fonts/truetype/noto/NotoSansCJK-Regular.ttc",
        "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
    ]:
        if os.path.exists(font_path):
            try:
                pdfmetrics.registerFont(TTFont("ChineseFont", font_path, subfontIndex=0))
                font_registered = True
                break
            except Exception:
                continue

    font_name = "ChineseFont" if font_registered else "Helvetica"
    styles = getSampleStyleSheet()
    title_style = styles["Title"]
    title_style.fontName = font_name
    normal_style = styles["Normal"]
    normal_style.fontName = font_name
    h2_style = styles["Heading2"]
    h2_style.fontName = font_name

    file_path = report_dir / f"report_{uuid.uuid4().hex[:8]}.pdf"
    doc = SimpleDocTemplate(str(file_path), pagesize=A4,
                            leftMargin=15 * mm, rightMargin=15 * mm,
                            topMargin=20 * mm, bottomMargin=20 * mm)
    elements = []
    elements.append(Paragraph("受害人被骗金额汇总报告", title_style))
    elements.append(Spacer(1, 10 * mm))

    def _make_table(header, rows, col_widths):
        data = [header] + rows
        tbl = RLTable(data, colWidths=col_widths, repeatRows=1)
        tbl.setStyle(TableStyle([
            ("FONTNAME", (0, 0), (-1, -1), font_name),
            ("FONTSIZE", (0, 0), (-1, -1), 8),
            ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#1677ff")),
            ("TEXTCOLOR", (0, 0), (-1, 0), colors.white),
            ("GRID", (0, 0), (-1, -1), 0.5, colors.grey),
            ("VALIGN", (0, 0), (-1, -1), "TOP"),
            ("TOPPADDING", (0, 0), (-1, -1), 3),
            ("BOTTOMPADDING", (0, 0), (-1, -1), 3),
        ]))
        return tbl

    if body.include_summary:
        confirmed = await _get_confirmed(case_id, db)
        total = sum(float(a.assessed_amount) for a in confirmed)
        elements.append(Paragraph(f"已确认被骗金额: ¥{total:,.2f}", normal_style))
        elements.append(Paragraph(f"已确认交易笔数: {len(confirmed)}", normal_style))
        elements.append(Spacer(1, 6 * mm))
        header = ["交易时间", "金额(元)", "对方", "认定理由"]
        rows = []
        for a in confirmed:
            tx = await db.get(TransactionRecord, a.transaction_id)
            rows.append([
                tx.trade_time.strftime("%Y-%m-%d %H:%M") if tx else "",
                f"{float(a.assessed_amount):,.2f}",
                (tx.counterparty_name if tx else "")[:20],
                Paragraph(a.reason[:120], normal_style),
            ])
        if rows:
            elements.append(_make_table(header, rows, [38*mm, 25*mm, 35*mm, 72*mm]))
        else:
            elements.append(Paragraph("暂无已确认交易记录。", normal_style))
        elements.append(Spacer(1, 8 * mm))

    if body.include_transactions:
        elements.append(Paragraph("交易明细", h2_style))
        elements.append(Spacer(1, 4 * mm))
        header = ["交易时间", "金额", "方向", "对方", "订单号"]
        rows = []
        for tx in await _get_all_transactions(case_id, db):
            rows.append([
                tx.trade_time.strftime("%Y-%m-%d %H:%M"),
                f"{float(tx.amount):,.2f}",
                "出" if tx.direction.value == "out" else "入",
                tx.counterparty_name[:16],
                tx.order_no[:16],
            ])
        if rows:
            elements.append(_make_table(header, rows, [38*mm, 22*mm, 12*mm, 48*mm, 48*mm]))
        elements.append(Spacer(1, 8 * mm))

    if body.include_reasons:
        elements.append(Paragraph("认定理由与排除说明", h2_style))
        elements.append(Spacer(1, 4 * mm))
        assessment_by_tx = await _get_all_assessments(case_id, db)
        for tx in await _get_all_transactions(case_id, db):
            fa = assessment_by_tx.get(tx.id)
            if not fa:
                continue
            line = (
                f"[{tx.trade_time.strftime('%m-%d %H:%M')}] ¥{float(tx.amount):,.2f} "
                f"| {fa.confidence_level.value} | {fa.reason[:80]}"
            )
            elements.append(Paragraph(line, normal_style))
            if fa.exclude_reason:
                elements.append(Paragraph(f"  排除: {fa.exclude_reason[:80]}", normal_style))
        elements.append(Spacer(1, 8 * mm))

    if body.include_inquiry:
        elements.append(Paragraph("笔录辅助问询建议", h2_style))
        elements.append(Spacer(1, 4 * mm))
        suggestions = await _get_inquiry_suggestions(case_id, db)
        for i, s in enumerate(suggestions, 1):
            elements.append(Paragraph(f"{i}. {s}", normal_style))
        elements.append(Spacer(1, 8 * mm))

    if not elements or len(elements) <= 2:
        elements.append(Paragraph("未选择任何报告内容。", normal_style))

    doc.build(elements)
    return file_path