import { isNumber, stripHTML } from './utils';
import CellManager from './cellmanager';

export default function filterRows(rows, filters) {
    let filteredRowIndices = [];

    if (Object.keys(filters).length === 0) {
        return rows.map(row => row.meta.rowIndex);
    }

    for (let colIndex in filters) {
        const keyword = filters[colIndex];

        const filteredRows = filteredRowIndices.length ?
            filteredRowIndices.map(i => rows[i]) :
            rows;

        const cells = filteredRows.map(row => row[colIndex]);

        let filter = guessFilter(keyword);
        let filterMethod = getFilterMethod(rows, filter);

        if (filterMethod) {
            filteredRowIndices = filterMethod(filter.text, cells);
        } else {
            filteredRowIndices = cells.map(cell => cell.rowIndex);
        }
    }

    return filteredRowIndices;
};

function getFilterMethod(rows, filter) {
    const getFormattedValue = cell => {
        let formatter = CellManager.getCustomCellFormatter(cell);
        if (formatter && cell.content) {
            cell.html = formatter(cell.content, rows[cell.rowIndex], cell.column, rows[cell.rowIndex]);
            return stripHTML(cell.html);
        }
        return cell.content || '';
    };

    const stringCompareValue = cell =>
        String(stripHTML(cell.html || '') || getFormattedValue(cell)).toLowerCase();

    const numberCompareValue = cell => parseFloat(cell.content);

    const getCompareValues = (cell, keyword) => {
        if (cell.column.compareValue) {
            const compareValues = cell.column.compareValue(cell, keyword);
            if (compareValues && Array.isArray(compareValues)) return compareValues;
        }

        // check if it can be converted to number
        const float = numberCompareValue(cell);
        if (!isNaN(float)) {
            return [float, keyword];
        }

        return [stringCompareValue(cell), keyword];
    };

    let filterMethodMap = {
        contains(keyword, cells) {
            return cells
                .filter(cell => {
                    const hay = stringCompareValue(cell);
                    const needle = (keyword || '').toLowerCase();
                    return !needle || hay.includes(needle);
                })
                .map(cell => cell.rowIndex);
        },

        greaterThan(keyword, cells) {
            return cells
                .filter(cell => {
                    const [compareValue, keywordValue] = getCompareValues(cell, keyword);
                    return compareValue > keywordValue;
                })
                .map(cell => cell.rowIndex);
        },

        lessThan(keyword, cells) {
            return cells
                .filter(cell => {
                    const [compareValue, keywordValue] = getCompareValues(cell, keyword);
                    return compareValue < keywordValue;
                })
                .map(cell => cell.rowIndex);
        },

        equals(keyword, cells) {
            return cells
                .filter(cell => {
                    const value = parseFloat(cell.content);
                    return value === keyword;
                })
                .map(cell => cell.rowIndex);
        },

        notEquals(keyword, cells) {
            return cells
                .filter(cell => {
                    const value = parseFloat(cell.content);
                    return value !== keyword;
                })
                .map(cell => cell.rowIndex);
        },

        range(rangeValues, cells) {
            return cells
                .filter(cell => {
                    const values1 = getCompareValues(cell, rangeValues[0]);
                    const values2 = getCompareValues(cell, rangeValues[1]);
                    const value = values1[0];
                    return value >= values1[1] && value <= values2[1];
                })
                .map(cell => cell.rowIndex);
        },

        containsNumber(keyword, cells) {
            return cells
                .filter(cell => {
                    let number = parseFloat(keyword, 10);
                    let string = keyword;
                    let hayNumber = numberCompareValue(cell);
                    let hayString = stringCompareValue(cell);

                    return number === hayNumber || hayString.includes(string);
                })
                .map(cell => cell.rowIndex);
        }
    };

    return filterMethodMap[filter.type];
}

function guessFilter(keyword = '') {
    if (keyword.length === 0) return {};

    let compareString = keyword;

    if (['>', '<', '='].includes(compareString[0])) {
        compareString = keyword.slice(1);
    } else if (compareString.startsWith('!=')) {
        compareString = keyword.slice(2);
    }

    if (keyword.startsWith('>')) {
        if (compareString) {
            return {
                type: 'greaterThan',
                text: compareString.trim()
            };
        }
    }

    if (keyword.startsWith('<')) {
        if (compareString) {
            return {
                type: 'lessThan',
                text: compareString.trim()
            };
        }
    }

    if (keyword.startsWith('=')) {
        if (isNumber(compareString)) {
            return {
                type: 'equals',
                text: Number(keyword.slice(1).trim())
            };
        }
    }

    if (isNumber(compareString)) {
        return {
            type: 'containsNumber',
            text: compareString
        };
    }

    if (keyword.startsWith('!=')) {
        if (isNumber(compareString)) {
            return {
                type: 'notEquals',
                text: Number(keyword.slice(2).trim())
            };
        }
    }

    if (keyword.split(':').length === 2) {
        compareString = keyword.split(':');
        return {
            type: 'range',
            text: compareString.map(v => v.trim())
        };
    }

    return {
        type: 'contains',
        text: compareString.toLowerCase()
    };
}