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

export class RSIIndicator extends BaseIndicator {
    calculate(candles) {
        const period = this.params.period || 14;
        const results = new Array(candles.length).fill(null);
        let gains = 0, losses = 0;
        for (let i = 1; i < candles.length; i++) {
            const diff = candles[i].close - candles[i-1].close;
            const gain = diff > 0 ? diff : 0;
            const loss = diff < 0 ? -diff : 0;
            if (i <= period) {
                gains += gain;
                losses += loss;
                if (i === period) {
                    let avgGain = gains / period;
                    let avgLoss = losses / period;
                    results[i] = 100 - (100 / (1 + (avgGain / (avgLoss || 0.00001))));
                }
            } else {
                const lastAvgGain = (results[i-1] ? (results[i-1] > 0 ? (period-1) * (results[i-1] * (gains+losses)/100) : 0) : 0);
                gains = (gains * (period - 1) + gain) / period;
                losses = (losses * (period - 1) + loss) / period;
                results[i] = 100 - (100 / (1 + (gains / (losses || 0.00001))));
            }
        }
        return results;
    }
    
    getMetadata() {
        return {
            name: 'RSI',
            inputs: [{ name: 'period', label: 'Period', type: 'number', default: 14, min: 1, max: 100 }],
            plots: [{ id: 'value', color: '#9c27b0', title: 'RSI' }]
        };
    }
}