"use client";

import { useEffect, useState } from "react";

export interface AgentStatus {
  agentName: string;
  status: "pending" | "running" | "completed" | "failed";
  durationMs?: number;
  outputSummary?: string;
  error?: string;
}

const AGENT_NAMES = [
  "trend-scout",
  "marketing-research-agent",
  "script-writer",
  "ad-creative-designer",
  "video-ad-producer",
  "copywriter-agent",
  "distribution-agent",
];

export function usePipelineProgress(campaignId: string | null) {
  const [agents, setAgents] = useState<AgentStatus[]>(
    AGENT_NAMES.map((name) => ({ agentName: name, status: "pending" }))
  );
  const [pipelineStatus, setPipelineStatus] = useState<string>("idle");

  useEffect(() => {
    if (!campaignId) return;

    const source = new EventSource(`/api/campaigns/${campaignId}/stream`);

    source.onmessage = (event) => {
      try {
        const data = JSON.parse(event.data);

        if (data.type === "pipeline_started") {
          setPipelineStatus("running");
        } else if (data.type === "agent_started") {
          setAgents((prev) =>
            prev.map((a) =>
              a.agentName === data.agentName
                ? { ...a, status: "running" }
                : a
            )
          );
        } else if (data.type === "agent_completed") {
          setAgents((prev) =>
            prev.map((a) =>
              a.agentName === data.agentName
                ? {
                    ...a,
                    status: "completed",
                    durationMs: data.durationMs,
                    outputSummary: data.outputSummary,
                  }
                : a
            )
          );
        } else if (data.type === "agent_failed") {
          setAgents((prev) =>
            prev.map((a) =>
              a.agentName === data.agentName
                ? { ...a, status: "failed", error: data.error }
                : a
            )
          );
        } else if (data.type === "pipeline_complete") {
          setPipelineStatus(data.status || "complete");
        }
      } catch {
        // ignore parse errors
      }
    };

    source.onerror = () => {
      source.close();
    };

    return () => source.close();
  }, [campaignId]);

  return { agents, pipelineStatus };
}