"use client";

// ---------------------------------------------------------------------------
// Replay — re-run the intelligence pipeline over a past time range into a
// sandbox, then compare runs. Backend: drb-c2-core/app/internal/replay.py.
// Nothing here touches a live call or incident; every run spends real AI
// credits, so the form estimates first and only then offers Start.
// ---------------------------------------------------------------------------

import { useCallback, useEffect, useState } from "react";
import { c2api } from "@/lib/c2api";
import { useSystems } from "@/lib/useSystems";
import type {
  ReplayEstimate, ReplayIncident, ReplayIncidents, ReplayMode, ReplayRun, ReplayCallRow,
} from "@/lib/types";

const MODES: { key: ReplayMode; label: string; help: string }[] = [
  { key: "transcripts", label: "Saved transcripts", help: "Reuse each call's transcript; re-run extraction + correlation." },
  { key: "audio",       label: "Re-transcribe audio", help: "Whisper the saved audio again, then extract + correlate. For ranges where AI was off." },
  { key: "reuse",       label: "Correlation only",   help: "Reuse an earlier run's extraction; re-run correlation only. Isolates a correlator change." },
];

// Clears that came from the radio traffic itself, vs the 90-minute idle timer.
const SIGNAL_RESOLVES = ["units_cleared", "llm_closure", "reassignment", "children_resolved"];

const input =
  "bg-gray-800 border border-gray-700 rounded-lg px-3 py-1.5 text-white text-sm font-mono focus:outline-none focus:border-indigo-500";
const btn =
  "bg-gray-800 hover:bg-gray-700 disabled:opacity-50 border border-gray-700 text-white text-sm font-mono px-4 py-1.5 rounded-lg transition-colors";

function toLocalInput(d: Date): string {
  const pad = (n: number) => String(n).padStart(2, "0");
  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}T${pad(d.getHours())}:${pad(d.getMinutes())}`;
}

function fmtTime(iso: string | null | undefined): string {
  if (!iso) return "—";
  return new Date(iso).toLocaleString([], { month: "short", day: "numeric", hour: "2-digit", minute: "2-digit" });
}

function sum(rec: Record<string, number> | undefined, keys: string[]): number {
  return keys.reduce((n, k) => n + (rec?.[k] ?? 0), 0);
}

// ---------------------------------------------------------------------------

function NewRunForm({ runs, busy, onStarted }: { runs: ReplayRun[]; busy: boolean; onStarted: () => void }) {
  const { systems } = useSystems();
  const [from, setFrom] = useState(() => toLocalInput(new Date(Date.now() - 6 * 3600_000)));
  const [to, setTo] = useState(() => toLocalInput(new Date()));
  const [mode, setMode] = useState<ReplayMode>("transcripts");
  const [systemIds, setSystemIds] = useState<string[]>([]);
  const [sourceRun, setSourceRun] = useState("");
  const [label, setLabel] = useState("");
  const [est, setEst] = useState<ReplayEstimate | null>(null);
  const [working, setWorking] = useState(false);
  const [error, setError] = useState<string | null>(null);

  // Any change to what would be replayed invalidates the estimate.
  useEffect(() => { setEst(null); }, [from, to, mode, systemIds]);

  const sources = runs.filter((r) => r.status === "done" && r.mode !== "reuse");
  const range = () => ({ date_from: new Date(from).toISOString(), date_to: new Date(to).toISOString() });

  async function estimate() {
    setWorking(true); setError(null);
    try {
      setEst(await c2api.estimateReplay({ ...range(), mode, system_ids: systemIds }));
    } catch (e) { setError(String(e)); } finally { setWorking(false); }
  }

  async function start() {
    setWorking(true); setError(null);
    try {
      await c2api.startReplay({
        ...range(), mode, system_ids: systemIds, label,
        source_run_id: mode === "reuse" ? sourceRun : null,
      });
      setEst(null); setLabel("");
      onStarted();
    } catch (e) { setError(String(e)); } finally { setWorking(false); }
  }

  function toggleSystem(id: string) {
    setSystemIds((s) => (s.includes(id) ? s.filter((x) => x !== id) : [...s, id]));
  }

  const canStart = est && !est.truncated && est.calls > 0 && !busy && (mode !== "reuse" || sourceRun);

  return (
    <div className="bg-gray-900 border border-gray-800 rounded-xl p-4 space-y-4">
      <div className="flex flex-wrap items-end gap-4">
        <div>
          <label className="text-xs text-gray-400 block mb-1">From</label>
          <input type="datetime-local" value={from} max={to} onChange={(e) => setFrom(e.target.value)} className={input} />
        </div>
        <div>
          <label className="text-xs text-gray-400 block mb-1">To</label>
          <input type="datetime-local" value={to} min={from} onChange={(e) => setTo(e.target.value)} className={input} />
        </div>
        <div>
          <label className="text-xs text-gray-400 block mb-1">Label</label>
          <input value={label} onChange={(e) => setLabel(e.target.value)} placeholder="what changed?" className={`${input} w-56`} />
        </div>
      </div>

      <div className="space-y-1">
        {MODES.map((m) => (
          <label key={m.key} className="flex items-start gap-2 text-sm font-mono cursor-pointer">
            <input type="radio" checked={mode === m.key} onChange={() => setMode(m.key)} className="mt-1" />
            <span className="text-white">{m.label}</span>
            <span className="text-gray-500 text-xs mt-0.5">{m.help}</span>
          </label>
        ))}
      </div>

      {mode === "reuse" && (
        <div>
          <label className="text-xs text-gray-400 block mb-1">Reuse extraction from</label>
          <select value={sourceRun} onChange={(e) => setSourceRun(e.target.value)} className={input}>
            <option value="">— pick a finished run —</option>
            {sources.map((r) => (
              <option key={r.run_id} value={r.run_id}>
                {r.label || r.run_id} · {fmtTime(r.date_from)} → {fmtTime(r.date_to)}
              </option>
            ))}
          </select>
          <p className="text-xs text-gray-500 mt-1">Set the range to match that run; calls outside it are skipped.</p>
        </div>
      )}

      {systems.length > 1 && (
        <div className="flex flex-wrap gap-3">
          <span className="text-xs text-gray-400">Systems (none = all):</span>
          {systems.map((s) => (
            <label key={s.system_id} className="flex items-center gap-1 text-xs font-mono text-gray-300 cursor-pointer">
              <input type="checkbox" checked={systemIds.includes(s.system_id)} onChange={() => toggleSystem(s.system_id)} />
              {s.name}
            </label>
          ))}
        </div>
      )}

      <div className="flex flex-wrap items-center gap-3">
        <button onClick={estimate} disabled={working} className={btn}>{working && !est ? "Counting…" : "Estimate"}</button>
        <button
          onClick={start}
          disabled={!canStart || working}
          className="bg-indigo-600 hover:bg-indigo-500 disabled:opacity-50 text-white text-sm font-mono px-4 py-1.5 rounded-lg transition-colors"
        >
          Start run
        </button>
        {busy && <span className="text-xs text-amber-400 font-mono">a run is in progress</span>}
      </div>

      {est && (
        <p className="text-sm font-mono text-gray-300">
          {est.truncated ? (
            <span className="text-red-400">More than {est.max_calls} calls — narrow the range.</span>
          ) : (
            <>
              <span className="text-white">{est.calls}</span> calls ·{" "}
              {est.calls_with_transcript} with transcripts · {est.audio_minutes} audio min ·{" "}
              <span className="text-amber-400">~${est.est_cost_usd.toFixed(2)}</span> est.
              {mode === "transcripts" && est.calls_with_transcript < est.calls / 2 && (
                <span className="text-amber-400"> — most calls have no transcript; consider Re-transcribe audio.</span>
              )}
            </>
          )}
        </p>
      )}

      {error && <p className="text-red-400 text-sm font-mono">{error}</p>}
    </div>
  );
}

// ---------------------------------------------------------------------------

function RunsTable({
  runs, activeId, selected, onSelect, onChanged,
}: {
  runs: ReplayRun[]; activeId: string | null; selected: string | null;
  onSelect: (id: string) => void; onChanged: () => void;
}) {
  async function cancel(id: string) {
    await c2api.cancelReplay(id).catch(() => undefined);
    onChanged();
  }
  async function remove(id: string) {
    if (!window.confirm("Delete this run and its sandbox incidents?")) return;
    await c2api.deleteReplay(id).catch(() => undefined);
    onChanged();
  }

  if (!runs.length) return <p className="text-sm text-gray-500 font-mono">No runs yet.</p>;

  const th = "text-left text-xs text-gray-500 font-normal px-2 py-1.5 whitespace-nowrap";
  const td = "px-2 py-1.5 whitespace-nowrap";
  return (
    <div className="overflow-x-auto">
      <table className="w-full text-sm font-mono">
        <thead>
          <tr className="border-b border-gray-800">
            <th className={th}>Run</th>
            <th className={th}>Range</th>
            <th className={th}>Status</th>
            <th className={th} title="Incidents created">Inc</th>
            <th className={th} title="Share of incidents that are a single call">1-call</th>
            <th className={th} title="Calls that never linked to an incident">Orphans</th>
            <th className={th} title="Closed by radio traffic (units cleared, closure, reassignment) vs the idle timer">Real clears / timeouts</th>
            <th className={th} title="Correlation decisions the LLM took part in">LLM</th>
            <th className={th}>Cost</th>
            <th className={th}></th>
          </tr>
        </thead>
        <tbody>
          {runs.map((r) => {
            const m = r.metrics;
            const running = r.run_id === activeId;
            return (
              <tr
                key={r.run_id}
                onClick={() => onSelect(r.run_id)}
                className={`border-b border-gray-800/60 cursor-pointer ${selected === r.run_id ? "bg-gray-800/60" : "hover:bg-gray-900"}`}
              >
                <td className={td}>
                  <div className="text-white">{r.label || r.run_id}</div>
                  <div className="text-xs text-gray-500">{r.mode} · {r.git_sha?.slice(0, 7)} · {fmtTime(r.created_at)}</div>
                </td>
                <td className={`${td} text-xs text-gray-400`}>{fmtTime(r.date_from)} → {fmtTime(r.date_to)}</td>
                <td className={td}>
                  {running ? (
                    <span className="text-amber-400">{r.progress.done}/{r.progress.total}</span>
                  ) : (
                    <span className={r.status === "done" ? "text-green-400" : "text-red-400"}>{r.status}</span>
                  )}
                  {r.progress.errors > 0 && <span className="text-red-400 text-xs"> · {r.progress.errors} err</span>}
                </td>
                <td className={td}>{m?.incidents ?? "—"}</td>
                <td className={td}>{m?.single_call_pct != null ? `${m.single_call_pct}%` : "—"}</td>
                <td className={td}>{m ? `${m.calls_orphaned}/${m.calls}` : "—"}</td>
                <td className={td}>
                  {m ? (
                    <>
                      <span className="text-green-400">{sum(m.resolved_via, SIGNAL_RESOLVES)}</span>
                      {" / "}
                      <span className="text-gray-400">{m.resolved_via.idle_timeout ?? 0}</span>
                    </>
                  ) : "—"}
                </td>
                <td className={td}>{m?.llm_decisions ?? "—"}</td>
                <td className={td}>{m ? `$${m.est_cost_usd.toFixed(2)}` : `~$${r.estimate.est_cost_usd.toFixed(2)}`}</td>
                <td className={td} onClick={(e) => e.stopPropagation()}>
                  {running ? (
                    <button onClick={() => cancel(r.run_id)} className="text-xs text-amber-400 hover:text-amber-300">cancel</button>
                  ) : (
                    <button onClick={() => remove(r.run_id)} className="text-xs text-gray-500 hover:text-red-400">delete</button>
                  )}
                </td>
              </tr>
            );
          })}
        </tbody>
      </table>
    </div>
  );
}

// ---------------------------------------------------------------------------

function CallLine({ call }: { call: ReplayCallRow }) {
  const [audio, setAudio] = useState<string | null>(null);
  async function play() {
    try {
      const c = await c2api.getCall(call.call_id);
      setAudio(c.audio_url);
    } catch { /* audio is a convenience */ }
  }
  return (
    <div className="py-1.5 border-t border-gray-800/60 text-xs font-mono">
      <div className="flex flex-wrap gap-2 text-gray-500">
        <span>{fmtTime(call.started_at)}</span>
        <span>{call.talkgroup_name}</span>
        {call.corr_path.map((p, i) => <span key={i} className="text-indigo-400">{p}</span>)}
        {call.units?.length ? <span>units {call.units.join(", ")}</span> : null}
        {call.cleared_units?.length ? <span className="text-green-400">cleared {call.cleared_units.join(", ")}</span> : null}
        {call.skip_reason && <span className="text-gray-600">{call.skip_reason}</span>}
        {audio ? (
          <audio src={audio} controls autoPlay className="h-6" />
        ) : (
          <button onClick={play} className="text-gray-400 hover:text-white">▶ audio</button>
        )}
      </div>
      <div className="text-gray-200 mt-0.5">{call.transcript || <span className="text-gray-600">(no transcript)</span>}</div>
    </div>
  );
}

function IncidentCard({ inc }: { inc: ReplayIncident }) {
  const [open, setOpen] = useState(false);
  const signal = inc.resolved_via && SIGNAL_RESOLVES.includes(inc.resolved_via);
  return (
    <div className="bg-gray-900 border border-gray-800 rounded-lg px-3 py-2">
      <button onClick={() => setOpen(!open)} className="w-full text-left flex flex-wrap items-center gap-x-3 gap-y-1 text-sm font-mono">
        <span className="text-gray-500">{open ? "▾" : "▸"}</span>
        <span className="text-white">{inc.title || inc.incident_id}</span>
        <span className="text-gray-500 text-xs">{inc.calls.length} call{inc.calls.length !== 1 ? "s" : ""}</span>
        <span className="text-gray-500 text-xs">{fmtTime(inc.started_at)} → {fmtTime(inc.resolved_at)}</span>
        <span className={`text-xs ${signal ? "text-green-400" : "text-gray-500"}`}>{inc.resolved_via ?? inc.status}</span>
        {inc.location_coords && <span className="text-xs text-indigo-400">📍 {inc.location}</span>}
      </button>
      {open && <div className="mt-2">{inc.calls.map((c) => <CallLine key={c.call_id} call={c} />)}</div>}
    </div>
  );
}

function RunDetail({ run }: { run: ReplayRun }) {
  const [data, setData] = useState<ReplayIncidents | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [filter, setFilter] = useState<"all" | "multi" | "single">("all");
  const [showOrphans, setShowOrphans] = useState(false);

  useEffect(() => {
    setData(null); setError(null);
    if (run.status === "running") return;
    c2api.getReplayIncidents(run.run_id).then(setData).catch((e) => setError(String(e)));
  }, [run.run_id, run.status]);

  const m = run.metrics;
  const shown = (data?.incidents ?? []).filter((i) =>
    filter === "all" ? true : filter === "multi" ? i.calls.length > 1 : i.calls.length === 1,
  );

  return (
    <div className="space-y-3">
      {m && (
        <div className="grid grid-cols-2 sm:grid-cols-4 gap-2 text-xs font-mono">
          {[
            ["Linked calls", `${m.calls_linked}/${m.calls}`],
            ["Median calls / incident", m.median_calls_per_incident ?? "—"],
            ["With units cleared", m.incidents_with_units_cleared],
            ["With map pin", m.incidents_with_coords],
          ].map(([k, v]) => (
            <div key={k as string} className="bg-gray-900 border border-gray-800 rounded-lg p-2">
              <div className="text-gray-500">{k}</div>
              <div className="text-white text-base">{v}</div>
            </div>
          ))}
        </div>
      )}
      {m && (
        <p className="text-xs font-mono text-gray-500">
          resolved: {Object.entries(m.resolved_via).map(([k, v]) => `${k} ${v}`).join(" · ")}
          <br />
          paths: {Object.entries(m.corr_path).map(([k, v]) => `${k} ${v}`).join(" · ")}
        </p>
      )}
      {run.errors?.length > 0 && (
        <details className="text-xs font-mono text-red-400">
          <summary>{run.errors.length} error(s)</summary>
          {run.errors.map((e, i) => <div key={i}>{e}</div>)}
        </details>
      )}
      {run.status === "running" && <p className="text-sm text-gray-500 font-mono">Incidents appear when the run finishes.</p>}
      {error && <p className="text-red-400 text-sm font-mono">{error}</p>}
      {data && (
        <>
          <div className="flex gap-1 text-xs font-mono">
            {(["all", "multi", "single"] as const).map((f) => (
              <button
                key={f}
                onClick={() => setFilter(f)}
                className={`px-3 py-1 rounded-md ${filter === f ? "bg-gray-800 text-white" : "text-gray-500 hover:text-gray-300"}`}
              >
                {f === "all" ? `All (${data.incidents.length})` : f === "multi" ? "Multi-call" : "Single-call"}
              </button>
            ))}
            <button
              onClick={() => setShowOrphans(!showOrphans)}
              className={`px-3 py-1 rounded-md ${showOrphans ? "bg-gray-800 text-white" : "text-gray-500 hover:text-gray-300"}`}
            >
              Orphans ({data.orphans.length})
            </button>
          </div>
          {showOrphans ? (
            <div className="bg-gray-900 border border-gray-800 rounded-lg px-3 py-2">
              {data.orphans.map((c) => <CallLine key={c.call_id} call={c} />)}
            </div>
          ) : (
            <div className="space-y-1.5">{shown.map((i) => <IncidentCard key={i.incident_id} inc={i} />)}</div>
          )}
        </>
      )}
    </div>
  );
}

// ---------------------------------------------------------------------------

export function ReplayTab() {
  const [runs, setRuns] = useState<ReplayRun[]>([]);
  const [activeId, setActiveId] = useState<string | null>(null);
  const [selected, setSelected] = useState<string | null>(null);
  const [error, setError] = useState<string | null>(null);

  const load = useCallback(async () => {
    try {
      const res = await c2api.listReplays();
      setRuns(res.runs);
      setActiveId(res.active_run_id);
      setError(null);
    } catch (e) { setError(String(e)); }
  }, []);

  useEffect(() => { load(); }, [load]);
  // Poll only while something is running.
  useEffect(() => {
    if (!activeId) return;
    const t = setInterval(load, 4000);
    return () => clearInterval(t);
  }, [activeId, load]);

  const run = runs.find((r) => r.run_id === selected) ?? null;

  return (
    <div className="space-y-5">
      <p className="text-xs text-gray-500 font-mono">
        Re-run the pipeline over a past time range, in the calls&apos; original order, into a sandbox — live incidents are never
        touched. Replay the same range after each change and compare the rows below. A run starts with no incidents
        open, so its first ~90 minutes split more than live did — compare runs over the same range, not a run against live.
      </p>
      <NewRunForm runs={runs} busy={!!activeId} onStarted={load} />
      {error && <p className="text-red-400 text-sm font-mono">{error}</p>}
      <RunsTable runs={runs} activeId={activeId} selected={selected} onSelect={setSelected} onChanged={load} />
      {run && <RunDetail run={run} />}
    </div>
  );
}