import "server-only";

import { upsertSystemSetting } from "@/lib/db/queries";
import {
  AGENT_PSD_TEMPLATES_KEY,
  type AgentPsdTemplate,
} from "@/lib/agents/psd-template-config";
import { readAgentPsdTemplates } from "@/lib/agents/psd-template-settings";

const DEFAULT_PARSE_HEARTBEAT_INTERVAL_MS = 25_000;

function clampProgress(value: number) {
  return Math.max(0, Math.min(99, Math.round(Number(value || 0))));
}

export async function updateAgentPsdTemplateById(params: {
  templateId: string;
  updatedBy: string;
  updater: (template: AgentPsdTemplate) => AgentPsdTemplate;
}) {
  const templates = await readAgentPsdTemplates();
  const currentTemplate = templates.find((entry) => entry.id === params.templateId);

  if (!currentTemplate) {
    return null;
  }

  const nextTemplate = params.updater(currentTemplate);
  await upsertSystemSetting({
    key: AGENT_PSD_TEMPLATES_KEY,
    value: templates.map((entry) =>
      entry.id === params.templateId ? nextTemplate : entry
    ),
    updatedBy: params.updatedBy,
  });

  return nextTemplate;
}

export async function updateAgentPsdTemplateParseProgress(params: {
  templateId: string;
  updatedBy: string;
  progress: number;
  stage: string;
  error?: string;
  restart?: boolean;
}) {
  const now = new Date().toISOString();

  return updateAgentPsdTemplateById({
    templateId: params.templateId,
    updatedBy: params.updatedBy,
    updater: (template) => {
      if (!params.restart && template.parseStatus !== "processing") {
        return template;
      }

      return {
        ...template,
        parseStatus: "processing",
        parseProgress: clampProgress(params.progress),
        parseStage: params.stage,
        parseError: params.error,
        parseStartedAt:
          params.restart || !template.parseStartedAt
            ? now
            : template.parseStartedAt,
        parseHeartbeatAt: now,
        updatedAt: now,
      };
    },
  });
}

export function createAgentPsdTemplateParseHeartbeat(params: {
  templateId: string;
  updatedBy: string;
  getSnapshot: () => {
    progress: number;
    stage: string;
    error?: string;
  };
  intervalMs?: number;
}) {
  let stopped = false;
  let inFlight = false;
  let failedBeats = 0;

  const interval = setInterval(() => {
    if (stopped || inFlight) {
      return;
    }

    inFlight = true;
    const snapshot = params.getSnapshot();
    void updateAgentPsdTemplateParseProgress({
      templateId: params.templateId,
      updatedBy: params.updatedBy,
      progress: snapshot.progress,
      stage: snapshot.stage,
      error: snapshot.error,
    })
      .then(() => {
        failedBeats = 0;
      })
      .catch((error) => {
        failedBeats += 1;
        if (failedBeats <= 3) {
          console.warn("[PSD Template] parse heartbeat update failed:", {
            templateId: params.templateId,
            failedBeats,
            error,
          });
        }
      })
      .finally(() => {
        inFlight = false;
      });
  }, params.intervalMs || DEFAULT_PARSE_HEARTBEAT_INTERVAL_MS);

  return {
    stop() {
      stopped = true;
      clearInterval(interval);
    },
  };
}