"""The |Table| object and related proxy classes."""

from __future__ import annotations

from typing import List, Tuple, overload

from docx.blkcntnr import BlockItemContainer
from docx.enum.style import WD_STYLE_TYPE
from docx.oxml.simpletypes import ST_Merge
from docx.shared import Inches, Parented, lazyproperty


class Table(Parented):
    """Proxy class for a WordprocessingML ``<w:tbl>`` element."""

    def __init__(self, tbl, parent):
        super(Table, self).__init__(parent)
        self._element = self._tbl = tbl

    def add_column(self, width):
        """Return a |_Column| object of `width`, newly added rightmost to the table."""
        tblGrid = self._tbl.tblGrid
        gridCol = tblGrid.add_gridCol()
        gridCol.w = width
        for tr in self._tbl.tr_lst:
            tc = tr.add_tc()
            tc.width = width
        return _Column(gridCol, self)

    def add_row(self):
        """Return a |_Row| instance, newly added bottom-most to the table."""
        tbl = self._tbl
        tr = tbl.add_tr()
        for gridCol in tbl.tblGrid.gridCol_lst:
            tc = tr.add_tc()
            tc.width = gridCol.w
        return _Row(tr, self)

    @property
    def alignment(self):
        """Read/write.

        A member of :ref:`WdRowAlignment` or None, specifying the positioning of this
        table between the page margins. |None| if no setting is specified, causing the
        effective value to be inherited from the style hierarchy.
        """
        return self._tblPr.alignment

    @alignment.setter
    def alignment(self, value):
        self._tblPr.alignment = value

    @property
    def autofit(self):
        """|True| if column widths can be automatically adjusted to improve the fit of
        cell contents.

        |False| if table layout is fixed. Column widths are adjusted in either case if
        total column width exceeds page width. Read/write boolean.
        """
        return self._tblPr.autofit

    @autofit.setter
    def autofit(self, value):
        self._tblPr.autofit = value

    def cell(self, row_idx, col_idx):
        """Return |_Cell| instance correponding to table cell at `row_idx`, `col_idx`
        intersection, where (0, 0) is the top, left-most cell."""
        cell_idx = col_idx + (row_idx * self._column_count)
        return self._cells[cell_idx]

    def column_cells(self, column_idx):
        """Sequence of cells in the column at `column_idx` in this table."""
        cells = self._cells
        idxs = range(column_idx, len(cells), self._column_count)
        return [cells[idx] for idx in idxs]

    @lazyproperty
    def columns(self):
        """|_Columns| instance representing the sequence of columns in this table."""
        return _Columns(self._tbl, self)

    def row_cells(self, row_idx):
        """Sequence of cells in the row at `row_idx` in this table."""
        column_count = self._column_count
        start = row_idx * column_count
        end = start + column_count
        return self._cells[start:end]

    @lazyproperty
    def rows(self) -> _Rows:
        """|_Rows| instance containing the sequence of rows in this table."""
        return _Rows(self._tbl, self)

    @property
    def style(self):
        """Read/write. A |_TableStyle| object representing the style applied to this
        table. The default table style for the document (often `Normal Table`) is
        returned if the table has no directly-applied style. Assigning |None| to this
        property removes any directly-applied table style causing it to inherit the
        default table style of the document. Note that the style name of a table style
        differs slightly from that.

        displayed in the user interface; a hyphen, if it appears, must be removed. For
        example, `Light Shading - Accent 1` becomes `Light Shading Accent 1`.
        """
        style_id = self._tbl.tblStyle_val
        return self.part.get_style(style_id, WD_STYLE_TYPE.TABLE)

    @style.setter
    def style(self, style_or_name):
        style_id = self.part.get_style_id(style_or_name, WD_STYLE_TYPE.TABLE)
        self._tbl.tblStyle_val = style_id

    @property
    def table(self):
        """Provide child objects with reference to the |Table| object they belong to,
        without them having to know their direct parent is a |Table| object.

        This is the terminus of a series of `parent._table` calls from an arbitrary
        child through its ancestors.
        """
        return self

    @property
    def table_direction(self):
        """A member of :ref:`WdTableDirection` indicating the direction in which the
        table cells are ordered, e.g. `WD_TABLE_DIRECTION.LTR`.

        |None| indicates the value is inherited from the style hierarchy.
        """
        return self._element.bidiVisual_val

    @table_direction.setter
    def table_direction(self, value):
        self._element.bidiVisual_val = value

    @property
    def _cells(self):
        """A sequence of |_Cell| objects, one for each cell of the layout grid.

        If the table contains a span, one or more |_Cell| object references are
        repeated.
        """
        col_count = self._column_count
        cells = []
        for tc in self._tbl.iter_tcs():
            for grid_span_idx in range(tc.grid_span):
                if tc.vMerge == ST_Merge.CONTINUE:
                    cells.append(cells[-col_count])
                elif grid_span_idx > 0:
                    cells.append(cells[-1])
                else:
                    cells.append(_Cell(tc, self))
        return cells

    @property
    def _column_count(self):
        """The number of grid columns in this table."""
        return self._tbl.col_count

    @property
    def _tblPr(self):
        return self._tbl.tblPr


class _Cell(BlockItemContainer):
    """Table cell."""

    def __init__(self, tc, parent):
        super(_Cell, self).__init__(tc, parent)
        self._tc = self._element = tc

    def add_paragraph(self, text="", style=None):
        """Return a paragraph newly added to the end of the content in this cell.

        If present, `text` is added to the paragraph in a single run. If specified, the
        paragraph style `style` is applied. If `style` is not specified or is |None|,
        the result is as though the 'Normal' style was applied. Note that the formatting
        of text in a cell can be influenced by the table style. `text` can contain tab
        (``\\t``) characters, which are converted to the appropriate XML form for a tab.
        `text` can also include newline (``\\n``) or carriage return (``\\r``)
        characters, each of which is converted to a line break.
        """
        return super(_Cell, self).add_paragraph(text, style)

    def add_table(self, rows, cols):
        """Return a table newly added to this cell after any existing cell content,
        having `rows` rows and `cols` columns.

        An empty paragraph is added after the table because Word requires a paragraph
        element as the last element in every cell.
        """
        width = self.width if self.width is not None else Inches(1)
        table = super(_Cell, self).add_table(rows, cols, width)
        self.add_paragraph()
        return table

    def merge(self, other_cell):
        """Return a merged cell created by spanning the rectangular region having this
        cell and `other_cell` as diagonal corners.

        Raises |InvalidSpanError| if the cells do not define a rectangular region.
        """
        tc, tc_2 = self._tc, other_cell._tc
        merged_tc = tc.merge(tc_2)
        return _Cell(merged_tc, self._parent)

    @property
    def paragraphs(self):
        """List of paragraphs in the cell.

        A table cell is required to contain at least one block-level element and end
        with a paragraph. By default, a new cell contains a single paragraph. Read-only
        """
        return super(_Cell, self).paragraphs

    @property
    def tables(self):
        """List of tables in the cell, in the order they appear.

        Read-only.
        """
        return super(_Cell, self).tables

    @property
    def text(self) -> str:
        """The entire contents of this cell as a string of text.

        Assigning a string to this property replaces all existing content with a single
        paragraph containing the assigned text in a single run.
        """
        return "\n".join(p.text for p in self.paragraphs)

    @text.setter
    def text(self, text):
        """Write-only.

        Set entire contents of cell to the string `text`. Any existing content or
        revisions are replaced.
        """
        tc = self._tc
        tc.clear_content()
        p = tc.add_p()
        r = p.add_r()
        r.text = text

    @property
    def vertical_alignment(self):
        """Member of :ref:`WdCellVerticalAlignment` or None.

        A value of |None| indicates vertical alignment for this cell is inherited.
        Assigning |None| causes any explicitly defined vertical alignment to be removed,
        restoring inheritance.
        """
        tcPr = self._element.tcPr
        if tcPr is None:
            return None
        return tcPr.vAlign_val

    @vertical_alignment.setter
    def vertical_alignment(self, value):
        tcPr = self._element.get_or_add_tcPr()
        tcPr.vAlign_val = value

    @property
    def width(self):
        """The width of this cell in EMU, or |None| if no explicit width is set."""
        return self._tc.width

    @width.setter
    def width(self, value):
        self._tc.width = value


class _Column(Parented):
    """Table column."""

    def __init__(self, gridCol, parent):
        super(_Column, self).__init__(parent)
        self._gridCol = gridCol

    @property
    def cells(self):
        """Sequence of |_Cell| instances corresponding to cells in this column."""
        return tuple(self.table.column_cells(self._index))

    @property
    def table(self):
        """Reference to the |Table| object this column belongs to."""
        return self._parent.table

    @property
    def width(self):
        """The width of this column in EMU, or |None| if no explicit width is set."""
        return self._gridCol.w

    @width.setter
    def width(self, value):
        self._gridCol.w = value

    @property
    def _index(self):
        """Index of this column in its table, starting from zero."""
        return self._gridCol.gridCol_idx


class _Columns(Parented):
    """Sequence of |_Column| instances corresponding to the columns in a table.

    Supports ``len()``, iteration and indexed access.
    """

    def __init__(self, tbl, parent):
        super(_Columns, self).__init__(parent)
        self._tbl = tbl

    def __getitem__(self, idx):
        """Provide indexed access, e.g. 'columns[0]'."""
        try:
            gridCol = self._gridCol_lst[idx]
        except IndexError:
            msg = "column index [%d] is out of range" % idx
            raise IndexError(msg)
        return _Column(gridCol, self)

    def __iter__(self):
        for gridCol in self._gridCol_lst:
            yield _Column(gridCol, self)

    def __len__(self):
        return len(self._gridCol_lst)

    @property
    def table(self):
        """Reference to the |Table| object this column collection belongs to."""
        return self._parent.table

    @property
    def _gridCol_lst(self):
        """Sequence containing ``<w:gridCol>`` elements for this table, each
        representing a table column."""
        tblGrid = self._tbl.tblGrid
        return tblGrid.gridCol_lst


class _Row(Parented):
    """Table row."""

    def __init__(self, tr, parent):
        super(_Row, self).__init__(parent)
        self._tr = self._element = tr

    @property
    def cells(self) -> Tuple[_Cell]:
        """Sequence of |_Cell| instances corresponding to cells in this row."""
        return tuple(self.table.row_cells(self._index))

    @property
    def height(self):
        """Return a |Length| object representing the height of this cell, or |None| if
        no explicit height is set."""
        return self._tr.trHeight_val

    @height.setter
    def height(self, value):
        self._tr.trHeight_val = value

    @property
    def height_rule(self):
        """Return the height rule of this cell as a member of the :ref:`WdRowHeightRule`
        enumeration, or |None| if no explicit height_rule is set."""
        return self._tr.trHeight_hRule

    @height_rule.setter
    def height_rule(self, value):
        self._tr.trHeight_hRule = value

    @property
    def table(self):
        """Reference to the |Table| object this row belongs to."""
        return self._parent.table

    @property
    def _index(self):
        """Index of this row in its table, starting from zero."""
        return self._tr.tr_idx


class _Rows(Parented):
    """Sequence of |_Row| objects corresponding to the rows in a table.

    Supports ``len()``, iteration, indexed access, and slicing.
    """

    def __init__(self, tbl, parent):
        super(_Rows, self).__init__(parent)
        self._tbl = tbl

    @overload
    def __getitem__(self, idx: int) -> _Row:
        ...

    @overload
    def __getitem__(self, idx: slice) -> List[_Row]:
        ...

    def __getitem__(self, idx: int | slice) -> _Row | List[_Row]:
        """Provide indexed access, (e.g. `rows[0]` or `rows[1:3]`)"""
        return list(self)[idx]

    def __iter__(self):
        return (_Row(tr, self) for tr in self._tbl.tr_lst)

    def __len__(self):
        return len(self._tbl.tr_lst)

    @property
    def table(self):
        """Reference to the |Table| object this row collection belongs to."""
        return self._parent.table
