"""Excel 双向导入/导出 (openpyxl)

- 物料导入 / 导出
- BOM 导入(含组成行)
- 交易(入库/出库)批量导入
- 模板下载
"""
import os
import re
import csv
from datetime import date
from openpyxl import Workbook, load_workbook
from openpyxl.styles import Font, PatternFill, Alignment

from models import db, Material, Inbound, Bom, BomItem, OperationLog


# ---------------- 交易(入库/出库)批量导入 ----------------
def _cell(r, i):
    """安全取单元格, 越界返回 None"""
    try:
        return r[i] if i is not None else None
    except (IndexError, TypeError):
        return None


def read_transactions(path):
    """Excel / CSV -> [{part_number, qty, batch_no, date, remark}]

    表头识别: 物料编号 / 数量 / 批次 / 日期 / 备注 (名称大小写/中英均可)。
    """
    if str(path).lower().endswith(".csv"):
        with open(path, newline="", encoding="utf-8-sig") as f:
            rows = [r for r in csv.reader(f)]
    else:
        wb = load_workbook(path, data_only=True)
        ws = wb.active
        rows = [list(r) for r in ws.iter_rows(values_only=True)]
    if not rows:
        return []
    header = [str(c).strip() if c is not None else "" for c in rows[0]]
    idx = {h: i for i, h in enumerate(header)}

    def col(*names):
        for n in names:
            if n in idx:
                return idx[n]
        return None

    c_pn = col("物料编号", "Part Number", "part_number", "编号")
    c_qty = col("数量", "qty", "qty_per_unit", "用量")
    c_batch = col("批次", "batch_no", "batch")
    c_date = col("日期", "date", "occur_date", "业务日期")
    c_remark = col("备注", "remark", "note")
    out = []
    for r in rows[1:]:
        if not any(c not in (None, "") for c in r):
            continue
        pn = str(_cell(r, c_pn) or "").strip()
        if not pn:
            continue
        q = _f(_cell(r, c_qty))
        batch = str(_cell(r, c_batch) or "").strip()
        d = str(_cell(r, c_date) or "").strip()
        remark = str(_cell(r, c_remark) or "").strip()
        out.append({"part_number": pn, "qty": q, "batch_no": batch,
                    "date": d, "remark": remark})
    return out


def build_transaction_template(path, kind="inbound"):
    wb = Workbook()
    ws = wb.active
    ws.append(["物料编号", "数量", "批次", "日期", "备注"])
    for c in ws[1]:
        c.font = Font(bold=True)
    ws.append(["P0001", "100", "B20260911", "2026-09-11", "示例到货"])
    ws.append(["P0002", "50", "B20260911", "2026-09-11", "示例到货"])
    wb.save(path)
    return path


# ---------------- 物料 ----------------
def read_materials(path):
    """返回 [{part_number, manufacturer, unit, safety_stock, opening_stock}]"""
    wb = load_workbook(path, data_only=True)
    ws = wb.active
    rows = list(ws.iter_rows(values_only=True))
    if not rows:
        return []
    header = [str(c).strip() if c is not None else "" for c in rows[0]]
    idx = {h: i for i, h in enumerate(header)}
    def col(*names):
        for n in names:
            if n in idx:
                return idx[n]
        return None
    c_pn = col("物料编号", "Part Number", "part_number", "编号")
    c_mf = col("型号", "Manufacture", "manufacturer", "规格")
    c_unit = col("单位", "unit")
    c_ss = col("安全库存", "safety_stock", "安全量")
    c_op = col("期初库存", "opening_stock", "期初", "库存")
    out = []
    for r in rows[1:]:
        if c_pn is None or r[c_pn] in (None, ""):
            continue
        pn = str(r[c_pn]).strip()
        if not pn:
            continue
        mf = str(r[c_mf]).strip() if (c_mf is not None and r[c_mf] is not None) else ""
        unit = str(r[c_unit]).strip() if (c_unit is not None and r[c_unit] is not None) else "个"
        ss = _f(r[c_ss]) if c_ss is not None else 0
        op = _f(r[c_op]) if c_op is not None else 0
        out.append({
            "part_number": pn, "manufacturer": mf,
            "unit": unit or "个", "safety_stock": ss, "opening_stock": op,
        })
    return out


def import_materials(rows, operator="导入", factory_id=None):
    """upsert 物料; opening_stock>0 写入一条"期初"入库流水。返回 (新增, 更新)"""
    added = 0
    updated = 0
    for d in rows:
        m = db.session.scalar(db.select(Material).where(Material.part_number == d["part_number"]))
        if m is None:
            m = Material(part_number=d["part_number"], manufacturer=d.get("manufacturer", ""),
                         unit=d.get("unit", "个"), safety_stock=d.get("safety_stock", 0))
            db.session.add(m)
            db.session.flush()
            added += 1
        else:
            m.manufacturer = d.get("manufacturer", m.manufacturer)
            m.unit = d.get("unit", m.unit) or "个"
            m.safety_stock = d.get("safety_stock", m.safety_stock)
            updated += 1
        op = d.get("opening_stock", 0) or 0
        if op > 0:
            exists = db.session.scalar(
                db.select(Inbound).where(Inbound.material_id == m.id, Inbound.source == "期初",
                                         Inbound.factory_id == factory_id))
            if exists:
                exists.qty = op
            else:
                db.session.add(Inbound(material_id=m.id, factory_id=factory_id, qty=op, source="期初",
                                       occur_date=date.today(), operator=operator))
    db.session.commit()
    return added, updated


# ---------------- BOM ----------------
def read_bom(path):
    """返回 {code, name, items:[{part_number, qty_per_unit}]} 或 None(格式不符)"""
    wb = load_workbook(path, data_only=True)
    ws = wb.active
    rows = list(ws.iter_rows(values_only=True))
    if not rows:
        return None
    header = [str(c).strip() if c is not None else "" for c in rows[0]]
    idx = {h: i for i, h in enumerate(header)}
    def col(*names):
        for n in names:
            if n in idx:
                return idx[n]
        return None
    c_code = col("BOM型号", "code", "BOM")
    c_name = col("名称", "name", "产品")
    c_pn = col("物料编号", "Part Number", "part_number", "编号")
    c_qty = col("单套用量", "qty_per_unit", "用量")
    if c_code is None or c_pn is None or c_qty is None:
        return None
    code = str(rows[1][c_code]).strip() if rows[1][c_code] else ""
    name = str(rows[1][c_name]).strip() if (c_name is not None and rows[1][c_name]) else ""
    items = []
    for r in rows[1:]:
        if r[c_pn] in (None, ""):
            continue
        pn = str(r[c_pn]).strip()
        q = _f(r[c_qty])
        if q <= 0:
            continue
        items.append({"part_number": pn, "qty_per_unit": q})
    return {"code": code, "name": name, "items": items}


def import_bom(data, operator="导入", auto_create=False):
    """写入 BOM + BomItem。

    auto_create=True 时, 物料主数据不存在则按 Part Number + Manufacture 自动新建(便于真实 BOM 一步导入);
    否则物料不存在则该项被跳过。返回 (bom_id, 成功项, 跳过项, 自动新建物料数)。
    """
    if not data or not data["code"]:
        return None, 0, 0, 0
    bom = db.session.scalar(db.select(Bom).where(Bom.code == data["code"]))
    if bom is None:
        bom = Bom(code=data["code"], name=data.get("name", ""))
        db.session.add(bom)
        db.session.flush()
    else:
        db.session.execute(db.delete(BomItem).where(BomItem.bom_id == bom.id))
    ok = 0
    skip = 0
    created_mat = 0
    for it in data["items"]:
        pn = str(it["part_number"]).strip()
        m = db.session.scalar(db.select(Material).where(Material.part_number == pn))
        if m is None:
            if not auto_create:
                skip += 1
                continue
            m = Material(part_number=pn,
                         manufacturer=str(it.get("manufacture", "") or "").strip(),
                         unit="个")
            db.session.add(m)
            db.session.flush()
            created_mat += 1
        db.session.add(BomItem(bom_id=bom.id, material_id=m.id, qty_per_unit=it["qty_per_unit"]))
        ok += 1
    db.session.commit()
    return bom.id, ok, skip, created_mat


# ---------------- 导出 ----------------
def export_inventory(path, rows):
    """rows: [{m, stock, status}]"""
    wb = Workbook()
    ws = wb.active
    ws.title = "库存"
    head = ["物料编号", "型号/规格", "单位", "在库数量", "安全库存", "状态"]
    ws.append(head)
    for c in ws[1]:
        c.font = Font(bold=True)
        c.fill = PatternFill("solid", fgColor="DDEBF7")
    for r in rows:
        m = r["m"]
        status = {"ok": "正常", "warn": "低于安全库存", "danger": "库存为负"}[r["status"]]
        ws.append([m.part_number, m.manufacturer, m.unit, r["stock"],
                   m.safety_stock or 0, status])
        if r["status"] == "danger":
            ws.cell(row=ws.max_row, column=4).fill = PatternFill("solid", fgColor="F8CBAD")
        elif r["status"] == "warn":
            ws.cell(row=ws.max_row, column=4).fill = PatternFill("solid", fgColor="FFE699")
    ws.freeze_panes = "A2"
    wb.save(path)


def export_prep(path, rows, scope=""):
    """导出备料清单(采购下单用, 不记账; 手工维护, 与生产订单无关)。

    rows: [{id, m, plan(计划数量), stock(实际库存), diff(缺口=计划-库存), short}]
    scope: 范围说明(工厂/全部)。
    """
    wb = Workbook()
    ws = wb.active
    ws.title = "备料清单"
    head = ["物料编号", "型号/规格", "单位", "计划数量", "实际库存",
            "缺口(计划-库存)", "状态", "范围"]
    ws.append(head)
    for c in ws[1]:
        c.font = Font(bold=True)
        c.fill = PatternFill("solid", fgColor="DDEBF7")
    for r in rows:
        m = r["m"]
        status = "需采购" if r["diff"] > 0 else ("刚好够" if r["diff"] == 0 else "已有盈余")
        ws.append([m.part_number, m.manufacturer or "", m.unit or "个",
                   r["plan"], r["stock"], r["diff"], status, scope])
        # 缺口着色: >0 需采购标红; <0 盈余标绿
        if r["diff"] > 0:
            ws.cell(row=ws.max_row, column=6).fill = PatternFill("solid", fgColor="FFC7CE")
        elif r["diff"] < 0:
            ws.cell(row=ws.max_row, column=6).fill = PatternFill("solid", fgColor="C6EFCE")
    ws.freeze_panes = "A2"
    wb.save(path)


def build_material_template(path):
    wb = Workbook()
    ws = wb.active
    ws.append(["物料编号", "型号/规格", "单位", "安全库存", "期初库存"])
    for c in ws[1]:
        c.font = Font(bold=True)
    ws.append(["P0001", "示例型号A", "个", "100", "500"])
    ws.append(["P0002", "示例型号B", "卷", "50", "200"])
    wb.save(path)
    return path


def export_ledger(target, rows):
    """导出流水台账。target 可为路径或文件对象(如 BytesIO)。

    rows: _build_ledger_rows() 返回的流水行列表, 每项含
    date/type/cat/m/qty/fac/who/ref/op 字段。
    """
    wb = Workbook()
    ws = wb.active
    ws.title = "流水台账"
    head = ["日期", "类型", "业务类型", "物料编号", "型号/规格", "单位",
            "数量", "工厂", "来源/用途", "调拨/关联单号", "经手人"]
    ws.append(head)
    for c in ws[1]:
        c.font = Font(bold=True)
        c.fill = PatternFill("solid", fgColor="DDEBF7")
    for r in rows:
        m = r["m"]
        ws.append([
            r["date"].isoformat() if r["date"] else "",
            r["type"],
            r["cat"],
            m.part_number if m else "",
            m.manufacturer if m else "",
            m.unit if m else "",
            r["qty"],
            r["fac"].code if r["fac"] else "",
            r["who"] or "",
            r["ref"] or "",
            r["op"] or "",
        ])
    # 出入着色: 入(绿) / 出(红)
    for i in range(2, ws.max_row + 1):
        tval = ws.cell(row=i, column=2).value
        if tval == "入":
            ws.cell(row=i, column=2).fill = PatternFill("solid", fgColor="C6EFCE")
        elif tval == "出":
            ws.cell(row=i, column=2).fill = PatternFill("solid", fgColor="FFC7CE")
    ws.freeze_panes = "A2"
    wb.save(target)


def build_bom_template(path):
    """生成与真实 BOM 模板一致的格式(Altium/嘉立创导出):
    每个 worksheet 一个 BOM, sheet 名即 BOM 型号; 列头 Item/Part Number/
    Manufacture Part Number/Quantity/Reference/Part/Package。"""
    wb = Workbook()
    ws = wb.active
    ws.title = "示例型号A"
    ws.append(["Item", "Part Number", "Manufacture Part Number",
               "Quantity", "Reference", "Part", "Package"])
    for c in ws[1]:
        c.font = Font(bold=True)
        c.fill = PatternFill("solid", fgColor="DDEBF7")
    ws.append([1, "1001003", "CFW32C7UL_BUA", 1, "U1", "CFW32C7UL_BUA", "CFW32C7UL_IU_SOCKET"])
    ws.append([2, "1003002", "BY25Q32BSSIG", 1, "U2", "GD25Q127CSIG", "SOIC-8-S"])
    ws.append([3, "1007004", "SGM2036-2.5YUDH4G/TR", 1, "U11", "SGM2036-2.5YUDH4G/TR", ""])
    ws.freeze_panes = "A2"
    wb.save(path)
    return path


def _norm(h):
    return str(h or "").strip().lower()


def _find_col(header, names):
    """返回第一个精确匹配或包含匹配的列索引; 精确优先, 避免误命中(如 'part' 命中 'Part Number')"""
    low = [_norm(h) for h in header]
    # 1) 精确匹配
    for n in names:
        nn = _norm(n)
        for i, h in enumerate(low):
            if h == nn:
                return i
    # 2) 包含匹配(子串)
    for n in names:
        nn = _norm(n)
        if not nn:
            continue
        for i, h in enumerate(low):
            if nn in h:
                return i
    return None


def _find_cols(header, names):
    """返回所有匹配的列索引(用于重复表头, 如两个 'Quantity')"""
    low = [_norm(h) for h in header]
    out = []
    for n in names:
        nn = _norm(n)
        if not nn:
            continue
        for i, h in enumerate(low):
            if h == nn or nn in h:
                if i not in out:
                    out.append(i)
    return out


def _f(v):
    try:
        return float(v)
    except (TypeError, ValueError):
        return 0


# ---------------- 批量导入窗口: 文本解析 ----------------
_ITEM_HEADER_RE = re.compile(
    r"物料|编号|part\s?number|型号|manufacture|单位|unit|安全|safety|期初|库存|名称|bom|单套|用量|数量|qty",
    re.I,
)


def parse_materials_text(text):
    """粘贴多行 -> [{part_number, manufacturer, unit, safety_stock, opening_stock}]

    每行格式: 物料编号 型号/规格 单位 安全库存 期初库存
    列之间可用 空格/制表符/逗号/中文逗号 分隔; 首列命中表头关键词的行会被跳过。
    """
    out = []
    for raw in (text or "").split("\n"):
        s = re.sub(r"[\t,，;；]+", " ", raw).strip()
        if not s:
            continue
        parts = s.split()
        if not parts:
            continue
        if _ITEM_HEADER_RE.search(parts[0]):
            continue  # 跳过表头
        pn = parts[0]
        if not pn:
            continue
        mf = parts[1] if len(parts) > 1 else ""
        unit = parts[2] if len(parts) > 2 else "个"
        ss = _f(parts[3]) if len(parts) > 3 else 0
        op = _f(parts[4]) if len(parts) > 4 else 0
        out.append({
            "part_number": pn,
            "manufacturer": mf,
            "unit": unit or "个",
            "safety_stock": ss,
            "opening_stock": op,
        })
    return out


def parse_boms_text(text):
    """粘贴多行(以 #BOM 标记分段) -> [{code, name, items:[{part_number, qty_per_unit}]}]

    格式:
        #BOM M4021 示例产品A
        P0001 2
        P0002 0.5

        #BOM M4022 示例产品B
        P0003 4
    """
    boms = []
    cur = None
    for raw in (text or "").split("\n"):
        s = re.sub(r"[\t,，;；]+", " ", raw).strip()
        if not s:
            continue
        parts = s.split()
        if not parts:
            continue
        is_head = s.startswith("#") or re.match(r"^(BOM|型号|MODEL)\b", parts[0], re.I) is not None
        if is_head:
            body = re.sub(r"^#+\s*", "", s, flags=re.I)
            body = re.sub(r"^(BOM|型号|MODEL)\s*", "", body, flags=re.I).strip()
            bp = body.split()
            if not bp:
                continue
            if len(bp) > 1 and re.search(r"名称|物料|编号|单套|用量|数量", bp[1]):
                continue  # 表头行(如 "BOM型号 名称 物料编号 单套用量")
            cur = {"code": bp[0], "name": " ".join(bp[1:]) if len(bp) > 1 else "", "items": []}
            boms.append(cur)
            continue
        if _ITEM_HEADER_RE.search(parts[0]):
            continue  # 表头行
        if len(parts) < 2:
            continue
        if cur is None:
            continue
        cur["items"].append({"part_number": parts[0], "qty_per_unit": _f(parts[1])})
    return boms


def read_boms_multi(path):
    """Excel/CSV -> [{code, name, items:[{part_number, qty_per_unit, manufacture}]}]

    适配真实 BOM 模板(Altium / 嘉立创 EDA 导出):
      - 每个 worksheet 视为一个 BOM, BOM 型号 = sheet 名
      - 电子料表: 表头含 'Part Number'(物料编号) + 'Quantity'(单套用量, 取第一个 Quantity 列)
      - 组装表:   表头含 '物料代码'(物料编号) + '数量'(单套用量)
      - 兼容旧模板: 若表头含 'BOM型号' 列, 则按该列分组(单 sheet 多 BOM)
    返回的每个 item 带 manufacture(型号/规格), 便于物料不存在时自动建物料。
    """
    if str(path).lower().endswith(".csv"):
        with open(path, newline="", encoding="utf-8-sig") as f:
            rows = [r for r in csv.reader(f)]
        sheets = [("Sheet1", rows)]
    else:
        wb = load_workbook(path, data_only=True)
        sheets = [(ws.title, list(ws.iter_rows(values_only=True))) for ws in wb.worksheets]

    result = []
    for sheet_name, rows in sheets:
        if not rows or len(rows) < 2:
            continue
        header = [str(c).strip() if c is not None else "" for c in rows[0]]
        if not any(header):
            continue
        pn_col = _find_col(header, ["part number", "partnumber", "物料编号", "物料代码"])
        qty_cols = _find_cols(header, ["quantity", "数量", "单套用量", "qty", "qty_per_unit"])
        mf_col = _find_col(header, ["manufacture part number", "manufacture", "型号", "part"])
        code_col = _find_col(header, ["bom型号", "code", "bom"])
        name_col = _find_col(header, ["名称", "name", "产品"])
        if pn_col is None or not qty_cols:
            continue  # 该 sheet 不是物料清单, 跳过(如说明页)
        qty_col = qty_cols[0]  # 取第一个 Quantity 列(嘉立创常出现两个 Quantity)

        items = []
        for r in rows[1:]:
            if not any(c not in (None, "") for c in r):
                continue
            pn = str(r[pn_col]).strip() if pn_col < len(r) and r[pn_col] not in (None, "") else ""
            if not pn:
                continue
            qty = _f(r[qty_col]) if qty_col < len(r) else 0
            # 嘉立创常出现两个 Quantity 列, 若首列空/0 则回退到次列, 避免丢料
            if qty <= 0 and len(qty_cols) > 1 and qty_cols[1] < len(r):
                q2 = _f(r[qty_cols[1]])
                if q2 > 0:
                    qty = q2
            if qty <= 0:
                continue
            mf = ""
            if mf_col is not None and mf_col < len(r) and r[mf_col] not in (None, ""):
                mf = str(r[mf_col]).strip()
            items.append({"part_number": pn, "qty_per_unit": qty, "manufacture": mf})
        if not items:
            continue

        code = sheet_name.strip()
        name = ""
        if code_col is not None:  # 兼容旧模板: 取首行 BOM型号/名称
            for r in rows[1:]:
                if code_col < len(r) and r[code_col] not in (None, ""):
                    code = str(r[code_col]).strip()
                    if name_col is not None and name_col < len(r) and r[name_col] not in (None, ""):
                        name = str(r[name_col]).strip()
                    break
        result.append({"code": code, "name": name, "items": items})
    return result