from collections import defaultdict
import datetime
from typing import Any, DefaultDict, Dict, List, Optional, Tuple, Union

import pandas._libs.json as json

from pandas.io.excel._base import ExcelWriter
from pandas.io.excel._util import _validate_freeze_panes
from pandas.io.formats.excel import ExcelCell


class _ODSWriter(ExcelWriter):
    engine = "odf"
    supported_extensions = (".ods",)

    def __init__(
        self, path: str, engine: Optional[str] = None, mode: str = "w", **engine_kwargs
    ):
        from odf.opendocument import OpenDocumentSpreadsheet

        engine_kwargs["engine"] = engine

        if mode == "a":
            raise ValueError("Append mode is not supported with odf!")

        super().__init__(path, mode=mode, **engine_kwargs)

        self.book: OpenDocumentSpreadsheet = OpenDocumentSpreadsheet()
        self._style_dict: Dict[str, str] = {}

    def save(self) -> None:
        """
        Save workbook to disk.
        """
        for sheet in self.sheets.values():
            self.book.spreadsheet.addElement(sheet)
        self.book.save(self.path)

    def write_cells(
        self,
        cells: List[ExcelCell],
        sheet_name: Optional[str] = None,
        startrow: int = 0,
        startcol: int = 0,
        freeze_panes: Optional[List] = None,
    ) -> None:
        """
        Write the frame cells using odf
        """
        from odf.table import Table, TableCell, TableRow
        from odf.text import P

        sheet_name = self._get_sheet_name(sheet_name)
        assert sheet_name is not None

        if sheet_name in self.sheets:
            wks = self.sheets[sheet_name]
        else:
            wks = Table(name=sheet_name)
            self.sheets[sheet_name] = wks

        if _validate_freeze_panes(freeze_panes):
            assert freeze_panes is not None
            self._create_freeze_panes(sheet_name, freeze_panes)

        for _ in range(startrow):
            wks.addElement(TableRow())

        rows: DefaultDict = defaultdict(TableRow)
        col_count: DefaultDict = defaultdict(int)

        for cell in sorted(cells, key=lambda cell: (cell.row, cell.col)):
            # only add empty cells if the row is still empty
            if not col_count[cell.row]:
                for _ in range(startcol):
                    rows[cell.row].addElement(TableCell())

            # fill with empty cells if needed
            for _ in range(cell.col - col_count[cell.row]):
                rows[cell.row].addElement(TableCell())
                col_count[cell.row] += 1

            pvalue, tc = self._make_table_cell(cell)
            rows[cell.row].addElement(tc)
            col_count[cell.row] += 1
            p = P(text=pvalue)
            tc.addElement(p)

        # add all rows to the sheet
        for row_nr in range(max(rows.keys()) + 1):
            wks.addElement(rows[row_nr])

    def _make_table_cell_attributes(self, cell) -> Dict[str, Union[int, str]]:
        """Convert cell attributes to OpenDocument attributes

        Parameters
        ----------
        cell : ExcelCell
            Spreadsheet cell data

        Returns
        -------
        attributes : Dict[str, Union[int, str]]
            Dictionary with attributes and attribute values
        """
        attributes: Dict[str, Union[int, str]] = {}
        style_name = self._process_style(cell.style)
        if style_name is not None:
            attributes["stylename"] = style_name
        if cell.mergestart is not None and cell.mergeend is not None:
            attributes["numberrowsspanned"] = max(1, cell.mergestart)
            attributes["numbercolumnsspanned"] = cell.mergeend
        return attributes

    def _make_table_cell(self, cell) -> Tuple[str, Any]:
        """Convert cell data to an OpenDocument spreadsheet cell

        Parameters
        ----------
        cell : ExcelCell
            Spreadsheet cell data

        Returns
        -------
        pvalue, cell : Tuple[str, TableCell]
            Display value, Cell value
        """
        from odf.table import TableCell

        attributes = self._make_table_cell_attributes(cell)
        val, fmt = self._value_with_fmt(cell.val)
        pvalue = value = val
        if isinstance(val, bool):
            value = str(val).lower()
            pvalue = str(val).upper()
        if isinstance(val, datetime.datetime):
            value = val.isoformat()
            pvalue = val.strftime("%c")
            return (
                pvalue,
                TableCell(valuetype="date", datevalue=value, attributes=attributes),
            )
        elif isinstance(val, datetime.date):
            value = val.strftime("%Y-%m-%d")
            pvalue = val.strftime("%x")
            return (
                pvalue,
                TableCell(valuetype="date", datevalue=value, attributes=attributes),
            )
        else:
            class_to_cell_type = {
                str: "string",
                int: "float",
                float: "float",
                bool: "boolean",
            }
            return (
                pvalue,
                TableCell(
                    valuetype=class_to_cell_type[type(val)],
                    value=value,
                    attributes=attributes,
                ),
            )

    def _process_style(self, style: Dict[str, Any]) -> str:
        """Convert a style dictionary to a OpenDocument style sheet

        Parameters
        ----------
        style : Dict
            Style dictionary

        Returns
        -------
        style_key : str
            Unique style key for for later reference in sheet
        """
        from odf.style import (
            ParagraphProperties,
            Style,
            TableCellProperties,
            TextProperties,
        )

        if style is None:
            return None
        style_key = json.dumps(style)
        if style_key in self._style_dict:
            return self._style_dict[style_key]
        name = f"pd{len(self._style_dict)+1}"
        self._style_dict[style_key] = name
        odf_style = Style(name=name, family="table-cell")
        if "font" in style:
            font = style["font"]
            if font.get("bold", False):
                odf_style.addElement(TextProperties(fontweight="bold"))
        if "borders" in style:
            borders = style["borders"]
            for side, thickness in borders.items():
                thickness_translation = {"thin": "0.75pt solid #000000"}
                odf_style.addElement(
                    TableCellProperties(
                        attributes={f"border{side}": thickness_translation[thickness]}
                    )
                )
        if "alignment" in style:
            alignment = style["alignment"]
            horizontal = alignment.get("horizontal")
            if horizontal:
                odf_style.addElement(ParagraphProperties(textalign=horizontal))
            vertical = alignment.get("vertical")
            if vertical:
                odf_style.addElement(TableCellProperties(verticalalign=vertical))
        self.book.styles.addElement(odf_style)
        return name

    def _create_freeze_panes(self, sheet_name: str, freeze_panes: List[int]) -> None:
        """Create freeze panes in the sheet

        Parameters
        ----------
        sheet_name : str
            Name of the spreadsheet
        freeze_panes : list
            Freeze pane location x and y
        """
        from odf.config import (
            ConfigItem,
            ConfigItemMapEntry,
            ConfigItemMapIndexed,
            ConfigItemMapNamed,
            ConfigItemSet,
        )

        config_item_set = ConfigItemSet(name="ooo:view-settings")
        self.book.settings.addElement(config_item_set)

        config_item_map_indexed = ConfigItemMapIndexed(name="Views")
        config_item_set.addElement(config_item_map_indexed)

        config_item_map_entry = ConfigItemMapEntry()
        config_item_map_indexed.addElement(config_item_map_entry)

        config_item_map_named = ConfigItemMapNamed(name="Tables")
        config_item_map_entry.addElement(config_item_map_named)

        config_item_map_entry = ConfigItemMapEntry(name=sheet_name)
        config_item_map_named.addElement(config_item_map_entry)

        config_item_map_entry.addElement(
            ConfigItem(name="HorizontalSplitMode", type="short", text="2")
        )
        config_item_map_entry.addElement(
            ConfigItem(name="VerticalSplitMode", type="short", text="2")
        )
        config_item_map_entry.addElement(
            ConfigItem(
                name="HorizontalSplitPosition", type="int", text=str(freeze_panes[0])
            )
        )
        config_item_map_entry.addElement(
            ConfigItem(
                name="VerticalSplitPosition", type="int", text=str(freeze_panes[1])
            )
        )
        config_item_map_entry.addElement(
            ConfigItem(name="PositionRight", type="int", text=str(freeze_panes[0]))
        )
        config_item_map_entry.addElement(
            ConfigItem(name="PositionBottom", type="int", text=str(freeze_panes[1]))
        )