import { useEffect, useState } from "react";
import { IdentificationCard, ArrowRight, WarningCircle } from "@phosphor-icons/react";
import { api, type RunSummary, ApiError } from "../lib/api";
import { ErrorNote, Note, Spinner } from "./common";

interface Parsed {
  raw: string; valid: boolean; error: string;
  is_listed: boolean | null; industry_code: string; nic_division_name: string;
  state: string; state_code: string; year: number | null; age_years: number | null;
  ownership_code: string; ownership: string; is_public_company: boolean | null;
  registration_number: string; listing: string;
}

/** Intake for a pre-IPO issuer: no exchange history, so the CIN is the only
 *  record that exists until documents are supplied. */
export function CinIntake({ onStarted }: { onStarted: (run: RunSummary) => void }) {
  const [cin, setCin] = useState("");
  const [name, setName] = useState("");
  const [parsed, setParsed] = useState<Parsed | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [starting, setStarting] = useState(false);

  useEffect(() => {
    const v = cin.trim().toUpperCase();
    if (v.length < 21) { setParsed(null); return; }
    const t = setTimeout(() => {
      api.inspectCin(v).then(setParsed).catch(() => setParsed(null));
    }, 150);
    return () => clearTimeout(t);
  }, [cin]);

  const start = async () => {
    setStarting(true); setError(null);
    try {
      onStarted(await api.createRunFromCin(cin.trim().toUpperCase(), name));
    } catch (e) {
      setError(e instanceof ApiError ? e.message : String(e));
      setStarting(false);
    }
  };

  const seg = (label: string, value: string, chars: string) => (
    <div style={{ display: "grid", gridTemplateColumns: "116px 1fr", gap: 10, fontSize: 12.5 }}>
      <span style={{ color: "var(--text-2)" }}>{label}</span>
      <span>
        <span className="mono">{value}</span>
        <span className="f-id" style={{ display: "block", marginTop: 1 }}>{chars}</span>
      </span>
    </div>
  );

  return (
    <div className="grid cols-sidebar">
      <section className="panel">
        <div className="panel-h">
          <IdentificationCard size={16} />
          <h2>Pre-IPO issuer</h2>
        </div>
        <div className="panel-b">
          <Note tone="quiet">
            An unlisted company has no exchange filing history, so it cannot be found by
            search. Its Corporate Identity Number is a real registry identifier and settles
            several eligibility questions on its own. Financial disclosures stay absent until
            documents are supplied, and the draft will say so rather than fill them in.
          </Note>

          <div className="field" style={{ marginTop: 14 }}>
            <label htmlFor="cin">Corporate Identity Number</label>
            <input id="cin" className="ctl" placeholder="U62090KA2025PTC207753"
                   maxLength={21} value={cin}
                   onChange={(e) => setCin(e.target.value.toUpperCase())} />
            <div className="help">21 characters, as issued by the Ministry of Corporate Affairs.</div>
          </div>

          <div className="field">
            <label htmlFor="coname">Registered name (optional)</label>
            <input id="coname" className="ctl" style={{ fontFamily: "var(--sans)" }}
                   placeholder="As on the certificate of incorporation"
                   value={name} onChange={(e) => setName(e.target.value)} />
            <div className="help">
              Recorded as unverified: a name typed by hand is not corroborated by any register.
            </div>
          </div>

          {cin.trim().length >= 21 && parsed && !parsed.valid && (
            <ErrorNote message={parsed.error} />
          )}

          {error && <div style={{ marginTop: 12 }}><ErrorNote message={error} /></div>}

          <button className="btn btn-primary" onClick={start}
                  disabled={!parsed?.valid || starting}
                  style={{ width: "100%", justifyContent: "center", marginTop: 6 }}>
            {starting ? <><Spinner /> Building ledger</>
                      : <>Build disclosure ledger <ArrowRight size={15} /></>}
          </button>
        </div>
      </section>

      <aside style={{ display: "grid", gap: 14 }}>
        {parsed?.valid ? (
          <>
            <section className="panel">
              <div className="panel-h"><h2>What the identifier encodes</h2></div>
              <div className="panel-b" style={{ display: "grid", gap: 10 }}>
                {seg("Listing", parsed.is_listed ? "Listed" : "Unlisted",
                     `letter ${parsed.listing}, character 1`)}
                {seg("Industry", `${parsed.industry_code}`,
                     parsed.nic_division_name)}
                {seg("Registrar", parsed.state, `code ${parsed.state_code}`)}
                {seg("Incorporated", String(parsed.year ?? ""),
                     `${parsed.age_years} year(s) ago`)}
                {seg("Class", parsed.ownership, `code ${parsed.ownership_code}`)}
                {seg("Registration", parsed.registration_number, "with the Registrar")}
              </div>
            </section>

            {parsed.is_public_company === false && (
              <Note tone="warn">
                <b>A private company cannot make a public issue.</b> The engine will report
                this as a blocker: conversion to a public limited company under the Companies
                Act is a prerequisite, not a drafting fix.
              </Note>
            )}
            {parsed.year !== null && new Date().getFullYear() - parsed.year < 3 && (
              <Note tone="warn">
                <b>Incorporated {parsed.year}.</b> Regulation 229(6) tests operating profit in
                two of the last three financial years. The engine will report whether enough
                financial years can have closed.
              </Note>
            )}
          </>
        ) : (
          <div className="panel">
            <div className="panel-b">
              <div style={{ fontSize: 12.5, color: "var(--text-2)", lineHeight: 1.6 }}>
                Enter a Corporate Identity Number to see what it encodes. Every one of its
                21 characters means something.
              </div>
              <pre className="mono" style={{
                fontSize: 11, lineHeight: 1.7, color: "var(--text-3)",
                marginTop: 12, whiteSpace: "pre-wrap",
              }}>{`U 62090 KA 2025 PTC 207753
│   │    │   │    │    └ registration no.
│   │    │   │    └ class of company
│   │    │   └ year of incorporation
│   │    └ state of the registrar
│   └ NIC industry code
└ L listed, U unlisted`}</pre>
            </div>
          </div>
        )}
      </aside>
    </div>
  );
}