import type { Modifier, EstimateItem } from '../types';

export interface ModifierModule {
    id: string;
    name: string;
    description: string;
    defaultLabel: string;
    defaultValue: number;
    defaultValueType: 'percent' | 'amount' | 'unit';
    defaultUnitLabel?: string;
    calculate: (modifier: Modifier, subScopeTotalWithMarkup: number, subScopeItems: EstimateItem[]) => number;
    calculateDisplay?: (modifier: Modifier, subScopeTotalWithMarkup: number, subScopeItems: EstimateItem[]) => number;
}

const TaxModule: ModifierModule = {
    id: 'tax',
    name: 'Tax',
    description: 'Calculates percentage tax on the sub-scope total.',
    defaultLabel: 'Sales Tax',
    defaultValue: 0,
    defaultValueType: 'percent',
    calculate: (m, base) => {
        if (m.valueType === 'percent') return base * (m.value / 100);
        return m.value;
    }
};

const ManHoursModule: ModifierModule = {
    id: 'man-hours',
    name: 'Man-Hours',
    description: 'Calculates labor hours by dividing the sub-scope subtotal by a production factor.',
    defaultLabel: 'Estimated Hours',
    defaultValue: 30,
    defaultValueType: 'unit',
    defaultUnitLabel: 'factor',
    calculate: () => 0,
    calculateDisplay: (m, base) => {
        const factor = m.value || 1;
        return base / factor;
    }
};

const SimpleAdjustmentModule: ModifierModule = {
    id: 'adjustment',
    name: 'Fixed adjustment',
    description: 'Adds or subtracts a fixed amount or percentage.',
    defaultLabel: 'Adjustment',
    defaultValue: 0,
    defaultValueType: 'amount',
    calculate: (m, base) => {
        if (m.valueType === 'percent') return base * (m.value / 100);
        return m.value;
    }
};

export const MODIFIER_MODULES: ModifierModule[] = [
    TaxModule,
    ManHoursModule,
    SimpleAdjustmentModule
];

export const ModifierRegistry = {
    getModule: (id: string) => MODIFIER_MODULES.find(m => m.id === id) || SimpleAdjustmentModule,
    
    calculate: (modifier: Modifier, baseTotal: number, items: EstimateItem[]) => {
        const module = ModifierRegistry.getModule(modifier.moduleId);
        return module.calculate(modifier, baseTotal, items);
    },

    calculateDisplay: (modifier: Modifier, baseTotal: number, items: EstimateItem[]) => {
        const module = ModifierRegistry.getModule(modifier.moduleId);
        if (module.calculateDisplay) return module.calculateDisplay(modifier, baseTotal, items);
        return module.calculate(modifier, baseTotal, items);
    }
};