# ============================================================
# 知识文档导入与切块（moduleId: knowledge-ingest, 可重生 ✅）
# plan.md §8.2：PDF/docx/md/txt → chunk → 知识资产（版本化+审批）
# ============================================================
from __future__ import annotations

import os
import re
from typing import Any

# 切块目标长度（字符）与重叠
_CHUNK_SIZE = 500
_CHUNK_OVERLAP = 50


def _ext(path: str) -> str:
    return os.path.splitext(path)[1].lower()


def extract_text_from_bytes(filename: str, raw: bytes) -> list[dict[str, Any]]:
    """按扩展名解析文件为带页/段元数据的文本块列表（尚未切 chunk）。

    Returns: [{text, page?, heading?}, ...]
    """
    name = filename or "upload.txt"
    ext = _ext(name)
    if ext in (".md", ".txt", ".markdown"):
        text = raw.decode("utf-8", errors="replace")
        return _split_markdown_sections(text)
    if ext == ".pdf":
        return _extract_pdf(raw)
    if ext in (".docx",):
        return _extract_docx(raw)
    if ext in (".xlsx", ".xlsm"):
        return _extract_xlsx(raw)
    # 兜底当纯文本
    try:
        return [{"text": raw.decode("utf-8"), "page": 1}]
    except UnicodeDecodeError as exc:
        raise ValueError(f"不支持的文件类型或编码：{name}") from exc


def extract_text_from_path(path: str) -> list[dict[str, Any]]:
    """从本地路径读取并解析。"""
    if not os.path.isfile(path):
        raise FileNotFoundError(f"文件不存在：{path}")
    with open(path, "rb") as f:
        raw = f.read()
    return extract_text_from_bytes(os.path.basename(path), raw)


def _split_markdown_sections(text: str) -> list[dict[str, Any]]:
    parts: list[dict[str, Any]] = []
    current_heading = ""
    buf: list[str] = []
    for line in text.splitlines():
        if re.match(r"^#{1,3}\s+", line):
            if buf:
                parts.append({"text": "\n".join(buf).strip(), "heading": current_heading or None})
                buf = []
            current_heading = re.sub(r"^#{1,3}\s+", "", line).strip()
            buf.append(line)
        else:
            buf.append(line)
    if buf:
        parts.append({"text": "\n".join(buf).strip(), "heading": current_heading or None})
    return [p for p in parts if p["text"]]


def _extract_pdf(raw: bytes) -> list[dict[str, Any]]:
    try:
        import pdfplumber
    except ImportError as exc:
        raise ValueError("解析 PDF 需要安装 pdfplumber：pip install pdfplumber") from exc
    from io import BytesIO
    pages: list[dict[str, Any]] = []
    with pdfplumber.open(BytesIO(raw)) as pdf:
        for i, page in enumerate(pdf.pages, start=1):
            t = (page.extract_text() or "").strip()
            if t:
                pages.append({"text": t, "page": i})
    if not pages:
        raise ValueError("PDF 未提取到文本（可能是扫描件）")
    return pages


def _extract_docx(raw: bytes) -> list[dict[str, Any]]:
    try:
        from docx import Document
    except ImportError as exc:
        raise ValueError("解析 docx 需要安装 python-docx：pip install python-docx") from exc
    from io import BytesIO
    doc = Document(BytesIO(raw))
    paras = [p.text.strip() for p in doc.paragraphs if p.text and p.text.strip()]
    if not paras:
        raise ValueError("docx 未提取到文本")
    return [{"text": "\n".join(paras), "page": 1}]


def _extract_xlsx(raw: bytes) -> list[dict[str, Any]]:
    from io import BytesIO
    from openpyxl import load_workbook
    wb = load_workbook(BytesIO(raw), data_only=True, read_only=True)
    parts: list[dict[str, Any]] = []
    for sheet in wb.worksheets:
        rows = []
        for row in sheet.iter_rows(values_only=True):
            cells = [str(c) for c in row if c is not None and str(c).strip()]
            if cells:
                rows.append(" | ".join(cells))
        if rows:
            parts.append({"text": f"# {sheet.title}\n" + "\n".join(rows), "heading": sheet.title})
    if not parts:
        raise ValueError("xlsx 无有效单元格")
    return parts


def chunk_sections(sections: list[dict[str, Any]], *,
                   size: int = _CHUNK_SIZE, overlap: int = _CHUNK_OVERLAP) -> list[dict[str, Any]]:
    """把段落/页切成固定长度 chunk（带重叠）。"""
    chunks: list[dict[str, Any]] = []
    idx = 0
    for sec in sections:
        text = (sec.get("text") or "").strip()
        if not text:
            continue
        heading = sec.get("heading")
        page = sec.get("page")
        if len(text) <= size:
            chunks.append({
                "chunkId": f"c{idx:04d}", "text": text,
                "heading": heading, "page": page, "seq": idx,
            })
            idx += 1
            continue
        start = 0
        while start < len(text):
            end = min(start + size, len(text))
            piece = text[start:end].strip()
            if piece:
                chunks.append({
                    "chunkId": f"c{idx:04d}", "text": piece,
                    "heading": heading, "page": page, "seq": idx,
                })
                idx += 1
            if end >= len(text):
                break
            start = max(end - overlap, start + 1)
    return chunks


def preview_ingest(filename: str, raw: bytes | None = None, path: str | None = None,
                   *, kind: str = "sop", title: str | None = None) -> dict[str, Any]:
    """预览导入：解析+切块，不写库。"""
    if path:
        sections = extract_text_from_path(path)
        fname = os.path.basename(path)
    elif raw is not None:
        sections = extract_text_from_bytes(filename, raw)
        fname = filename
    else:
        raise ValueError("需要提供 path 或 raw")
    chunks = chunk_sections(sections)
    title = title or os.path.splitext(fname)[0]
    return {
        "filename": fname,
        "title": title,
        "kind": kind,
        "sectionCount": len(sections),
        "chunkCount": len(chunks),
        "preview": [{"seq": c["seq"], "heading": c.get("heading"), "page": c.get("page"),
                     "chars": len(c["text"]), "snippet": c["text"][:80]} for c in chunks[:8]],
        "chunks": chunks,
    }


def confirmation_for_knowledge_import(preview: dict[str, Any]) -> tuple[str, list[str]]:
    """P2 确认卡文案。"""
    title = f"导入知识文档《{preview.get('title')}》"
    lines = [
        f"文件：{preview.get('filename')}",
        f"类型：{preview.get('kind')}",
        f"切块：{preview.get('chunkCount')} 段（来自 {preview.get('sectionCount')} 节/页）",
        "入库后可检索；默认已审批（approved=true）。",
    ]
    return title, lines


def apply_knowledge_import(preview: dict[str, Any], *, tags: list[str] | None = None,
                           store: Any = None) -> dict[str, Any]:
    """把预览结果写入知识库（带 chunks）。"""
    from server.knowledge.assets import get_knowledge
    kb = store or get_knowledge()
    chunks = preview.get("chunks") or []
    content = "\n\n".join(
        (f"【{c.get('heading') or '段落'}】\n" if c.get("heading") else "") + c["text"]
        for c in chunks
    )
    if not content.strip():
        raise ValueError("无正文可入库")
    asset = kb.add_with_chunks(
        kind=str(preview.get("kind") or "sop"),
        title=str(preview.get("title") or preview.get("filename") or "导入文档"),
        content=content[:8000],  # 资产摘要正文（检索仍优先 chunk）
        chunks=chunks,
        tags=tags or ["导入", str(preview.get("filename") or "")],
        source=str(preview.get("filename") or ""),
        approved=True,
    )
    return {"assetId": asset["assetId"], "title": asset["title"],
            "version": asset["version"], "chunkCount": len(asset.get("chunks") or [])}


def bind_world_to_identity(world: dict[str, Any], *, sources: list[str] | None = None) -> dict[str, Any]:
    """把当前登录用户/租户写到世界元数据（分析/导入后绑定归属）。"""
    from datetime import datetime
    from server.auth.context import get_identity
    from server.timeutil import fmt_dt

    identity = get_identity()
    meta = dict(world.get("meta") or {})
    meta.update({
        "ownerUserId": identity.user_id,
        "ownerUsername": identity.username,
        "ownerFullname": identity.fullname,
        "tenantUuid": identity.tenant_uuid,
        "boundAt": fmt_dt(datetime.now()),
        "sources": list(sources or meta.get("sources") or []),
    })
    world["meta"] = meta
    return meta


def _knowledge_cell(value: Any) -> str:
    if value is None:
        return ""
    if isinstance(value, (list, tuple, set)):
        value = "、".join(str(item) for item in value if item not in (None, ""))
    return str(value).replace("\r", " ").replace("\n", " ").strip()


def _append_rows_section(
    sections: list[dict[str, Any]],
    *,
    heading: str,
    rows: list[dict[str, Any]],
    columns: list[tuple[str, str]],
) -> None:
    if not rows:
        return
    lines = [f"# {heading}", f"记录数：{len(rows)}"]
    for row in rows:
        fields = [
            f"{label}={_knowledge_cell(row.get(key))}"
            for key, label in columns
            if _knowledge_cell(row.get(key))
        ]
        if fields:
            lines.append("- " + "；".join(fields))
    sections.append({"heading": heading, "text": "\n".join(lines)})


def _project_source_sections(paths: list[str]) -> list[dict[str, Any]]:
    """保留源文件全部可读字段；标准化失败的列也能进入知识库检索。"""
    sections: list[dict[str, Any]] = []
    seen: set[str] = set()
    for raw_path in paths[:32]:
        path = os.path.abspath(str(raw_path or ""))
        if not path or path in seen or not os.path.isfile(path):
            continue
        seen.add(path)
        if os.path.getsize(path) > 25 * 1024 * 1024:
            continue
        name = os.path.basename(path)
        try:
            extracted = extract_text_from_path(path)
        except Exception:
            if _ext(path) not in (".csv", ".txt"):
                continue
            try:
                with open(path, "rb") as source:
                    raw = source.read()
            except OSError:
                continue
            text = ""
            for encoding in ("utf-8-sig", "gb18030"):
                try:
                    text = raw.decode(encoding)
                    break
                except UnicodeDecodeError:
                    continue
            extracted = [{"text": text, "heading": name}] if text.strip() else []
        for section in extracted:
            body = str(section.get("text") or "").strip()
            if not body:
                continue
            heading = str(section.get("heading") or "原始内容")
            sections.append({
                "heading": f"源文件·{name}·{heading}",
                "page": section.get("page"),
                "text": f"# 源文件 {name}\n## {heading}\n{body}",
            })
    return sections


def ingest_project_analyze_report(
    deep: dict[str, Any],
    *,
    world: dict[str, Any] | None = None,
) -> dict[str, Any]:
    """项目分析结果 → 当前租户知识库（可检索）+ 绑定登录用户。

    - 知识库按 tenant_uuid 隔离（get_knowledge）
    - 资产标签含用户/项目/来源，便于问答引用
    """
    from server.auth.context import get_identity
    from server.knowledge.embedding import index_units
    from server.knowledge.assets import get_knowledge

    identity = get_identity()
    if world is not None:
        bind_world_to_identity(world, sources=list(deep.get("sources") or []))

    proj = str(deep.get("projectName") or "当前项目")
    summary = deep.get("summary") or {}
    sections: list[dict[str, Any]] = []

    md = (deep.get("markdown") or "").strip()
    if md:
        sections.append({"text": md, "heading": f"项目分析·{proj}"})

    # 原始表格作为数据知识保存，未知列不会因主数据映射失败而丢失。
    sections.extend(_project_source_sections(list(deep.get("sourcePaths") or [])))

    # 卡片只展示抽样，知识库保存项目世界中的完整标准化数据集。
    source = world or {}
    datasets: list[tuple[str, list[dict[str, Any]], list[tuple[str, str]]]] = [
        (f"{proj} 物料主数据", list(source.get("flexMaterials") or deep.get("materials") or []), [
            ("code", "物料编码"), ("name", "物料名称"), ("type", "类型"),
            ("unit", "单位"), ("stock", "库存"), ("sourcingType", "来源"),
        ]),
        (f"{proj} BOM", list(source.get("flexBom") or []), [
            ("productCode", "父项"), ("materialCode", "子项"),
            ("quantity", "用量"), ("isKey", "关键件"),
        ]),
        (f"{proj} 工艺路线", list(source.get("flexRoutings") or deep.get("routings") or []), [
            ("productCode", "产品"), ("seq", "顺序"), ("operationCode", "工序编码"),
            ("operationName", "工序名称"), ("stdTimePerUnit", "标准工时"),
            ("sourcingType", "来源"),
        ]),
        (f"{proj} 设备台账", list(source.get("flexEquipment") or deep.get("equipment") or []), [
            ("code", "设备编码"), ("name", "设备名称"), ("status", "状态"),
            ("financeCode", "财务编号"), ("internalCode", "厂内编号"),
            ("assetCode", "固定资产编号"), ("factoryCode", "出厂编号"),
            ("capabilities", "能力"), ("zone", "区域"), ("availabilityRate", "可用率"),
        ]),
        (f"{proj} 项目订单", list(source.get("flexOrders") or deep.get("orders") or []), [
            ("orderNo", "订单号"), ("productCode", "产品"), ("productName", "产品名称"),
            ("quantity", "数量"), ("dueDate", "交期"), ("status", "状态"),
            ("customerName", "客户"),
        ]),
        (f"{proj} 工序字典", list(source.get("flexOperations") or []), [
            ("code", "工序编码"), ("name", "工序名称"), ("type", "类型"),
            ("sourcingType", "来源"), ("changeoverMin", "换型时间"),
        ]),
        (f"{proj} 生产区域", list(source.get("flexZones") or []), [
            ("code", "区域编码"), ("name", "区域名称"),
        ]),
    ]
    for heading, rows, columns in datasets:
        _append_rows_section(sections, heading=heading, rows=rows, columns=columns)
    plan = deep.get("plan") or []
    if plan:
        sections.append({
            "heading": "补数计划",
            "text": f"# {proj} 补数 Plan\n" + "\n".join(f"- {p}" for p in plan[:20]),
        })

    if not sections:
        return {"skipped": True, "reason": "无分析正文可入库"}

    chunks = chunk_sections(sections)
    title = f"项目分析·{proj}"
    tags = [
        "项目分析", "自动入库", "完整数据集",
        f"user:{identity.username}",
        f"uid:{identity.user_id}",
        f"tenant:{identity.tenant_uuid}",
        proj,
    ]
    for src in (deep.get("sources") or [])[:6]:
        tags.append(str(src)[:48])

    preview = {
        "filename": f"project-analyze-{identity.user_id}.md",
        "title": title,
        "kind": "case",
        "sectionCount": len(sections),
        "chunkCount": len(chunks),
        "chunks": chunks,
    }
    applied = apply_knowledge_import(preview, tags=tags)
    try:
        index_units(get_knowledge().iter_search_units())
        applied["indexed"] = True
    except Exception:
        applied["indexed"] = False
    applied["ownerUserId"] = identity.user_id
    applied["tenantUuid"] = identity.tenant_uuid
    applied["summary"] = summary
    return applied