"use client";

import { useEffect, useMemo, useState } from "react";
import Link from "next/link";
import { Building2, MapPin, Pencil, Plus, UserPlus, X } from "lucide-react";
import { Avatar } from "./Avatar";
import { currentUser, people } from "@/lib/demo-data";
import { useCurrentUser } from "@/lib/client-session";

type ProfilePerson = {
  id: string;
  name: string;
  username: string;
  headline: string;
  about: string;
  location: string;
  avatarUrl?: string | null;
};

type Experience = {
  id: string;
  companyName: string;
  title: string;
  location: string;
  description: string;
  startDate: string;
  endDate?: string | null;
  current: boolean;
};

const demoExperiences: Experience[] = [
  { id: "demo-northstar", companyName: "Northstar Systems", title: "Product Design Lead", location: "San Francisco Bay Area · Hybrid", description: "Leading design for workflow infrastructure used by operations teams around the world.", startDate: "2022-01", current: true },
  { id: "demo-pattern", companyName: "Pattern Digital", title: "Senior Product Designer", location: "Oakland, California", description: "", startDate: "2019-01", endDate: "2022-01", current: false },
];

function initialPerson(username: string): ProfilePerson {
  const match = username === currentUser.username ? currentUser : people.find((item) => item.username === username) ?? people[0];
  return {
    id: match.id,
    name: match.name,
    username: match.username,
    headline: match.headline,
    about: "I design products and teams around clarity. My work focuses on complex professional tools, service design, and the operating systems that help multidisciplinary groups make good decisions together.",
    location: username === currentUser.username ? currentUser.location : "New York City Metropolitan Area",
    avatarUrl: match.avatar,
  };
}

export function ProfileView({ username }: { username: string }) {
  const sessionUser = useCurrentUser();
  const [person, setPerson] = useState<ProfilePerson>(() => initialPerson(username));
  const [experienceRows, setExperienceRows] = useState<Experience[]>(demoExperiences);
  const [connectionStatusById, setConnectionStatusById] = useState<Record<string, "pending" | "accepted">>({});
  const [connectingId, setConnectingId] = useState<string | null>(null);
  const [connectionError, setConnectionError] = useState("");
  const [profileOpen, setProfileOpen] = useState(false);
  const [experienceOpen, setExperienceOpen] = useState(false);
  const [saving, setSaving] = useState(false);
  const [formError, setFormError] = useState("");
  const [profileDraft, setProfileDraft] = useState({ name: person.name, headline: person.headline, location: person.location, about: person.about });
  const [experienceDraft, setExperienceDraft] = useState({ title: "", companyName: "", location: "", startDate: "2026-08", description: "" });
  const mine = username === sessionUser.username;
  const suggestionPeople = useMemo(() => people.filter((item) => item.id !== person.id), [person.id]);

  useEffect(() => {
    let active = true;
    void fetch(`/api/profile/${encodeURIComponent(username)}`, { cache: "no-store" })
      .then(async (response) => {
        const body = await response.json() as { user?: ProfilePerson, experiences?: Experience[] };
        if (!active || !response.ok || !body.user) return;
        setPerson(body.user);
        setProfileDraft({ name: body.user.name, headline: body.user.headline, location: body.user.location, about: body.user.about });
        setExperienceRows(body.experiences ?? []);
      })
      .catch(() => undefined);
    return () => { active = false; };
  }, [username]);

  async function requestConnection(recipientId: string) {
    if (connectingId || connectionStatusById[recipientId]) return;
    setConnectingId(recipientId);
    setConnectionError("");
    try {
      const response = await fetch("/api/connections", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ recipientId }) });
      const result = await response.json().catch(() => ({})) as { connection?: { id?: string, status?: "pending" | "accepted" | "declined" }, error?: string };
      if (!response.ok || !result.connection?.id) throw new Error(result.error ?? "Unable to send this connection request.");
      const status = result.connection.status === "accepted" ? "accepted" : "pending";
      setConnectionStatusById((items) => ({ ...items, [recipientId]: status }));
    } catch (caught) {
      setConnectionError(caught instanceof Error ? caught.message : "Unable to send this connection request.");
    } finally {
      setConnectingId(null);
    }
  }

  function connectionLabel(recipientId: string) {
    if (connectingId === recipientId) return "Sending…";
    if (connectionStatusById[recipientId] === "accepted") return "Connected";
    if (connectionStatusById[recipientId] === "pending") return "Pending";
    return "Connect";
  }

  function connectionDisabled(recipientId: string) {
    return Boolean(connectingId === recipientId || connectionStatusById[recipientId]);
  }

  async function saveProfile() {
    if (saving) return;
    setSaving(true);
    setFormError("");
    try {
      const response = await fetch("/api/profile", { method: "PATCH", headers: { "content-type": "application/json" }, body: JSON.stringify(profileDraft) });
      const result = await response.json().catch(() => ({})) as { user?: ProfilePerson, error?: string };
      if (!response.ok || !result.user) throw new Error(result.error ?? "Unable to save your profile.");
      setPerson(result.user);
      setProfileOpen(false);
    } catch (caught) {
      setFormError(caught instanceof Error ? caught.message : "Unable to save your profile.");
    } finally {
      setSaving(false);
    }
  }

  async function addExperience() {
    if (saving) return;
    setSaving(true);
    setFormError("");
    try {
      const response = await fetch("/api/profile/experiences", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ ...experienceDraft, current: true }) });
      const result = await response.json().catch(() => ({})) as { experience?: Experience, error?: string };
      if (!response.ok || !result.experience) throw new Error(result.error ?? "Unable to add this experience.");
      setExperienceRows((items) => [result.experience!, ...items]);
      setExperienceDraft({ title: "", companyName: "", location: "", startDate: "2026-08", description: "" });
      setExperienceOpen(false);
    } catch (caught) {
      setFormError(caught instanceof Error ? caught.message : "Unable to add this experience.");
    } finally {
      setSaving(false);
    }
  }

  return (
    <div className="profile-layout">
      <div className="profile-main">
        <section className="surface profile-hero">
          <div className="profile-cover"><img src="/media/profile-cover.jpg" alt="" /></div>
          <div className="profile-intro">
            <Avatar name={person.name} src={person.avatarUrl ?? undefined} size="xl" />
            {mine && <button className="icon-button profile-edit" aria-label="Edit intro" onClick={() => { setFormError(""); setProfileOpen(true); }}><Pencil size={19} /></button>}
            <h1>{person.name}</h1>
            <p>{person.headline || "Add a headline to tell your network what you do."}</p>
            <span><MapPin size={15} /> {person.location || "Add your location"} · <a href="#">Contact info</a></span>
            <b>482 connections</b>
            <div className="profile-actions">
              {mine ? <><button className="button button-primary">Open to</button><button className="button button-outline" onClick={() => setExperienceOpen(true)}>Add profile section</button><button className="button button-quiet">More</button></> :
                <><button className="button button-primary" disabled={connectionDisabled(person.id)} onClick={() => requestConnection(person.id)}><UserPlus size={17} /> {connectionLabel(person.id)}</button><Link prefetch={false} className="button button-outline" href="/messages">Message</Link><button className="button button-quiet">More</button></>}
            </div>
            {connectionError && <div className="form-error" role="alert">{connectionError}</div>}
          </div>
        </section>
        {mine && <section className="surface profile-section analytics-section"><header><div><h2>Analytics</h2><span>Private to you</span></div></header><div><article><b>84 profile views</b><p>Discover who viewed your profile.</p></article><article><b>1,204 post impressions</b><p>See who&apos;s engaging with your posts.</p></article><article><b>39 search appearances</b><p>See how often you appear in search.</p></article></div></section>}
        <section className="surface profile-section"><header><div><h2>About</h2></div>{mine && <button className="icon-button" aria-label="Edit about" onClick={() => setProfileOpen(true)}><Pencil size={19} /></button>}</header><p>{person.about || "Add a summary about your experience and interests."}</p></section>
        <section className="surface profile-section">
          <header><div><h2>Experience</h2></div>{mine && <button className="icon-button" aria-label="Add experience" onClick={() => { setFormError(""); setExperienceOpen(true); }}><Plus size={20} /></button>}</header>
          {experienceRows.length ? experienceRows.map((experience) => <article className="experience-row" key={experience.id}><span className="company-logo">{experience.companyName.slice(0, 2).toUpperCase()}</span><div><h3>{experience.title}</h3><b>{experience.companyName}{experience.current ? " · Full-time" : ""}</b><span>{experience.startDate} - {experience.current ? "Present" : experience.endDate}</span><span>{experience.location}</span>{experience.description && <p>{experience.description}</p>}</div></article>) : <div className="profile-empty"><p>Add a role so people can understand your professional experience.</p>{mine && <button className="button button-outline" onClick={() => setExperienceOpen(true)}>Add experience</button>}</div>}
        </section>
        <section className="surface profile-section"><header><div><h2>Skills</h2></div>{mine && <button className="button button-outline">Demonstrate skills</button>}</header><div className="skill-row"><b>Product strategy</b><span><Building2 size={16} /> Northstar Systems</span><span>26 endorsements</span></div><div className="skill-row"><b>Interaction design</b><span><Building2 size={16} /> Northstar Systems and Pattern Digital</span><span>41 endorsements</span></div></section>
      </div>
      <aside className="profile-right"><section className="surface language-card"><div><b>Profile language</b>{mine && <Pencil size={17} />}</div><span>English</span><hr /><div><b>Public profile & URL</b>{mine && <Pencil size={17} />}</div><span>linkedin.local/in/{username}</span></section><section className="surface suggestions"><h2>People also viewed</h2>{suggestionPeople.map((item) => <article key={item.id}><Avatar name={item.name} src={item.avatar} /><div><b>{item.name}</b><span>{item.headline}</span><button className="button button-quiet" disabled={connectionDisabled(item.id)} onClick={() => requestConnection(item.id)}>{connectionLabel(item.id)}</button></div></article>)}</section></aside>

      {profileOpen && <div className="dialog-backdrop" role="presentation"><section className="surface profile-dialog" aria-label="Edit profile" role="dialog"><header><h2>Edit intro</h2><button className="icon-button" aria-label="Close" onClick={() => setProfileOpen(false)}><X size={20} /></button></header><label>Full name<input value={profileDraft.name} onChange={(event) => setProfileDraft({ ...profileDraft, name: event.target.value })} /></label><label>Headline<input value={profileDraft.headline} onChange={(event) => setProfileDraft({ ...profileDraft, headline: event.target.value })} /></label><label>Location<input value={profileDraft.location} onChange={(event) => setProfileDraft({ ...profileDraft, location: event.target.value })} /></label><label>About<textarea value={profileDraft.about} onChange={(event) => setProfileDraft({ ...profileDraft, about: event.target.value })} /></label>{formError && <div className="form-error" role="alert">{formError}</div>}<footer><button className="button button-quiet" onClick={() => setProfileOpen(false)}>Cancel</button><button className="button button-primary" disabled={saving} onClick={saveProfile}>{saving ? "Saving…" : "Save"}</button></footer></section></div>}
      {experienceOpen && <div className="dialog-backdrop" role="presentation"><section className="surface profile-dialog" aria-label="Add experience" role="dialog"><header><h2>Add experience</h2><button className="icon-button" aria-label="Close" onClick={() => setExperienceOpen(false)}><X size={20} /></button></header><label>Title<input value={experienceDraft.title} onChange={(event) => setExperienceDraft({ ...experienceDraft, title: event.target.value })} /></label><label>Company name<input value={experienceDraft.companyName} onChange={(event) => setExperienceDraft({ ...experienceDraft, companyName: event.target.value })} /></label><label>Location<input value={experienceDraft.location} onChange={(event) => setExperienceDraft({ ...experienceDraft, location: event.target.value })} /></label><label>Start month<input type="month" value={experienceDraft.startDate} onChange={(event) => setExperienceDraft({ ...experienceDraft, startDate: event.target.value })} /></label><label>Description<textarea value={experienceDraft.description} onChange={(event) => setExperienceDraft({ ...experienceDraft, description: event.target.value })} /></label>{formError && <div className="form-error" role="alert">{formError}</div>}<footer><button className="button button-quiet" onClick={() => setExperienceOpen(false)}>Cancel</button><button className="button button-primary" disabled={saving} onClick={addExperience}>{saving ? "Adding…" : "Add experience"}</button></footer></section></div>}
    </div>
  );
}