"use client";

// ============================================================
// AI Assistant — "Lynk AI", a creative conversational copilot.
//   · Empty state : warm greeting, capability cards, prompt chips
//   · Active chat : message thread with a typing indicator and a
//                   simulated, keyword-aware assistant reply
//   · Composer    : auto-suggesting prompt row + send / new chat
// All responses are canned + client-side so it demos with no API.
// ============================================================

import { useEffect, useRef, useState } from "react";
import { user } from "./account-data";
import { Avatar, Btn, Icon, Pill, useToast } from "./ui";

type Msg = { id: number; from: "me" | "ai"; text: string };

const CAPABILITIES = [
  { icon: "leads", tone: "var(--orange)", title: "Qualify leads", desc: "Score and summarise new leads, draft the first outreach." },
  { icon: "estimates", tone: "var(--blue)", title: "Build estimates", desc: "Turn scope notes into a clean, line-itemed proposal." },
  { icon: "schedule", tone: "var(--green)", title: "Plan the week", desc: "Suggest a crew schedule around weather and priorities." },
  { icon: "leaderboard", tone: "var(--purple)", title: "Analyse pipeline", desc: "Spot stalled deals and where revenue is leaking." },
];

const PROMPTS = [
  { icon: "leads", text: "Summarise my new leads from this week" },
  { icon: "estimates", text: "Draft an estimate for a 28-square asphalt reroof" },
  { icon: "storm", text: "Which territories were hit by the last storm?" },
  { icon: "pipeline", text: "Show deals stuck in the pipeline over 14 days" },
];

let msgSeq = 1;

export function AiAssistant() {
  const toast = useToast();
  const [messages, setMessages] = useState<Msg[]>([]);
  const [draft, setDraft] = useState("");
  const [typing, setTyping] = useState(false);
  const scrollRef = useRef<HTMLDivElement | null>(null);
  const timer = useRef<ReturnType<typeof setTimeout> | null>(null);

  const started = messages.length > 0;

  useEffect(() => {
    scrollRef.current?.scrollTo({ top: scrollRef.current.scrollHeight, behavior: "smooth" });
  }, [messages, typing]);

  useEffect(() => () => { if (timer.current) clearTimeout(timer.current); }, []);

  function send(text: string) {
    const body = text.trim();
    if (!body || typing) return;
    setMessages((m) => [...m, { id: msgSeq++, from: "me", text: body }]);
    setDraft("");
    setTyping(true);
    timer.current = setTimeout(() => {
      setMessages((m) => [...m, { id: msgSeq++, from: "ai", text: replyFor(body) }]);
      setTyping(false);
    }, 1100);
  }

  function reset() {
    if (timer.current) clearTimeout(timer.current);
    setMessages([]); setDraft(""); setTyping(false);
  }

  return (
    <div className="view ai-view">
      <div className="ai-head">
        <div className="ai-head-l">
          <span className="ai-mark"><Icon name="ai" size={20} /></span>
          <div>
            <div className="ai-eyebrow">LynkedUp Pro</div>
            <h1>Lynk AI <Pill tone="orange">Beta</Pill></h1>
          </div>
        </div>
        <div className="ai-head-actions">
          <span className="ai-model"><span className="ai-model-dot" /> Opus 4.8</span>
          {started && <Btn variant="outline" size="sm" icon="plus" onClick={reset}>New chat</Btn>}
        </div>
      </div>

      <div className="ai-stage card card-pad-0">
        <div className="ai-scroll" ref={scrollRef}>
          {!started ? (
            <div className="ai-hero">
              <div className="ai-orb-wrap">
                <span className="ai-orb-ring" aria-hidden />
                <span className="ai-orb-ring d2" aria-hidden />
                <span className="ai-orb-ring d3" aria-hidden />
                <span className="ai-hero-orb"><Icon name="ai" size={34} /></span>
              </div>
              <h2>{greeting()}, {user.firstName}.</h2>
              <p>I&apos;m your roofing copilot. Ask me to summarise leads, draft estimates, plan crews or dig into your pipeline.</p>

              <div className="ai-caps">
                {CAPABILITIES.map((c) => (
                  <button className="ai-cap" key={c.title} style={{ ["--rc" as string]: c.tone }} onClick={() => send(`Help me ${c.title.toLowerCase()}`)}>
                    <span className="ai-cap-ic"><Icon name={c.icon} size={18} /></span>
                    <span className="ai-cap-title">{c.title}</span>
                    <span className="ai-cap-desc">{c.desc}</span>
                  </button>
                ))}
              </div>

              <div className="ai-suggest">
                <span className="ai-suggest-lbl">Try asking</span>
                <div className="ai-chips">
                  {PROMPTS.map((p) => (
                    <button className="ai-chip" key={p.text} onClick={() => send(p.text)}>
                      <Icon name={p.icon} size={14} /> {p.text}
                    </button>
                  ))}
                </div>
              </div>
            </div>
          ) : (
            <div className="ai-thread">
              {messages.map((m) => (
                <div className={`ai-msg ${m.from}`} key={m.id}>
                  {m.from === "ai"
                    ? <span className="ai-msg-av ai-mark"><Icon name="ai" size={16} /></span>
                    : <Avatar initials={user.initials} gradient={user.avatarGradient} size={32} />}
                  <div className="ai-bubble">
                    {m.text.split("\n").map((line, i) => <p key={i}>{line}</p>)}
                    {m.from === "ai" && (
                      <div className="ai-msg-actions">
                        <button onClick={() => { navigator.clipboard?.writeText(m.text); toast.push({ tone: "success", title: "Copied to clipboard" }); }} aria-label="Copy"><Icon name="copy" size={13} /></button>
                        <button onClick={() => toast.push({ tone: "success", title: "Thanks for the feedback" })} aria-label="Good response"><Icon name="check" size={13} /></button>
                      </div>
                    )}
                  </div>
                </div>
              ))}
              {typing && (
                <div className="ai-msg ai">
                  <span className="ai-msg-av ai-mark"><Icon name="ai" size={16} /></span>
                  <div className="ai-bubble ai-typing"><span /><span /><span /></div>
                </div>
              )}
            </div>
          )}
        </div>

        <div className="ai-composer">
          {started && (
            <div className="ai-quickrow">
              {PROMPTS.slice(0, 3).map((p) => (
                <button key={p.text} className="ai-quick" onClick={() => send(p.text)}><Icon name={p.icon} size={13} /> {p.text}</button>
              ))}
            </div>
          )}
          <div className="ai-inputbar">
            <button className="ai-attach" aria-label="Attach" onClick={() => toast.push({ tone: "info", title: "Attachments", desc: "File uploads land here soon." })}><Icon name="paperclip" size={18} /></button>
            <textarea
              className="ai-textarea"
              rows={1}
              placeholder="Ask Lynk AI anything about your roofing business…"
              value={draft}
              onChange={(e) => setDraft(e.target.value)}
              onKeyDown={(e) => { if (e.key === "Enter" && !e.shiftKey) { e.preventDefault(); send(draft); } }}
            />
            <button className="ai-send" aria-label="Send" disabled={!draft.trim() || typing} onClick={() => send(draft)}><Icon name="send" size={17} /></button>
          </div>
          <div className="ai-foot">Lynk AI can make mistakes. Verify estimates and figures before sending to owners.</div>
        </div>
      </div>
    </div>
  );
}

/* ---------------------------------------------------------- */
/* helpers                                                     */
/* ---------------------------------------------------------- */

function greeting(): string {
  // Deterministic across renders to avoid hydration drift — anchored to a
  // fixed demo time-of-day rather than the live clock.
  return "Good evening";
}

// Lightweight keyword router so the demo feels responsive without an API.
function replyFor(q: string): string {
  const t = q.toLowerCase();
  if (t.includes("lead")) {
    return "You have 6 new leads this week — 4 inbound from the storm landing page and 2 referrals.\nTop priority: Mark Reynolds (Sector 18) — full roof replacement, insurance claim already filed. I've drafted a first-touch SMS; want me to queue it?";
  }
  if (t.includes("estimate") || t.includes("proposal") || t.includes("reroep") || t.includes("reroof")) {
    return "Here's a starting estimate for a 28-square asphalt reroof:\n• Tear-off & disposal — $3,920\n• Architectural shingles (28 sq) — $7,560\n• Underlayment, flashing & ridge vent — $2,180\n• Labour (3-day crew) — $5,400\nSubtotal $19,060 · 10% margin → $20,966. Want it itemised into a sendable proposal?";
  }
  if (t.includes("schedule") || t.includes("crew") || t.includes("week") || t.includes("plan")) {
    return "Clear weather Tue–Thu, rain Friday. Suggested plan:\n• Tue: Crew A → 181 Sector 18 (reroof, day 1)\n• Wed: Crew A continues; Crew B → inspections in Pocket B\n• Thu: finish 181, start estimates follow-ups\nShould I block these in Team Schedule?";
  }
  if (t.includes("storm") || t.includes("territory") || t.includes("weather")) {
    return "Last cell tracked through Sectors 14, 18 and Pocket B on 26 Jun with 1.5\" hail. 23 owners in those zones are good storm-canvass targets — 9 already have open claims. Want a canvass route?";
  }
  if (t.includes("pipeline") || t.includes("stuck") || t.includes("stall") || t.includes("deal")) {
    return "3 deals have been idle over 14 days:\n• Bennett reroof — $21k, no contact in 18 days\n• Foster gutters — $4.2k, awaiting estimate\n• Turner inspection — booked, never closed\nThe Bennett deal is your biggest risk. Draft a re-engagement email?";
  }
  return "Got it. I can pull leads, build estimates, plan crew schedules, read storm/territory data and analyse your pipeline. Tell me which one to start with, or ask a specific question and I'll dig in.";
}