import { useEffect, useMemo, useRef, useState } from "react";
import {
  Buildings, MagnifyingGlass, FilePdf, Database, ArrowRight,
  DownloadSimple, WarningCircle, CheckCircle,
} from "@phosphor-icons/react";
import { api, type Company, type RunSummary, ApiError } from "../lib/api";
import { ErrorNote, TableSkeleton, Empty, Spinner, Note } from "./common";

interface Hit {
  scrip_code: string;
  name: string;
  issuer_name: string;
  isin: string | null;
  industry: string;
  group: string;
  market_cap: string | null;
  is_sme: boolean;
  prepared: boolean;
  has_filing?: boolean | null;
  filing_year?: string | null;
}

interface IngestEvent { stage: string; detail: string; pct: number; at: number }

export function Intake({ onStarted, embedded = false }:
  { onStarted: (run: RunSummary) => void; embedded?: boolean }) {
  const [q, setQ] = useState("");
  const [scope, setScope] = useState<"sme" | "all">("sme");
  const [hits, setHits] = useState<Hit[] | null>(null);
  const [universe, setUniverse] = useState<Record<string, number> | null>(null);
  const [prepared, setPrepared] = useState<Record<string, Company>>({});
  const [error, setError] = useState<string | null>(null);
  const [searchErr, setSearchErr] = useState<string | null>(null);
  const [sel, setSel] = useState<Hit | null>(null);
  const [starting, setStarting] = useState(false);

  // live ingestion
  const [job, setJob] = useState<{ id: string; status: string } | null>(null);
  const [events, setEvents] = useState<IngestEvent[]>([]);
  const [ingestErr, setIngestErr] = useState<string | null>(null);
  const es = useRef<EventSource | null>(null);

  useEffect(() => {
    api.companies()
      .then((r) => setPrepared(Object.fromEntries(r.companies.map((c) => [c.scrip_code, c]))))
      .catch(() => { /* live search still works without the prepared index */ });
  }, []);

  // Debounced live search against the real BSE master.
  useEffect(() => {
    const t = setTimeout(() => {
      setSearchErr(null);
      setHits(null);
      fetch(`/api/search?q=${encodeURIComponent(q)}&scope=${scope}&limit=40`)
        .then(async (r) => {
          if (!r.ok) throw new Error((await r.json()).detail ?? r.statusText);
          return r.json();
        })
        .then((d) => { setHits(d.results); setUniverse(d.universe); })
        .catch((e) => setSearchErr(String(e.message ?? e)));
    }, q ? 260 : 0);
    return () => clearTimeout(t);
  }, [q, scope]);

  useEffect(() => () => es.current?.close(), []);

  const selPrepared = sel ? prepared[sel.scrip_code] : undefined;
  const isReady = Boolean(sel && (sel.prepared || job?.status === "done"));

  const ingest = () => {
    if (!sel) return;
    setIngestErr(null);
    setEvents([]);
    setJob(null);
    api.ingest(sel.scrip_code, sel.name)
      .then((j) => {
        setJob({ id: j.id, status: j.status });
        es.current?.close();
        const src = new EventSource(`/api/ingest/${j.id}/stream`);
        es.current = src;
        src.addEventListener("progress", (e) =>
          setEvents((p) => [...p, JSON.parse((e as MessageEvent).data)]));
        src.addEventListener("done", (e) => {
          const d = JSON.parse((e as MessageEvent).data);
          setJob({ id: d.id, status: "done" });
          setPrepared((p) => ({ ...p, [d.summary.scrip_code]: d.summary as Company }));
          setHits((h) => h?.map((x) =>
            x.scrip_code === d.summary.scrip_code ? { ...x, prepared: true } : x) ?? null);
          src.close();
        });
        src.addEventListener("failed", (e) => {
          const d = JSON.parse((e as MessageEvent).data);
          setJob({ id: d.id, status: "failed" });
          setIngestErr(d.error);
          src.close();
        });
        src.onerror = () => src.close();
      })
      .catch((e) => setIngestErr(e instanceof ApiError ? e.message : String(e)));
  };

  const start = async () => {
    if (!sel) return;
    setStarting(true);
    setError(null);
    try {
      onStarted(await api.createRun(sel.scrip_code));
    } catch (e) {
      setError(e instanceof ApiError ? e.message : String(e));
      setStarting(false);
    }
  };

  const pct = events.length ? events[events.length - 1].pct : 0;

  return (
    <>
      {!embedded && (
        <div className="page-head">
          <h1 className="page">Find an issuer</h1>
          <p className="lede">
            Search every company listed on BSE. Records already read are available at once; any
            other issuer is ingested live, by downloading its actual annual report and parsing
            it.
          </p>
        </div>
      )}

      {error && <div style={{ marginBottom: 14 }}><ErrorNote message={error} /></div>}

      <div className="grid cols-sidebar">
        <section className="panel">
          <div className="panel-h">
            <Buildings size={16} />
            <h2>BSE issuers</h2>
            {universe && (
              <span className="count">
                {scope === "sme" ? universe.sme : universe.total} searchable ·
                {" "}{universe.prepared} already read
              </span>
            )}
            <div className="filters" style={{ marginLeft: "auto" }}>
              <button className="filter" aria-pressed={scope === "sme"}
                      onClick={() => setScope("sme")}>SME platform</button>
              <button className="filter" aria-pressed={scope === "all"}
                      onClick={() => setScope("all")}>all BSE</button>
            </div>
          </div>

          <div className="panel-b" style={{ paddingBottom: 12 }}>
            <label htmlFor="co-search" style={{ display: "none" }}>Search issuers</label>
            <div style={{ position: "relative" }}>
              <MagnifyingGlass size={15} style={{
                position: "absolute", left: 11, top: "50%",
                transform: "translateY(-50%)", color: "var(--text-3)",
              }} />
              <input
                id="co-search"
                className="ctl search"
                style={{ paddingLeft: 32 }}
                placeholder="Search by company name, BSE scrip code, ISIN or industry"
                value={q}
                onChange={(e) => setQ(e.target.value)}
                autoFocus
              />
            </div>
          </div>

          <div className="co-list">
            {searchErr && <div style={{ padding: 16 }}><ErrorNote message={searchErr} /></div>}
            {!hits && !searchErr && <TableSkeleton rows={9} />}
            {hits?.length === 0 && (
              <Empty icon={<MagnifyingGlass size={26} />} title="No issuer matches that search">
                Try a company name, a BSE scrip code, an ISIN, or switch to all of BSE.
              </Empty>
            )}
            {hits?.map((c) => {
              const p = prepared[c.scrip_code];
              return (
                <button
                  key={c.scrip_code}
                  className="co"
                  aria-pressed={sel?.scrip_code === c.scrip_code}
                  onClick={() => {
                    setSel(c);
                    setJob(null); setEvents([]); setIngestErr(null);
                  }}
                >
                  <span>
                    <span className="co-name">{c.name}</span>
                    <span className="co-meta">
                      scrip {c.scrip_code}
                      {p?.cin ? ` · ${p.cin}` : c.isin ? ` · ${c.isin}` : ""}
                      {c.industry ? ` · ${c.industry}` : ""}
                    </span>
                  </span>
                  <span className="co-tags">
                    {c.is_sme && <span className="tag tag-info">SME</span>}
                    {c.prepared || p ? (
                      <span className="tag tag-ok">read</span>
                    ) : c.has_filing === false ? (
                      <span className="tag">no filing yet</span>
                    ) : c.has_filing ? (
                      <span className="tag tag-warn">
                        filing {c.filing_year ?? ""}
                      </span>
                    ) : (
                      <span className="tag">not read yet</span>
                    )}
                  </span>
                </button>
              );
            })}
          </div>
        </section>

        <aside style={{ display: "grid", gap: 14 }}>
          {!sel ? (
            <div className="panel">
              <Empty icon={<Buildings size={26} />} title="No issuer selected">
                Choose an issuer to see the source records PrimaryDraft will read.
              </Empty>
            </div>
          ) : (
            <>
              <section className="panel">
                <div className="panel-h"><h2>{sel.name}</h2></div>
                <div className="panel-b" style={{ display: "grid", gap: 10 }}>
                  <Row k="BSE scrip" v={sel.scrip_code} />
                  <Row k="CIN" v={selPrepared?.cin ?? "read from the filing on ingest"} />
                  <Row k="ISIN" v={sel.isin ?? "not stated"} />
                  <Row k="Industry" v={sel.industry || "not stated"} />
                  <Row k="Platform" v={sel.is_sme ? `BSE SME (group ${sel.group})`
                                                  : `main board (group ${sel.group})`} />
                  {!sel.is_sme && (
                    <Note tone="warn">
                      This issuer is on the main board, not the SME platform. The engine will
                      still run, and the SME eligibility rules will report accordingly.
                    </Note>
                  )}
                </div>
              </section>

              {isReady ? (
                <>
                  <section className="panel">
                    <div className="panel-h"><h2>Source records</h2></div>
                    <div className="panel-b" style={{ display: "grid", gap: 12 }}>
                      <Source
                        icon={<FilePdf size={17} />}
                        title={`Annual Report ${selPrepared?.year ?? ""}`}
                        detail={selPrepared
                          ? `${selPrepared.pages} pages, filed with BSE. ${selPrepared.pl_fields} profit and loss fields and ${selPrepared.bs_fields} balance sheet fields were machine-readable.`
                          : "Read from the issuer's filing on BSE."}
                      />
                      <Source
                        icon={<Database size={17} />}
                        title="BSE scrip master"
                        detail={`Live exchange API. Scrip ${sel.scrip_code}, ISIN, face value, industry classification.`}
                      />
                      {selPrepared && (selPrepared.identities?.length ?? 0) > 0 ? (
                        <Note>
                          <b>{selPrepared.identities.length} accounting identities close</b> on
                          the statements read from this filing. A statement whose arithmetic does
                          not close is withheld rather than published.
                          <ul style={{ margin: "7px 0 0", paddingLeft: 17 }}>
                            {selPrepared.identities.map((i) => (
                              <li key={i} className="mono" style={{ fontSize: 11 }}>{i}</li>
                            ))}
                          </ul>
                        </Note>
                      ) : selPrepared ? (
                        <Note tone="warn">
                          No accounting identity closed on this filing, so the financial
                          statements were withheld. The ledger will be thin and the engine will
                          say so.
                        </Note>
                      ) : null}
                    </div>
                  </section>

                  <button className="btn btn-primary" onClick={start} disabled={starting}
                          style={{ justifyContent: "center", padding: "11px 18px" }}>
                    {starting ? <><Spinner /> Reading records</>
                              : <>Build disclosure ledger <ArrowRight size={15} /></>}
                  </button>
                </>
              ) : (
                <section className="panel">
                  <div className="panel-h"><h2>Ingest from BSE</h2></div>
                  <div className="panel-b" style={{ display: "grid", gap: 12 }}>
                    {!job && !ingestErr && (
                      sel.has_filing === false ? (
                        <Note tone="warn">
                          This issuer has no annual report filed on BSE, so there are no records
                          to read. Recently listed SME companies often have not filed their first
                          one yet. Pick an issuer showing a filing year.
                        </Note>
                      ) : (
                        <>
                          <Note tone="quiet">
                            This issuer has not been read yet. PrimaryDraft will download its
                            actual annual report{sel.filing_year ? ` (${sel.filing_year})` : ""} from
                            BSE and parse it. Filings run to a few hundred pages, so this takes a
                            little time.
                          </Note>
                          <button className="btn btn-primary" onClick={ingest}
                                  style={{ justifyContent: "center" }}>
                            <DownloadSimple size={15} /> Read this issuer's filing
                          </button>
                        </>
                      )
                    )}

                    {job && (
                      <>
                        <div className="bar"><i style={{ width: `${pct}%` }} /></div>
                        <div style={{ display: "grid", gap: 6 }}>
                          {events.map((e, i) => (
                            <div key={i} style={{
                              display: "grid", gridTemplateColumns: "auto 46px 1fr",
                              gap: 9, alignItems: "baseline", fontSize: 12,
                            }}>
                              <span style={{ color: "var(--accent)" }}>
                                {e.stage === "failed"
                                  ? <WarningCircle size={13} weight="fill" />
                                  : i === events.length - 1 && job.status === "running"
                                    ? <Spinner />
                                    : <CheckCircle size={13} weight="fill" />}
                              </span>
                              <span className="mono" style={{ fontSize: 10.5, color: "var(--text-3)" }}>
                                {e.at.toFixed(1)}s
                              </span>
                              <span style={{ color: "var(--text-2)", lineHeight: 1.45 }}>
                                {e.detail}
                              </span>
                            </div>
                          ))}
                        </div>
                      </>
                    )}

                    {ingestErr && (
                      <>
                        <ErrorNote message={ingestErr} />
                        <Note tone="quiet">
                          This is the honest outcome, not a bug. A filing with no text layer
                          cannot be cited, and PrimaryDraft will not build a ledger it cannot
                          defend. Pick another issuer.
                        </Note>
                      </>
                    )}
                  </div>
                </section>
              )}
            </>
          )}
        </aside>
      </div>
    </>
  );
}

function Row({ k, v }: { k: string; v: string }) {
  return (
    <div style={{ display: "grid", gridTemplateColumns: "88px 1fr", gap: 10, fontSize: 12.5 }}>
      <span style={{ color: "var(--text-2)" }}>{k}</span>
      <span className="mono" style={{ wordBreak: "break-all" }}>{v}</span>
    </div>
  );
}

function Source({ icon, title, detail }: { icon: React.ReactNode; title: string; detail: string }) {
  return (
    <div style={{ display: "grid", gridTemplateColumns: "auto 1fr", gap: 10 }}>
      <span style={{ color: "var(--accent)", marginTop: 1 }}>{icon}</span>
      <span>
        <div style={{ fontSize: 12.5, fontWeight: 500 }}>{title}</div>
        <div style={{ fontSize: 11.5, color: "var(--text-2)", lineHeight: 1.5, marginTop: 2 }}>
          {detail}
        </div>
      </span>
    </div>
  );
}