import { Injectable } from '@angular/core';
import { Subject } from 'rxjs';
import { cloneArray, reverseMapper, mergeObjects } from '../core/utils';
import { DataUtil, GridColumnDataType } from '../data-operations/data-util';
import { IFilteringExpressionsTree } from '../data-operations/filtering-expressions-tree';
import { Transaction, TransactionType, State } from '../services/transaction/transaction';
import { IgxCell, IgxGridCRUDService, IgxEditRow } from './common/crud.service';
import { CellType, ColumnType, GridServiceType, GridType, RowType } from './common/grid.interface';
import { IGridEditEventArgs, IPinRowEventArgs, IRowToggleEventArgs } from './common/events';
import { IgxColumnMovingService } from './moving/moving.service';
import { IGroupingExpression } from '../data-operations/grouping-expression.interface';
import { ISortingExpression, SortingDirection } from '../data-operations/sorting-strategy';
import { FilterUtil } from '../data-operations/filtering-strategy';

/**
 * @hidden
 */
@Injectable()
export class GridBaseAPIService<T extends GridType> implements GridServiceType {


    public grid: T;
    protected destroyMap: Map<string, Subject<boolean>> = new Map<string, Subject<boolean>>();

    constructor(
        public crudService: IgxGridCRUDService,
        public cms: IgxColumnMovingService
    ) { }

    public get_column_by_name(name: string): ColumnType {
        return this.grid.columns.find((col: ColumnType) => col.field === name);
    }

    public get_summary_data() {
        const grid = this.grid;
        let data = grid.filteredData;
        if (data && grid.hasPinnedRecords) {
            data = grid._filteredUnpinnedData;
        }
        if (!data) {
            if (grid.transactions.enabled) {
                data = DataUtil.mergeTransactions(
                    cloneArray(grid.data),
                    grid.transactions.getAggregatedChanges(true),
                    grid.primaryKey,
                    grid.dataCloneStrategy
                );
                const deletedRows = grid.transactions.getTransactionLog().filter(t => t.type === TransactionType.DELETE).map(t => t.id);
                deletedRows.forEach(rowID => {
                    const tempData = grid.primaryKey ? data.map(rec => rec[grid.primaryKey]) : data;
                    const index = tempData.indexOf(rowID);
                    if (index !== -1) {
                        data.splice(index, 1);
                    }
                });
            } else {
                data = grid.data;
            }
        }
        return data;
    }

    /**
     * @hidden
     * @internal
     */
    public getRowData(rowID: any) {
        const data = this.get_all_data(this.grid.transactions.enabled);
        const index = this.get_row_index_in_data(rowID, data);
        return data[index];
    }

    public get_row_index_in_data(rowID: any, dataCollection?: any[]): number {
        const grid = this.grid;
        if (!grid) {
            return -1;
        }
        const data = dataCollection ?? this.get_all_data(grid.transactions.enabled);
        return grid.primaryKey ? data.findIndex(record => record.recordRef ? record.recordRef[grid.primaryKey] === rowID
            : record[grid.primaryKey] === rowID) : data.indexOf(rowID);
    }

    public get_row_by_key(rowSelector: any): RowType {
        if (!this.grid) {
            return null;
        }
        const primaryKey = this.grid.primaryKey;
        if (primaryKey !== undefined && primaryKey !== null) {
            return this.grid.dataRowList.find((row) => row.data[primaryKey] === rowSelector);
        } else {
            return this.grid.dataRowList.find((row) => row.data === rowSelector);
        }
    }

    public get_row_by_index(rowIndex: number): RowType {
        return this.grid.rowList.find((row) => row.index === rowIndex);
    }

    /**
     * Gets the rowID of the record at the specified data view index
     *
     * @param index
     * @param dataCollection
     */
    public get_rec_id_by_index(index: number, dataCollection?: any[]): any {
        dataCollection = dataCollection || this.grid.data;
        if (index >= 0 && index < dataCollection.length) {
            const rec = dataCollection[index];
            return this.grid.primaryKey ? rec[this.grid.primaryKey] : rec;
        }
        return null;
    }

    public get_cell_by_key(rowSelector: any, field: string): CellType {
        const row = this.get_row_by_key(rowSelector);
        if (row && row.cells) {
            return row.cells.find((cell) => cell.column.field === field);
        }
    }

    public get_cell_by_index(rowIndex: number, columnID: number | string): CellType {
        const row = this.get_row_by_index(rowIndex);
        const hasCells = row && row.cells;
        if (hasCells && typeof columnID === 'number') {
            return row.cells.find((cell) => cell.column.index === columnID);
        }
        if (hasCells && typeof columnID === 'string') {
            return row.cells.find((cell) => cell.column.field === columnID);
        }

    }

    public get_cell_by_visible_index(rowIndex: number, columnIndex: number): CellType {
        const row = this.get_row_by_index(rowIndex);
        if (row && row.cells) {
            return row.cells.find((cell) => cell.visibleColumnIndex === columnIndex);
        }
    }

    public update_cell(cell: IgxCell): IGridEditEventArgs {
        if (!cell) {
            return;
        }
        const args = cell.createEditEventArgs(true);

        this.grid.summaryService.clearSummaryCache(args);
        const data = this.getRowData(cell.id.rowID);
        const newRowData = reverseMapper(cell.column.field, args.newValue);
        this.updateData(this.grid, cell.id.rowID, data, cell.rowData, newRowData);
        if (!this.grid.crudService.row) {
            this.grid.validation.update(cell.id.rowID, newRowData);
        }
        if (this.grid.primaryKey === cell.column.field) {
            if (this.grid.pinnedRecords.length > 0) {
                const rowIndex = this.grid.pinnedRecords.indexOf(cell.rowData);
                if (rowIndex !== -1) {
                    const previousRowId = cell.value;
                    const rowType = this.grid.getRowByIndex(cell.rowIndex);
                    this.unpin_row(previousRowId, rowType);
                    this.pin_row(args.newValue, rowIndex, rowType);
                }
            }
            if (this.grid.selectionService.isRowSelected(cell.id.rowID)) {
                this.grid.selectionService.deselectRow(cell.id.rowID);
                this.grid.selectionService.selectRowById(args.newValue);
            }
            if (this.grid.hasSummarizedColumns) {
                this.grid.summaryService.removeSummaries(cell.id.rowID);
            }
        }
        if (!this.grid.rowEditable || !this.crudService.row ||
            this.crudService.row.id !== cell.id.rowID || !this.grid.transactions.enabled) {
            this.grid.summaryService.clearSummaryCache(args);
            this.grid.pipeTrigger++;
        }

        return args;
    }

    // TODO: CRUD refactor to not emit editing evts.
    public update_row(row: IgxEditRow, value: any, event?: Event) {
        const grid = this.grid;
        const selected = grid.selectionService.isRowSelected(row.id);
        const rowInEditMode = this.crudService.row;
        const data = this.get_all_data(grid.transactions.enabled);
        const index = this.get_row_index_in_data(row.id, data);
        const hasSummarized = grid.hasSummarizedColumns;
        this.crudService.updateRowEditData(row, value);

        const args = row.createEditEventArgs(true, event);

        // If no valid row is found
        if (index === -1) {
            return args;
        }

        if (rowInEditMode) {
            const hasChanges = grid.transactions.getState(args.rowID, true);
            grid.transactions.endPending(false);
            if (!hasChanges) {
                return args;
            }
        }

        if (!args.newValue) {
            return args;
        }

        if (hasSummarized) {
            grid.summaryService.removeSummaries(args.rowID);
        }

        this.updateData(grid, row.id, data[index], args.oldValue, args.newValue);
        this.grid.validation.update(row.id, args.newValue);
        const newId = grid.primaryKey ? args.newValue[grid.primaryKey] : args.newValue;
        if (selected) {
            grid.selectionService.deselectRow(row.id);
            grid.selectionService.selectRowById(newId);
        }
        // make sure selection is handled prior to updating the row.id
        row.id = newId;
        if (hasSummarized) {
            grid.summaryService.removeSummaries(newId);
        }
        grid.pipeTrigger++;

        return args;
    }

    public sort(expression: ISortingExpression): void {
        if (expression.dir === SortingDirection.None) {
            this.remove_grouping_expression(expression.fieldName);
        }
        const sortingState = cloneArray(this.grid.sortingExpressions);
        this.prepare_sorting_expression([sortingState], expression);
        this.grid.sortingExpressions = sortingState;
    }

    public sort_decoupled(expression: IGroupingExpression): void {
        if (expression.dir === SortingDirection.None) {
            this.remove_grouping_expression(expression.fieldName);
        }
        const groupingState = cloneArray((this.grid as any).groupingExpressions);
        this.prepare_grouping_expression([groupingState], expression);
        (this.grid as any).groupingExpressions = groupingState;
    }

    public sort_multiple(expressions: ISortingExpression[]): void {
        const sortingState = cloneArray(this.grid.sortingExpressions);

        for (const each of expressions) {
            if (each.dir === SortingDirection.None) {
                this.remove_grouping_expression(each.fieldName);
            }
            this.prepare_sorting_expression([sortingState], each);
        }

        this.grid.sortingExpressions = sortingState;
    }

    public sort_groupBy_multiple(expressions: ISortingExpression[]): void {
        const groupingState = cloneArray((this.grid as any).groupingExpressions);

        for (const each of expressions) {
            if (each.dir === SortingDirection.None) {
                this.remove_grouping_expression(each.fieldName);
            }
            this.prepare_grouping_expression([groupingState], each);
        }
    }

    public clear_sort(fieldName: string) {
        const sortingState = this.grid.sortingExpressions;
        const index = sortingState.findIndex((expr) => expr.fieldName === fieldName);
        if (index > -1) {
            sortingState.splice(index, 1);
            this.grid.sortingExpressions = sortingState;
        }
    }

    public clear_groupby(_name?: string | Array<string>) {
    }

    public should_apply_number_style(column: ColumnType): boolean {
        return column.dataType === GridColumnDataType.Number;
    }

    public get_data(): any[] {
        const grid = this.grid;
        const data = grid.data ? grid.data : [];
        return data;
    }

    public get_all_data(includeTransactions = false): any[] {
        const grid = this.grid;
        let data = grid && grid.data ? grid.data : [];
        data = includeTransactions ? grid.dataWithAddedInTransactionRows : data;
        return data;
    }

    public get_filtered_data(): any[] {
        return this.grid.filteredData;
    }

    public addRowToData(rowData: any, _parentID?: any) {
        // Add row goes to transactions and if rowEditable is properly implemented, added rows will go to pending transactions
        // If there is a row in edit - > commit and close
        const grid = this.grid;
        const rowId = grid.primaryKey ? rowData[grid.primaryKey] : rowData;
        if (grid.transactions.enabled) {
            const transaction: Transaction = { id: rowId, type: TransactionType.ADD, newValue: rowData };
            grid.transactions.add(transaction);
        } else {
            grid.data.push(rowData);
        }
        grid.validation.markAsTouched(rowId);
        grid.validation.update(rowId, rowData);
    }

    public deleteRowFromData(rowID: any, index: number) {
        //  if there is a row (index !== 0) delete it
        //  if there is a row in ADD or UPDATE state change it's state to DELETE
        const grid = this.grid;
        if (index !== -1) {
            if (grid.transactions.enabled) {
                const transaction: Transaction = { id: rowID, type: TransactionType.DELETE, newValue: null };
                grid.transactions.add(transaction, grid.data[index]);
            } else {
                grid.data.splice(index, 1);
            }
        } else {
            const state: State = grid.transactions.getState(rowID);
            grid.transactions.add({ id: rowID, type: TransactionType.DELETE, newValue: null }, state && state.recordRef);
        }
        grid.validation.clear(rowID);
    }

    public deleteRowById(rowId: any): any {
        let index: number;
        const grid = this.grid;
        const data = this.get_all_data();
        if (grid.primaryKey) {
            // eslint-disable-next-line @typescript-eslint/no-shadow
            index = data.map((record) => record[grid.primaryKey]).indexOf(rowId);
        } else {
            index = data.indexOf(rowId);
        }
        const state: State = grid.transactions.getState(rowId);
        const hasRowInNonDeletedState = state && state.type !== TransactionType.DELETE;

        //  if there is a row (index !== -1) and the we have cell in edit mode on same row exit edit mode
        //  if there is no row (index === -1), but there is a row in ADD or UPDATE state do as above
        //  Otherwise just exit - there is nothing to delete
        if (index !== -1 || hasRowInNonDeletedState) {
            // Always exit edit when row is deleted
            this.crudService.endEdit(true);
        } else {
            return;
        }

        const record = data[index];
        const key = record ? record[grid.primaryKey] : undefined;
        grid.rowDeletedNotifier.next({ data: record, owner: grid, primaryKey: key });

        this.deleteRowFromData(rowId, index);

        if (grid.selectionService.isRowSelected(rowId)) {
            grid.selectionService.deselectRowsWithNoEvent([rowId]);
        } else {
            grid.selectionService.clearHeaderCBState();
        }
        grid.pipeTrigger++;
        grid.notifyChanges();
        // Data needs to be recalculated if transactions are in place
        // If no transactions, `data` will be a reference to the grid getter, otherwise it will be stale
        const dataAfterDelete = grid.transactions.enabled ? grid.dataWithAddedInTransactionRows : data;
        grid.refreshSearch();
        if (dataAfterDelete.length % grid.perPage === 0 && dataAfterDelete.length / grid.perPage - 1 < grid.page && grid.page !== 0) {
            grid.page--;
        }

        return record;
    }

    public get_row_id(rowData) {
        return this.grid.primaryKey ? rowData[this.grid.primaryKey] : rowData;
    }

    public row_deleted_transaction(rowID: any): boolean {
        const grid = this.grid;
        if (!grid) {
            return false;
        }
        if (!grid.transactions.enabled) {
            return false;
        }
        const state = grid.transactions.getState(rowID);
        if (state) {
            return state.type === TransactionType.DELETE;
        }

        return false;
    }

    public get_row_expansion_state(record: any): boolean {
        const grid = this.grid;
        const states = grid.expansionStates;
        const rowID = grid.primaryKey ? record[grid.primaryKey] : record;
        const expanded = states.get(rowID);

        if (expanded !== undefined) {
            return expanded;
        } else {
            return grid.getDefaultExpandState(record);
        }
    }

    public set_row_expansion_state(rowID: any, expanded: boolean, event?: Event) {
        const grid = this.grid;
        const expandedStates = grid.expansionStates;

        if (!this.allow_expansion_state_change(rowID, expanded)) {
            return;
        }

        const args: IRowToggleEventArgs = {
            rowID,
            expanded,
            event,
            cancel: false
        };

        grid.rowToggle.emit(args);

        if (args.cancel) {
            return;
        }
        expandedStates.set(rowID, expanded);
        grid.expansionStates = expandedStates;
        // K.D. 28 Feb, 2022 #10634 Don't trigger endEdit/commit upon row expansion state change
        // this.crudService.endEdit(false);
    }

    public get_rec_by_id(rowID) {
        return this.grid.primaryKey ? this.getRowData(rowID) : rowID;
    }

    /**
     * Returns the index of the record in the data view by pk or -1 if not found or primaryKey is not set.
     *
     * @param pk
     * @param dataCollection
     */
    public get_rec_index_by_id(pk: string | number, dataCollection?: any[]): number {
        dataCollection = dataCollection || this.grid.data;
        return this.grid.primaryKey ? dataCollection.findIndex(rec => rec[this.grid.primaryKey] === pk) : -1;
    }

    public allow_expansion_state_change(rowID, expanded) {
        return this.grid.expansionStates.get(rowID) !== expanded;
    }

    public prepare_sorting_expression(stateCollections: Array<Array<any>>, expression: ISortingExpression) {
        if (expression.dir === SortingDirection.None) {
            stateCollections.forEach(state => {
                state.splice(state.findIndex((expr) => expr.fieldName === expression.fieldName), 1);
            });
            return;
        }

        /**
         * We need to make sure the states in each collection with same fields point to the same object reference.
         * If the different state collections provided have different sizes we need to get the largest one.
         * That way we can get the state reference from the largest one that has the same fieldName as the expression to prepare.
         */
        let maxCollection = stateCollections[0];
        for (let i = 1; i < stateCollections.length; i++) {
            if (maxCollection.length < stateCollections[i].length) {
                maxCollection = stateCollections[i];
            }
        }
        const maxExpr = maxCollection.find((expr) => expr.fieldName === expression.fieldName);

        stateCollections.forEach(collection => {
            const myExpr = collection.find((expr) => expr.fieldName === expression.fieldName);
            if (!myExpr && !maxExpr) {
                // Expression with this fieldName is missing from the current and the max collection.
                collection.push(expression);
            } else if (!myExpr && maxExpr) {
                // Expression with this fieldName is missing from the current and but the max collection has.
                collection.push(maxExpr);
                Object.assign(maxExpr, expression);
            } else {
                // The current collection has the expression so just update it.
                Object.assign(myExpr, expression);
            }
        });
    }

    public prepare_grouping_expression(stateCollections: Array<Array<any>>, expression: IGroupingExpression) {
        if (expression.dir === SortingDirection.None) {
            stateCollections.forEach(state => {
                state.splice(state.findIndex((expr) => expr.fieldName === expression.fieldName), 1);
            });
            return;
        }

        /**
         * We need to make sure the states in each collection with same fields point to the same object reference.
         * If the different state collections provided have different sizes we need to get the largest one.
         * That way we can get the state reference from the largest one that has the same fieldName as the expression to prepare.
         */
        let maxCollection = stateCollections[0];
        for (let i = 1; i < stateCollections.length; i++) {
            if (maxCollection.length < stateCollections[i].length) {
                maxCollection = stateCollections[i];
            }
        }
        const maxExpr = maxCollection.find((expr) => expr.fieldName === expression.fieldName);

        stateCollections.forEach(collection => {
            const myExpr = collection.find((expr) => expr.fieldName === expression.fieldName);
            if (!myExpr && !maxExpr) {
                // Expression with this fieldName is missing from the current and the max collection.
                collection.push(expression);
            } else if (!myExpr && maxExpr) {
                // Expression with this fieldName is missing from the current and but the max collection has.
                collection.push(maxExpr);
                Object.assign(maxExpr, expression);
            } else {
                // The current collection has the expression so just update it.
                Object.assign(myExpr, expression);
            }
        });
    }

    public remove_grouping_expression(_fieldName) {
    }

    public filterDataByExpressions(expressionsTree: IFilteringExpressionsTree): any[] {
        let data = this.get_all_data();

        if (expressionsTree.filteringOperands.length) {
            const state = { expressionsTree, strategy: this.grid.filterStrategy };
            data = FilterUtil.filter(cloneArray(data), state, this.grid);
        }

        return data;
    }

    public sortDataByExpressions(data: any[], expressions: ISortingExpression[]) {
        return DataUtil.sort(cloneArray(data), expressions, this.grid.sortStrategy, this.grid);
    }

    public pin_row(rowID: any, index?: number, row?: RowType): void {
        const grid = (this.grid as any);
        if (grid._pinnedRecordIDs.indexOf(rowID) !== -1) {
            return;
        }
        const eventArgs = this.get_pin_row_event_args(rowID, index, row, true);
        grid.rowPinning.emit(eventArgs);

        if (eventArgs.cancel) {
            return;
        }
        const insertIndex = typeof eventArgs.insertAtIndex === 'number' ? eventArgs.insertAtIndex : grid._pinnedRecordIDs.length;
        grid._pinnedRecordIDs.splice(insertIndex, 0, rowID);
    }

    public unpin_row(rowID: any, row: RowType): void {
        const grid = (this.grid as any);
        const index = grid._pinnedRecordIDs.indexOf(rowID);
        if (index === -1) {
            return;
        }
        const eventArgs = this.get_pin_row_event_args(rowID, null , row, false);
        grid.rowPinning.emit(eventArgs);

        if (eventArgs.cancel) {
            return;
        }
        grid._pinnedRecordIDs.splice(index, 1);
    }

    public get_pin_row_event_args(rowID: any, index?: number, row?: RowType, pinned?: boolean) {
        const eventArgs: IPinRowEventArgs = {
            isPinned: pinned ? true : false,
            rowID,
            row,
            cancel: false
        }
        if (typeof index === 'number') {
            eventArgs.insertAtIndex = index <= this.grid.pinnedRecords.length ? index : this.grid.pinnedRecords.length;
        }
        return eventArgs;
    }

    /**
     * Updates related row of provided grid's data source with provided new row value
     *
     * @param grid Grid to update data for
     * @param rowID ID of the row to update
     * @param rowValueInDataSource Initial value of the row as it is in data source
     * @param rowCurrentValue Current value of the row as it is with applied previous transactions
     * @param rowNewValue New value of the row
     */
    protected updateData(grid, rowID, rowValueInDataSource: any, rowCurrentValue: any, rowNewValue: { [x: string]: any }) {
        if (grid.transactions.enabled) {
            const transaction: Transaction = {
                id: rowID,
                type: TransactionType.UPDATE,
                newValue: rowNewValue
            };
            grid.transactions.add(transaction, rowCurrentValue);
        } else {
            mergeObjects(rowValueInDataSource, rowNewValue);
        }
    }


    protected update_row_in_array(value: any, rowID: any, index: number) {
        const grid = this.grid;
        grid.data[index] = value;
    }

    protected getSortStrategyPerColumn(fieldName: string) {
        return this.get_column_by_name(fieldName) ?
            this.get_column_by_name(fieldName).sortStrategy : undefined;
    }

}