import { Injectable, Logger } from '@nestjs/common';
import { PlatformGraphqlService } from '../../platform/platform-graphql.service';
import type { ActionHandler, ActionResult } from '../types/action.types';
import type { RuleAction, EscalateActionParams } from '../types/rule.types';

/**
 * Persists a PerformanceAlert when a rule's escalate action fires.
 *
 * Dedupes by (agentId, alertType, IST date) — a single rule firing every
 * 5 min should only produce ONE alert per day per agent until dismissed.
 * If a row already exists for that key today and is not dismissed, the
 * action is a no-op (returns the existing id). If the existing row was
 * dismissed earlier today, we don't re-fire — supervisor explicitly
 * acknowledged.
 */
@Injectable()
export class EscalateActionHandler implements ActionHandler {
    type = 'escalate';
    private readonly logger = new Logger(EscalateActionHandler.name);

    constructor(private readonly platform: PlatformGraphqlService) {}

    async execute(action: RuleAction, context: Record<string, any>): Promise<ActionResult> {
        const params = action.params as EscalateActionParams & { ruleId?: string; alertType?: string };
        const agentId = context['agent.id'] as string | undefined;
        const agentName = (context['agent.name'] as string | undefined) ?? '';
        const valueRaw = context['_alertValue'];
        const valueText = valueRaw != null ? String(valueRaw) : null;

        if (!agentId) {
            return { success: false, error: 'agent.id missing from facts' };
        }

        const alertType = params.alertType ?? this.inferAlertType(params.message);
        const severity = (params.severity ?? 'warning').toUpperCase(); // INFO | WARNING | CRITICAL
        const today = this.todayIst();

        // Dedupe: any non-dismissed alert today for this agent + type?
        try {
            const existing = await this.platform.query<any>(
                `{ performanceAlerts(first: 1, filter: {
                    agentId: { eq: "${agentId}" },
                    alertType: { eq: ${alertType} },
                    firedAt: { gte: "${today}T00:00:00+05:30", lte: "${today}T23:59:59+05:30" }
                }) { edges { node { id dismissedAt value } } } }`,
            );
            const existingNode = existing?.performanceAlerts?.edges?.[0]?.node;
            if (existingNode) {
                // Already fired today. If value changed, update it; otherwise no-op.
                if (!existingNode.dismissedAt && existingNode.value !== valueText) {
                    await this.platform.query<any>(
                        `mutation($id: UUID!, $data: PerformanceAlertUpdateInput!) { updatePerformanceAlert(id: $id, data: $data) { id } }`,
                        { id: existingNode.id, data: { value: valueText } },
                    );
                }
                return { success: true, data: { id: existingNode.id, deduped: true, agentId, alertType } };
            }

            const created = await this.platform.query<any>(
                `mutation($data: PerformanceAlertCreateInput!) { createPerformanceAlert(data: $data) { id } }`,
                {
                    data: {
                        name: `${agentName || agentId}: ${params.message ?? alertType}${valueText ? ` (${valueText})` : ''}`,
                        agentId,
                        alertType,
                        severity,
                        message: params.message ?? alertType,
                        value: valueText,
                        ruleId: params.ruleId ?? null,
                        firedAt: new Date().toISOString(),
                    },
                },
            );
            const id = created?.createPerformanceAlert?.id;
            this.logger.log(`[ESCALATE] Created alert ${id} agent=${agentName ?? agentId} type=${alertType} value=${valueText}`);
            return { success: true, data: { id, agentId, alertType, severity, message: params.message } };
        } catch (err: any) {
            this.logger.warn(`[ESCALATE] Failed for agent=${agentId}: ${err?.message ?? err}`);
            return { success: false, error: String(err?.message ?? err) };
        }
    }

    private inferAlertType(message: string | undefined): string {
        const m = (message ?? '').toLowerCase();
        if (m.includes('idle')) return 'EXCESSIVE_IDLE';
        if (m.includes('nps')) return 'LOW_NPS';
        if (m.includes('conversion')) return 'LOW_CONVERSION';
        return 'OTHER';
    }

    private todayIst(): string {
        const ist = new Date(Date.now() + 5.5 * 60 * 60 * 1000);
        return ist.toISOString().slice(0, 10);
    }
}