import type { Column, CssStyleHash, ExcelCopyBufferOption, ExternalCopyClipCommand, SlickPlugin } from '../models/index.js';
import type { SlickGrid } from '../slick.grid.js';
import { SlickEvent as SlickEvent_, type SlickEventData, SlickEventHandler as SlickEventHandler_, SlickRange as SlickRange_, Utils as Utils_ } from '../slick.core.js';

// for (iife) load Slick methods from global Slick object, or use imports for (esm)
const SlickEvent = IIFE_ONLY ? Slick.Event : SlickEvent_;
const SlickEventHandler = IIFE_ONLY ? Slick.EventHandler : SlickEventHandler_;
const SlickRange = IIFE_ONLY ? Slick.Range : SlickRange_;
const Utils = IIFE_ONLY ? Slick.Utils : Utils_;

const CLEAR_COPY_SELECTION_DELAY = 2000;

/***
  This manager enables users to copy/paste data from/to an external Spreadsheet application
  such as MS-Excel® or OpenOffice-Spreadsheet.

  The clipboard transport is the asynchronous Clipboard API (navigator.clipboard),
  which requires a secure context (https or localhost) and, for paste, the browser's
  clipboard-read permission. The clipboardWriteOverride/clipboardReadOverride options
  replace the transport for environments where the Clipboard API is unavailable or the
  host application manages the clipboard itself.

  options:
    copiedCellStyle : sets the css className used for copied cells. default : "copied"
    copiedCellStyleLayerKey : sets the layer key for setting css values of copied cells. default : "copy-manager"
    dataItemColumnValueExtractor : option to specify a custom column value extractor function
    dataItemColumnValueSetter : option to specify a custom column value setter function
    clipboardCommandHandler : option to specify a custom handler for paste actions
    includeHeaderWhenCopying : set to true and the plugin will take the name property from each column (which is usually what appears in your header) and put that as the first row of the text that's copied to the clipboard
    clipboardWriteOverride: option to replace the default clipboard write (navigator.clipboard.writeText) with a custom function
    clipboardReadOverride: option to replace the default clipboard read (navigator.clipboard.readText) with a custom function
    onCopyInit: optional handler to run when copy action initializes
    onCopySuccess: optional handler to run when copy action is complete
    newRowCreator: function to add rows to table if paste overflows bottom of table, if this function is not provided new rows will be ignored.
    readOnlyMode: suppresses paste
    headerColumnValueExtractor : option to specify a custom column header value extractor function
*/
export class SlickCellExternalCopyManager implements SlickPlugin {
  // --
  // public API
  pluginName = 'CellExternalCopyManager' as const;
  onCopyCells = new SlickEvent<{ ranges: SlickRange_[]; }>('onCopyCells');
  onCopyCancelled = new SlickEvent<{ ranges: SlickRange_[]; }>('onCopyCancelled');
  onPasteCells = new SlickEvent<{ ranges: SlickRange_[]; }>('onPasteCells');

  // --
  // protected props
  protected _eventHandler = new SlickEventHandler();
  protected _grid!: SlickGrid;
  protected _copiedRanges: SlickRange_[] | null = null;
  protected _clearCopyTI?: number;
  protected _copiedCellStyle: string;
  protected _copiedCellStyleLayerKey: string;
  protected _onCopyInit?: () => void;
  protected _onCopySuccess?: (rowCount: number) => void;
  protected _options: ExcelCopyBufferOption;

  constructor(options: ExcelCopyBufferOption) {
    this._options = options || {};
    this._copiedCellStyleLayerKey = this._options.copiedCellStyleLayerKey || 'copy-manager';
    this._copiedCellStyle = this._options.copiedCellStyle || 'copied';
    this._onCopyInit = this._options.onCopyInit || undefined;
    this._onCopySuccess = this._options.onCopySuccess || undefined;
  }

  init(grid: SlickGrid) {
    this._grid = grid;
    Utils.addSlickEventPubSubWhenDefined(grid.getPubSubService(), this);
    this._eventHandler.subscribe(this._grid.onKeyDown, this.handleKeyDown.bind(this));

    // we need a cell selection model
    const cellSelectionModel = grid.getSelectionModel();
    if (!cellSelectionModel) {
      throw new Error('Selection model is mandatory for this plugin. Please set a selection model on the grid before adding this plugin: grid.setSelectionModel(new Slick.CellSelectionModel())');
    }
    // we give focus on the grid when a selection is done on it.
    // without this, if the user selects a range of cell without giving focus on a particular cell, the grid doesn't get the focus and key stroke handles (ctrl+c) don't work
    this._eventHandler.subscribe(cellSelectionModel.onSelectedRangesChanged, () => {
      if (!this._grid.getEditorLock().isActive()) {
        this._grid.focus();
      }
    });
  }

  destroy() {
    this._eventHandler.unsubscribeAll();
  }

  protected getHeaderValueForColumn(columnDef: Column): string {
    if (this._options.headerColumnValueExtractor) {
      const val = Utils.getHtmlStringOutput(this._options.headerColumnValueExtractor(columnDef));
      if (val) {
        return val;
      }
    }

    return Utils.getHtmlStringOutput(columnDef.name || '');
  }

  protected getDataItemValueForColumn(item: any, columnDef: Column, event: SlickEventData): string {
    if (typeof this._options.dataItemColumnValueExtractor === 'function') {
      const val = this._options.dataItemColumnValueExtractor(item, columnDef) as string | null;
      if (val) {
        return val;
      }
    }

    let retVal = '';

    // if a custom getter is not defined, we call serializeValue of the editor to serialize
    if (columnDef?.editor) {
      const tmpP = document.createElement('p');
      const editor = new (columnDef.editor as any)({
        container: tmpP,  // a dummy container
        column: columnDef,
        event,
        position: { top: 0, left: 0 },  // a dummy position required by some editors
        grid: this._grid,
      });
      editor.loadValue(item);
      retVal = editor.serializeValue();
      editor.destroy();
      tmpP.remove();
    } else {
      retVal = item[columnDef.field || ''];
    }

    return retVal;
  }

  protected setDataItemValueForColumn(item: any, columnDef: Column, value: string): null | string | void {
    if (columnDef.denyPaste) {
      return null;
    }

    if (this._options.dataItemColumnValueSetter) {
      return this._options.dataItemColumnValueSetter(item, columnDef, value) as string;
    }

    // if a custom setter is not defined, we call applyValue of the editor to unserialize
    if (columnDef.editor) {
      const tmpDiv = document.createElement('div');
      const editor = new (columnDef.editor as any)({
        container: tmpDiv, // a dummy container
        column: columnDef,
        position: { top: 0, left: 0 },  // a dummy position required by some editors
        grid: this._grid
      });
      editor.loadValue(item);
      editor.applyValue(item, value);
      editor.destroy();
      tmpDiv.remove();
    } else {
      item[columnDef.field] = value;
    }
  }


  protected _decodeTabularData(grid: SlickGrid, clipText: string) {
    const columns = grid.getColumns();
    const clipRows = clipText.split(/\r\n|[\n\f\r]/);
    // trim trailing CR if present
    if (clipRows[clipRows.length - 1] === '') {
      clipRows.pop();
    }

    let j = 0;
    const clippedRange: any[] = [];

    for (let i = 0; i < clipRows.length; i++) {
      if (clipRows[i] !== '') {
        clippedRange[j++] = clipRows[i].split('\t');
      } else {
        clippedRange[j++] = [''];
      }
    }
    const selectedCell = grid.getActiveCell();
    const ranges = grid.getSelectionModel()?.getSelectedRanges();
    const selectedRange = ranges && ranges.length ? ranges[0] : null;   // pick only one selection
    let activeRow: number;
    let activeCell: number;

    if (selectedRange) {
      activeRow = selectedRange.fromRow;
      activeCell = selectedRange.fromCell;
    } else if (selectedCell) {
      activeRow = selectedCell.row;
      activeCell = selectedCell.cell;
    } else {
      // we don't know where to paste
      return;
    }

    let oneCellToMultiple = false;
    let destH = clippedRange.length;
    let destW = clippedRange.length ? clippedRange[0].length : 0;
    if (clippedRange.length === 1 && clippedRange[0].length === 1 && selectedRange) {
      oneCellToMultiple = true;
      destH = selectedRange.toRow - selectedRange.fromRow + 1;
      destW = selectedRange.toCell - selectedRange.fromCell + 1;
    }
    const availableRows = (grid.getData() as any[]).length - (activeRow || 0);
    let addRows = 0;

    // ignore new rows if we don't have a "newRowCreator"
    if (availableRows < destH && typeof this._options.newRowCreator === 'function') {
      const d = grid.getData<any[]>();
      for (addRows = 1; addRows <= destH - availableRows; addRows++) {
        d.push({});
      }
      grid.setData(d);
      grid.render();
    }

    const overflowsBottomOfGrid = (activeRow || 0) + destH > grid.getDataLength();
    if (this._options.newRowCreator && overflowsBottomOfGrid) {
      const newRowsNeeded = (activeRow || 0) + destH - grid.getDataLength();
      this._options.newRowCreator(newRowsNeeded);
    }

    let lastDestX = activeCell;
    const clipCommand: ExternalCopyClipCommand = {
      isClipboardCommand: true,
      clippedRange,
      oldValues: [],
      cellExternalCopyManager: this,
      _options: this._options,
      setDataItemValueForColumn: this.setDataItemValueForColumn.bind(this),
      markCopySelection: this.markCopySelection.bind(this),
      oneCellToMultiple,
      activeRow,
      activeCell,
      destH,
      destW,
      maxDestY: grid.getDataLength(),
      maxDestX: grid.getColumns().length,
      h: 0,
      w: 0,
      execute: () => {
        clipCommand.h = 0;
        lastDestX = activeCell;
        for (let y = 0; y < clipCommand.destH; y++) {
          clipCommand.oldValues[y] = [];
          clipCommand.w = 0;
          clipCommand.h++;
          let xOffset = 0; // the x offset for hidden col

          for (let x = 0; x < clipCommand.destW; x++) {
            const desty = activeRow + y;
            const destx = activeCell + x;
            const column = columns[destx];

            if (!column) {
              break;
            }

            // paste on hidden column will be skipped, but we need to paste 1 cell further on X axis
            // we'll increase our X and increase the offset`
            if (column.hidden) {
              clipCommand.destW++;
              xOffset++;
              continue;
            }
            clipCommand.w++;
            lastDestX = destx;

            if (desty < clipCommand.maxDestY && destx < clipCommand.maxDestX) {
              const dt = grid.getDataItem(desty);

              clipCommand.oldValues[y][x - xOffset] = dt[column['field']];
              if (oneCellToMultiple) {
                clipCommand.setDataItemValueForColumn(dt, column, clippedRange[0][0]);
              } else {
                clipCommand.setDataItemValueForColumn(dt, column, clippedRange[y] ? clippedRange[y][x - xOffset] : '');
              }
              grid.updateCell(desty, destx);
              grid.onCellChange.notify({
                row: desty,
                cell: destx,
                item: dt,
                grid,
                column: {} as Column
              });
            }
          }
        }

        const bRange = new SlickRange(activeRow, activeCell, activeRow + clipCommand.h - 1, lastDestX);

        this.markCopySelection([bRange]);
        grid.getSelectionModel()?.setSelectedRanges([bRange]);
        this.onPasteCells.notify({ ranges: [bRange] });
      },
      undo: () => {
        for (let y = 0; y < clipCommand.destH; y++) {
          let xOffset = 0;
          for (let x = 0; x < clipCommand.destW; x++) {
            const desty = activeRow + y;
            const destx = activeCell + x;
            const column = columns[destx];

            if (!column) {
              break;
            }

            if (column.hidden) {
              xOffset++;
              continue;
            }

            if (desty < clipCommand.maxDestY && destx < clipCommand.maxDestX) {
              const dt = grid.getDataItem(desty);
              // Always restore from the stored old value for each cell, regardless of oneCellToMultiple
              clipCommand.setDataItemValueForColumn(dt, column, clipCommand.oldValues[y][x - xOffset]);
              grid.updateCell(desty, destx);
              grid.onCellChange.notify({
                row: desty,
                cell: destx,
                item: dt,
                grid,
                column: {} as Column
              });
            }
          }
        }

        const bRange = new SlickRange(activeRow, activeCell, activeRow + clipCommand.h - 1, lastDestX);

        this.markCopySelection([bRange]);
        grid.getSelectionModel()?.setSelectedRanges([bRange]);
        if (typeof this._options.onPasteCells === 'function') {
          this.onPasteCells.notify({ ranges: [bRange] });
        }

        if (addRows > 1) {
          const d = grid.getData<any[]>();
          for (; addRows > 1; addRows--) {
            d.splice(d.length - 1, 1);
          }
          grid.setData(d);
          grid.render();
        }
      }
    };

    if (typeof this._options.clipboardCommandHandler === 'function') {
      this._options.clipboardCommandHandler(clipCommand);
    } else {
      clipCommand.execute();
    }
  }

  protected async handleKeyDown(e: SlickEventData): Promise<boolean | void> {
    try {
      let ranges: SlickRange_[];
      if (!this._grid.getEditorLock().isActive() || this._grid.getOptions().autoEdit) {
        if (e.key === 'Escape') {
          if (this._copiedRanges) {
            e.preventDefault();
            this.clearCopySelection();
            this.onCopyCancelled.notify({ ranges: this._copiedRanges });
            this._copiedRanges = null;
          }
        }

        if ((e.key?.toLowerCase() === 'c' || e.key === 'Insert') && (e.ctrlKey || e.metaKey) && !e.shiftKey) {    // CTRL+C or CTRL+INS
          if (typeof this._onCopyInit === 'function') {
            this._onCopyInit.call(this);
          }
          ranges = this._grid.getSelectionModel()?.getSelectedRanges() ?? [];
          if (ranges.length !== 0) {
            e.preventDefault();
            this._copiedRanges = ranges;
            this.markCopySelection(ranges);
            this.onCopyCells.notify({ ranges });

            const columns = this._grid.getColumns();
            const fromRow = Math.min(...ranges.map((range) => range.fromRow));
            const fromCell = Math.min(...ranges.map((range) => range.fromCell));
            const toRow = Math.max(...ranges.map((range) => range.toRow));
            const toCell = Math.max(...ranges.map((range) => range.toCell));
            let clipText = '';

            const clipTextRows: string[] = [];
            if (this._options.includeHeaderWhenCopying) {
              const clipTextHeaders: string[] = [];
              for (let j = fromCell; j <= toCell; j++) {
                const column = columns[j];
                const isSelectedColumn = ranges.some((range) => j >= range.fromCell && j <= range.toCell);
                if (column) {
                  const colName: string = column.name instanceof HTMLElement
                    ? (column.name as HTMLElement).innerHTML
                    : column.name as string;
                  if (colName.length > 0 && !column.hidden) {
                    clipTextHeaders.push(isSelectedColumn ? this.getHeaderValueForColumn(column) || '' : '');
                  }
                }
              }
              clipTextRows.push(clipTextHeaders.join('\t'));
            }

            for (let i = fromRow; i <= toRow; i++) {
              const clipTextCells: string[] = [];
              const dt = this._grid.getDataItem(i);
              for (let j = fromCell; j <= toCell; j++) {
                const column = columns[j];
                if (column) {
                  const colName: string = column.name instanceof HTMLElement
                    ? (column.name as HTMLElement).innerHTML
                    : column.name as string;
                  if (colName.length > 0 && !column.hidden) {
                    clipTextCells.push(
                      ranges.some((range) => range.contains(i, j)) ? this.getDataItemValueForColumn(dt, column, e) : ''
                    );
                  }
                }
              }
              clipTextRows.push(clipTextCells.join('\t'));
            }
            clipText += clipTextRows.join('\r\n') + '\r\n';

            const clipboardWriteFn = this._options.clipboardWriteOverride;
            if (clipboardWriteFn) {
              await clipboardWriteFn(clipText);
            } else {
              await navigator.clipboard.writeText(clipText);
            }

            if (typeof this._onCopySuccess === 'function') {
              // If it's cell selection, use the toRow/fromRow fields
              const rowCount = ranges.length === 1 ? (ranges[0].toRow + 1) - ranges[0].fromRow : ranges.length;
              this._onCopySuccess(rowCount);
            }

            return false;
          }
        }

        if (!this._options.readOnlyMode && (
          (e.key?.toLowerCase() === 'v' && (e.ctrlKey || e.metaKey) && !e.shiftKey)
          || (e.key === 'Insert' && e.shiftKey && !e.ctrlKey)
        )) {    // CTRL+V or Shift+INS
          e.preventDefault();
          const clipboardReadFn = this._options.clipboardReadOverride;
          const clipText = clipboardReadFn ? await clipboardReadFn() : await navigator.clipboard.readText();
          this._decodeTabularData(this._grid, clipText);
          return false;
        }
      }
    } catch (err) {
      console.error(`Unable to read/write to clipboard. Please check your browser settings or permissions. Error: ${err}`);
    }
  }

  protected markCopySelection(ranges: SlickRange_[]) {
    this.clearCopySelection();

    const columns = this._grid.getColumns();
    const hash: CssStyleHash = Object.create(null);
    for (let i = 0; i < ranges.length; i++) {
      for (let j = ranges[i].fromRow; j <= ranges[i].toRow; j++) {
        hash[j] = Object.create(null);
        for (let k = ranges[i].fromCell; k <= ranges[i].toCell && k < columns.length; k++) {
          hash[j][columns[k].id] = this._copiedCellStyle;
        }
      }
    }
    this._grid.setCellCssStyles(this._copiedCellStyleLayerKey, hash);
    window.clearTimeout(this._clearCopyTI);
    this._clearCopyTI = window.setTimeout(() => {
      this.clearCopySelection();
    }, this._options?.clearCopySelectionDelay || CLEAR_COPY_SELECTION_DELAY);
  }

  clearCopySelection() {
    this._grid.removeCellCssStyles(this._copiedCellStyleLayerKey);
  }

  setIncludeHeaderWhenCopying(includeHeaderWhenCopying: boolean) {
    this._options.includeHeaderWhenCopying = includeHeaderWhenCopying;
  }
}

// extend Slick namespace on window object when building as iife
/* v8 ignore next -- IIFE_ONLY is compiled as false in the unit-test build. */
if (IIFE_ONLY && window.Slick) {
  Utils.extend(true, window, {
    Slick: {
      CellExternalCopyManager: SlickCellExternalCopyManager
    }
  });
}