"""Read-only display geometry from the exact XLSX that will be saved."""
import datetime
import math
import mimetypes
import re
from decimal import Decimal, ROUND_HALF_UP

# Match the travel exporter: the app sandbox cannot read system MIME databases.
mimetypes.knownfiles = []
mimetypes.init()

from openpyxl.styles.colors import COLOR_INDEX
from openpyxl.styles.numbers import BUILTIN_FORMATS, is_date_format
from openpyxl.utils.datetime import from_excel, MAC_EPOCH, WINDOWS_EPOCH

from expense_template import Template, column_name, coordinate, tag, xml

DRAWING = 'http://schemas.openxmlformats.org/drawingml/2006/main'
MAX_CELLS = 50000


def flag(node, name, default=False):
    return node.get(name, '1' if default else '0') in ('1', 'true')


def child_value(node, name, fallback):
    child = node.find(tag(name))
    return child.get('val', fallback) if child is not None else fallback


def theme_colors(template):
    if 'xl/theme/theme1.xml' not in template.parts:
        return ['FFFFFF', '000000', 'EEECE1', '1F497D', '4F81BD', 'C0504D',
                '9BBB59', '8064A2', '4BACC6', 'F79646', '0000FF', '800080']
    scheme = xml(template.parts['xl/theme/theme1.xml']).find('.//{' + DRAWING + '}clrScheme')
    by_name = {entry.tag.split('}')[-1]: entry[0].get('lastClr', entry[0].get('val', '000000'))
               for entry in scheme}
    return [by_name.get(name, '000000') for name in
            ['lt1', 'dk1', 'lt2', 'dk2', 'accent1', 'accent2', 'accent3', 'accent4',
             'accent5', 'accent6', 'hlink', 'folHlink']]


def color(node, palette, fallback='000000'):
    if node is None:
        return fallback
    value = node.get('rgb')
    if value is None and 'theme' in node.attrib:
        value = palette[int(node.get('theme')) % len(palette)]
    if value is None and 'indexed' in node.attrib:
        index = int(node.get('indexed'))
        value = COLOR_INDEX[index] if index < len(COLOR_INDEX) else fallback
    value = (value or fallback)[-6:]
    if not re.fullmatch('[0-9a-fA-F]{6}', value):
        return fallback
    tint = max(-1, min(1, float(node.get('tint', 0))))
    return ''.join(f'{round(channel * (1 + tint) if tint < 0 else channel * (1 - tint) + 255 * tint):02X}'
                   for channel in (int(value[index:index + 2], 16) for index in (0, 2, 4)))


def literal(value):
    return re.sub(r'"([^"]*)"|\\(.)|_.|\*.', lambda m: m[1] or m[2] or '', value)


def formatted(value, kind, code, date_1904, warnings):
    if value == '' or kind in ('s', 'inlineStr', 'str', 'e'):
        return value
    if kind == 'b':
        return 'TRUE' if value == '1' else 'FALSE'
    number = Decimal(value)
    if is_date_format(code):
        date = from_excel(float(number), MAC_EPOCH if date_1904 else WINDOWS_EPOCH)
        if isinstance(date, (datetime.datetime, datetime.time)):
            # Excel date/time tokens are not strftime tokens (notably month/minute).
            section = code.split(';')[0]
            section = re.sub(r'\[[^\]]*\]', '', section)
            section = literal(section)
            if isinstance(date, datetime.datetime) and section.lower() == 'mm-dd-yy':
                return date.strftime('%m-%d-%y')
            if re.fullmatch(r'yyyy([/.-])m{1,2}\1d{1,2}', section, re.I):
                sep = section[4]
                return f'{date.year}{sep}{date.month:02d}{sep}{date.day:02d}' if 'mm' in section.lower() else f'{date.year}{sep}{date.month}{sep}{date.day}'
            if section.lower() in ('yyyy"年"m"月"d"日"', 'yyyy年m月d日'):
                return f'{date.year}年{date.month}月{date.day}日'
            if section.lower() in ('h:mm', 'hh:mm', 'h:mm:ss', 'hh:mm:ss'):
                return date.strftime('%H:%M:%S' if 'ss' in section.lower() else '%H:%M')
            warnings.add('部分日期格式使用标准日期显示')
            return date.date().isoformat() if isinstance(date, datetime.datetime) else date.isoformat()
    if code.lower() in ('general', '@'):
        return format(number, 'f').rstrip('0').rstrip('.') if '.' in str(number) else str(number)
    sections = re.split(r';(?=(?:[^"]*"[^"]*")*[^"]*$)', code)
    section = sections[2] if number == 0 and len(sections) > 2 else sections[1] if number < 0 and len(sections) > 1 else sections[0]
    section = re.sub(r'\[\$([^\]-]*)[^\]]*\]', lambda m: m[1], section)
    if re.search(r'\[(?:[<>=]|\d)', section):
        warnings.add('部分条件数字格式使用原始数值显示')
        return str(number)
    section = re.sub(r'\[[^\]]*\]', '', section)
    # Ignore placeholders inside quoted/escaped literals.
    masked = re.sub(r'"[^"]*"|\\.|_.|\*.', lambda m: ' ' * len(m[0]), section)
    match = re.search(r'[#0][#0,]*(?:\.[#0?]+)?%?', masked)
    if not match:
        return literal(section).strip().replace('?', '')
    if re.search(r'[Ee][+-]|[/]', masked) or masked[match.end():].lstrip().startswith(','):
        warnings.add('部分科学计数或分数格式使用原始数值显示')
        return str(number)
    pattern = match[0]
    places = len(pattern.rstrip('%').split('.')[1]) if '.' in pattern else 0
    value = abs(number) if number < 0 and len(sections) > 1 else number
    if '%' in pattern:
        value *= 100
    value = value.quantize(Decimal(1).scaleb(-places), rounding=ROUND_HALF_UP)
    text = format(value, (',' if ',' in pattern else '') + f'.{places}f')
    if '.' in pattern:
        fraction = pattern.rstrip('%').split('.')[1]
        optional = len(fraction) - len(fraction.rstrip('#?'))
        for _ in range(optional):
            if text.endswith('0'):
                text = text[:-1]
        text = text.rstrip('.')
    if ',' not in pattern and '.' not in pattern:
        text = text.zfill(pattern.count('0'))
    if '%' in pattern:
        text += '%'
    return literal(section[:match.start()]) + text + literal(section[match.end():])


def read_styles(template, palette):
    root = xml(template.parts['xl/styles.xml'])
    fonts, fills, borders = root.find(tag('fonts')), root.find(tag('fills')), root.find(tag('borders'))
    formats = dict(BUILTIN_FORMATS)
    for item in root.findall(tag('numFmts') + '/' + tag('numFmt')):
        formats[int(item.get('numFmtId'))] = item.get('formatCode')
    styles = []
    for entry in root.find(tag('cellXfs')):
        font = fonts[int(entry.get('fontId', 0))]
        fill = fills[int(entry.get('fillId', 0))].find(tag('patternFill'))
        border = borders[int(entry.get('borderId', 0))]
        alignment = entry.find(tag('alignment'))
        if alignment is None:
            alignment = {}
        sides = {}
        for edge in ('left', 'right', 'top', 'bottom'):
            side = border.find(tag(edge))
            if side is not None and side.get('style'):
                sides[edge] = dict(style=side.get('style'), color=color(side.find(tag('color')), palette))
        styles.append(dict(
            font=child_value(font, 'name', 'Calibri'), fontSize=float(child_value(font, 'sz', '11')),
            bold=font.find(tag('b')) is not None and flag(font.find(tag('b')), 'val', True),
            italic=font.find(tag('i')) is not None and flag(font.find(tag('i')), 'val', True),
            underline=font.find(tag('u')) is not None and child_value(font, 'u', 'single') != 'none',
            strike=font.find(tag('strike')) is not None and flag(font.find(tag('strike')), 'val', True),
            color=color(font.find(tag('color')), palette),
            fill=color(fill.find(tag('fgColor')), palette, 'FFFFFF') if fill is not None and fill.get('patternType') == 'solid' else 'FFFFFF',
            horizontal=alignment.get('horizontal', 'general'), vertical=alignment.get('vertical', 'bottom'),
            wrap=alignment.get('wrapText') in ('1', 'true'), shrink=alignment.get('shrinkToFit') in ('1', 'true'),
            rotation=int(alignment.get('textRotation', 0)), indent=float(alignment.get('indent', 0)),
            borders=sides, numberFormat=formats.get(int(entry.get('numFmtId', 0)), 'General')
        ))
    return styles


def read_layout(path):
    template = Template(path)
    palette = theme_colors(template)
    styles = read_styles(template, palette)
    properties = template.workbook.find(tag('workbookPr'))
    date_1904 = properties is not None and flag(properties, 'date1904')
    warnings = set()
    sheets, total_cells = [], 0
    for sheet_index, sheet in enumerate(template.sheets):
        if sheet.get('state', 'visible') != 'visible':
            continue
        name = sheet.get('name')
        _, _, document = template.sheet(name)
        cells = {cell.get('r'): cell for cell in document.iter(tag('c'))}
        merges = [item.get('ref') for item in document.iter(tag('mergeCell'))]
        # Empty formatted tail columns must not squeeze the actual form. Preserve
        # all nonempty cells, even when they are outside the workbook print area.
        references = [ref for ref, cell in cells.items() if cell.find(tag('v')) is not None or
                      cell.find(tag('is')) is not None or cell.find(tag('f')) is not None]
        ranges = []
        for definition in template.workbook.findall(tag('definedNames') + '/' + tag('definedName')):
            if definition.get('name') == '_xlnm.Print_Area' and definition.get('localSheetId') == str(sheet_index):
                ranges += re.findall(r'\$?([A-Z]+)\$?(\d+):\$?([A-Z]+)\$?(\d+)', definition.text or '')
        references += [f'{c}{r}' for a, b, c, r in ranges]
        references += [entry.split(':')[-1] for entry in merges]
        if not references:
            references = list(cells) or ['A1']
        positions = [coordinate(ref) for ref in references]
        columns, rows = max(p[0] for p in positions), max(p[1] for p in positions)
        if columns * rows > MAX_CELLS or total_cells + len(cells) > MAX_CELLS:
            raise ValueError('模板范围过大，无法完整预览；请精简模板后重试')
        total_cells += len(cells)
        defaults = document.find(tag('sheetFormatPr'))
        default_width = float(defaults.get('defaultColWidth', 8.43)) if defaults is not None else 8.43
        default_height = float(defaults.get('defaultRowHeight', 15)) if defaults is not None else 15
        widths = [default_width] * columns
        heights = [default_height] * rows
        for column in document.findall(tag('cols') + '/' + tag('col')):
            for index in range(int(column.get('min')) - 1, min(columns, int(column.get('max')))):
                widths[index] = 0 if flag(column, 'hidden') else float(column.get('width', default_width))
        for row in document.findall(tag('sheetData') + '/' + tag('row')):
            index = int(row.get('r')) - 1
            if index < rows:
                heights[index] = 0 if flag(row, 'hidden') else float(row.get('ht', default_height))
        # OOXML width is expressed in maximum-digit units. Geometry is kept at
        # 96 dpi; Swift scales the complete sheet, never individual columns.
        widths = [math.floor(((256 * width + 18) / 256) * 7) for width in widths]
        heights = [height * 4 / 3 for height in heights]
        xs, ys = [0], [0]
        for width in widths:
            xs.append(xs[-1] + width)
        for height in heights:
            ys.append(ys[-1] + height)
        covered, spans = set(), {}
        for merged in merges:
            first, last = merged.split(':')
            left, top = coordinate(first)
            right, bottom = coordinate(last)
            spans[first] = (right, bottom)
            covered.update((col, row) for col in range(left, right + 1) for row in range(top, bottom + 1)
                           if (col, row) != (left, top))
        output = []
        occupied = {coordinate(ref) for ref, cell in cells.items()
                    if cell.find(tag('v')) is not None or cell.find(tag('is')) is not None
                    or cell.find(tag('f')) is not None}
        occupied.update(covered)
        occupied.update(coordinate(ref) for ref in spans)
        for reference, cell in cells.items():
            col, row = coordinate(reference)
            if col > columns or row > rows or (col, row) in covered:
                continue
            right, bottom = spans.get(reference, (col, row))
            style = int(cell.get('s', 0))
            appearance = dict(styles[style])
            appearance['borders'] = dict(appearance['borders'])
            # Merged right/bottom edges may be stored on the last cell.
            for edge, edge_ref in [('right', column_name(right) + str(row)),
                                   ('bottom', column_name(col) + str(bottom)),
                                   ('right', column_name(right) + str(bottom)),
                                   ('bottom', column_name(right) + str(bottom))]:
                if edge not in appearance['borders'] and edge_ref in cells:
                    candidate = styles[int(cells[edge_ref].get('s', 0))]['borders'].get(edge)
                    if candidate:
                        appearance['borders'][edge] = candidate
            kind = cell.get('t', 'n')
            value = cell.findtext(tag('v'), '')
            if kind == 's':
                value = template.shared[int(value)] if value else ''
            elif kind == 'inlineStr':
                value = ''.join(node.text or '' for node in cell.iter(tag('t')))
            text = formatted(value, kind, appearance['numberFormat'], date_1904, warnings)
            if appearance['horizontal'] == 'general':
                appearance['horizontal'] = 'right' if kind == 'n' else 'center' if kind == 'b' else 'left'
            width, height = xs[right] - xs[col - 1], ys[bottom] - ys[row - 1]
            if width > 0 and height > 0:
                left_limit, right_limit = col, right
                if (text and kind in ('s', 'inlineStr', 'str') and reference not in spans
                        and not appearance['wrap'] and not appearance['shrink'] and appearance['rotation'] == 0):
                    if appearance['horizontal'] in ('left', 'center'):
                        while right_limit < columns and (right_limit + 1, row) not in occupied:
                            right_limit += 1
                    if appearance['horizontal'] in ('right', 'center'):
                        while left_limit > 1 and (left_limit - 1, row) not in occupied:
                            left_limit -= 1
                output.append(dict(reference=reference, x=xs[col - 1], y=ys[row - 1], width=width, height=height,
                                   text=text, style=appearance,
                                   overflowLeft=xs[left_limit - 1], overflowRight=xs[right_limit]))
        for feature in ('drawing', 'legacyDrawing', 'conditionalFormatting'):
            if document.find(tag(feature)) is not None:
                warnings.add('模板中的图片、图表或条件格式请在 Excel / WPS 中核对')
        sheets.append(dict(name=name, width=max(1, xs[-1]), height=max(1, ys[-1]), cells=output))
    return dict(version=1, sheets=sheets, warnings=sorted(warnings))