import re
from typing import Any, Dict, List, Optional, Tuple

import openpyxl

from apps.factory.models import Factory
from apps.material.models import Material


MAJOR_CATEGORY_MAP = {
    "建筑": "architecture",
    "景观": "landscape",
    "设备": "equipment",
    "装修": "decoration",
    "室内": "decoration",
}

STAGE_VALUES = {choice[0] for choice in Material.STAGE_CHOICES}
IMPORTANCE_LEVEL_VALUES = {choice[0] for choice in Material.IMPORTANCE_LEVEL_CHOICES}
UNIT_SPLIT_RE = re.compile(r"[\s,，、/；;]+")


def _cell(value: Any) -> str:
    if value is None:
        return ""
    return str(value).strip()


def _single_line(value: Any, max_len: int = 255) -> str:
    text = _cell(value)
    if not text:
        return ""
    text = re.sub(r"\s+", " ", text)
    return text[:max_len].strip()


def _parse_choice(value: Any, allowed_values: set) -> Optional[str]:
    text = _cell(value)
    if not text:
        return None
    return text if text in allowed_values else None


def _resolve_factory(unit_name: str, factory_cache: Dict[str, Optional[Factory]], unrecognized_factory: Factory) -> Tuple[Factory, bool, bool]:
    if not unit_name:
        return unrecognized_factory, True, False

    if unit_name not in factory_cache:
        candidates = [part.strip() for part in UNIT_SPLIT_RE.split(unit_name) if part.strip()]
        search_terms = candidates or [unit_name]

        matched_factory = None
        for term in search_terms:
            matched_factory = Factory.objects.filter(brand=term).first()
            if matched_factory:
                break
            matched_factory = Factory.objects.filter(brand__icontains=term).first()
            if matched_factory:
                break
            term_lower = term.lower()
            for factory in Factory.objects.all():
                brand = (factory.brand or "").lower()
                if brand and brand in term_lower:
                    matched_factory = factory
                    break
            if matched_factory:
                break

        factory_cache[unit_name] = matched_factory

    factory = factory_cache[unit_name]
    if factory:
        return factory, False, False

    created_factory = Factory.objects.create(
        factory_name=unit_name,
        brand=unit_name,
        province="北京",
        city="北京",
        district="北京",
    )
    factory_cache[unit_name] = created_factory
    return created_factory, False, True


def import_materials_plan_excel(file_obj) -> Dict[str, int]:
    workbook = openpyxl.load_workbook(file_obj, read_only=True, data_only=True)
    worksheet = workbook[workbook.sheetnames[0]]
    rows = list(worksheet.iter_rows(values_only=True))
    workbook.close()

    if len(rows) < 3:
        raise ValueError("Excel 内容不足，未找到表头或数据。")

    header = [_cell(value) for value in rows[1]]
    header_index = {name: idx for idx, name in enumerate(header) if name}

    required_headers = ["材料大类", "细分种类", "材料名称", "材料单位名称"]
    missing_headers = [name for name in required_headers if name not in header_index]
    if missing_headers:
        raise ValueError(f"缺少必要表头: {', '.join(missing_headers)}")

    def get(row: Tuple[Any, ...], key: str) -> str:
        idx = header_index.get(key, -1)
        if idx < 0 or idx >= len(row):
            return ""
        return _cell(row[idx])

    unrecognized_factory, _ = Factory.objects.get_or_create(
        brand="未识别的品牌",
        defaults={
            "factory_name": "未识别的品牌工厂",
            "province": "-",
            "city": "-",
        },
    )

    created = 0
    updated = 0
    skipped = 0
    unresolved_factory = 0
    created_factory = 0
    factory_cache: Dict[str, Optional[Factory]] = {}
    current_major_category = ""

    for row in rows[2:]:
        if not row:
            continue

        row_values = [_cell(value) for value in row]
        if not any(row_values):
            continue

        major_raw = get(row, "材料大类")
        if major_raw:
            current_major_category = major_raw

        material_name = _single_line(get(row, "材料名称"))
        material_category = _single_line(get(row, "细分种类"))
        if not material_name or not material_category or not current_major_category:
            skipped += 1
            continue

        unit_name = get(row, "材料单位名称")
        factory, is_unresolved, is_created_factory = _resolve_factory(unit_name, factory_cache, unrecognized_factory)
        if is_unresolved:
            unresolved_factory += 1
        if is_created_factory:
            created_factory += 1

        defaults = {
            "stage": _parse_choice(get(row, "阶段"), STAGE_VALUES),
            "importance_level": _parse_choice(get(row, "重要等级"), IMPORTANCE_LEVEL_VALUES),
            "landing_project": _single_line(get(row, "落地项目")) or None,
            "contact_person": _single_line(get(row, "对接人")) or None,
            "contact_phone": _single_line(get(row, "对接人联系方式")) or None,
            "handler": _single_line(get(row, "经办人")) or None,
            "remark": _single_line(get(row, "备注")) or None,
            "factory": factory,
        }

        material, created_flag = Material.objects.update_or_create(
            name=material_name,
            major_category=MAJOR_CATEGORY_MAP.get(current_major_category, "architecture"),
            material_category=material_category,
            factory=factory,
            defaults=defaults,
        )

        if created_flag:
            created += 1
        else:
            updated += 1

    return {
        "created": created,
        "updated": updated,
        "skipped": skipped,
        "unresolved_factory": unresolved_factory,
        "created_factory": created_factory,
    }