import { BaseIndicator } from './base.js';

export class ATRIndicator extends BaseIndicator {
    calculate(candles) {
        const period = this.params.period || 14;
        const results = new Array(candles.length).fill(null);
        const tr = new Array(candles.length).fill(0);
        
        for (let i = 1; i < candles.length; i++) {
            const h_l = candles[i].high - candles[i].low;
            const h_pc = Math.abs(candles[i].high - candles[i-1].close);
            const l_pc = Math.abs(candles[i].low - candles[i-1].close);
            tr[i] = Math.max(h_l, h_pc, l_pc);
        }
        
        let atr = 0;
        let sum = 0;
        for (let i = 1; i <= period; i++) sum += tr[i];
        atr = sum / period;
        results[period] = atr;
        
        for (let i = period + 1; i < candles.length; i++) {
            atr = (atr * (period - 1) + tr[i]) / period;
            results[i] = atr;
        }
        return results;
    }
    
    getMetadata() {
        return {
            name: 'ATR',
            description: 'Average True Range - measures market volatility',
            inputs: [{ name: 'period', label: 'Period', type: 'number', default: 14, min: 1, max: 100 }],
            plots: [{ id: 'value', color: '#795548', title: 'ATR' }],
            displayMode: 'pane'
        };
    }
}