"use client";

import { useMemo, useState } from "react";
import Link from "next/link";
import { Bookmark, BriefcaseBusiness, CheckCircle2, MapPin, Search, SlidersHorizontal } from "lucide-react";
import { jobs } from "@/lib/demo-data";

export function JobsView({ selectedId }: { selectedId?: string }) {
  const [query, setQuery] = useState("");
  const [location, setLocation] = useState("");
  const [saved, setSaved] = useState<string[]>([]);
  const [applied, setApplied] = useState<string[]>([]);
  const [openFilter, setOpenFilter] = useState<string | null>(null);
  const [applicationError, setApplicationError] = useState("");
  const [jobActionError, setJobActionError] = useState("");
  const [applicationJobId, setApplicationJobId] = useState<string | null>(null);
  const [coverNote, setCoverNote] = useState("");
  const [resumeUrl, setResumeUrl] = useState("");
  const [submittingApplication, setSubmittingApplication] = useState(false);
  const [savingJobId, setSavingJobId] = useState<string | null>(null);
  const filtered = useMemo(() => jobs.filter((job) =>
    `${job.title} ${job.company.name}`.toLowerCase().includes(query.toLowerCase()) &&
    job.location.toLowerCase().includes(location.toLowerCase())
  ), [query, location]);
  const selected = jobs.find((job) => job.id === selectedId) ?? filtered[0] ?? jobs[0];
  const applicationJob = jobs.find((job) => job.id === applicationJobId) ?? null;

  function openApplication(jobId: string) {
    setApplicationError("");
    const job = jobs.find((item) => item.id === jobId);
    setCoverNote(job ? `I’m interested in the ${job.title} role at ${job.company.name}.` : "");
    setResumeUrl("");
    setApplicationJobId(jobId);
  }

  async function submitApplication(event: React.FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (!applicationJob) return;
    setApplicationError("");
    setSubmittingApplication(true);
    try {
      const payload = {
        action: "apply",
        jobId: applicationJob.id,
        coverNote: coverNote.trim(),
        ...(resumeUrl.trim() ? { resumeUrl: resumeUrl.trim() } : {}),
      };
      const response = await fetch("/api/jobs", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify(payload) });
      const result = await response.json().catch(() => ({})) as { error?: string };
      if (!response.ok) throw new Error(result.error ?? "Unable to submit this application.");
      setApplied((items) => items.includes(applicationJob.id) ? items : [...items, applicationJob.id]);
      setApplicationJobId(null);
    } catch (caught) {
      setApplicationError(caught instanceof Error ? caught.message : "Unable to submit this application.");
    } finally {
      setSubmittingApplication(false);
    }
  }

  async function saveJob(jobId: string) {
    if (saved.includes(jobId) || savingJobId) return;
    setSavingJobId(jobId);
    setJobActionError("");
    try {
      const response = await fetch("/api/jobs", { method: "POST", headers: { "content-type": "application/json" }, body: JSON.stringify({ action: "save", jobId }) });
      const result = await response.json().catch(() => ({})) as { savedJob?: { jobId?: string }, error?: string };
      if (!response.ok || result.savedJob?.jobId !== jobId) throw new Error(result.error ?? "Unable to save this job.");
      setSaved((items) => items.includes(jobId) ? items : [...items, jobId]);
    } catch (caught) {
      setJobActionError(caught instanceof Error ? caught.message : "Unable to save this job.");
    } finally {
      setSavingJobId(null);
    }
  }

  function saveLabel(jobId: string) {
    if (savingJobId === jobId) return "Saving…";
    return saved.includes(jobId) ? "Saved" : "Save";
  }

  return (
    <div className="jobs-page">
      <section className="job-search-bar">
        <label><Search size={19} /><input value={query} onChange={(event) => setQuery(event.target.value)} placeholder="Title, skill, or company" /></label>
        <label><MapPin size={19} /><input value={location} onChange={(event) => setLocation(event.target.value)} placeholder="City, state, or remote" /></label>
        <button className="button button-primary">Search</button>
      </section>
      <div className="filter-row">
        <button className="button button-outline" onClick={() => setOpenFilter(openFilter === "All filters" ? null : "All filters")}><SlidersHorizontal size={17} /> All filters</button>
        {["Date posted", "Experience level", "Company", "Remote"].map((filter) => (
          <span className="job-filter-wrap" key={filter}>
            <button className={`filter-pill ${openFilter === filter ? "active" : ""}`} onClick={() => setOpenFilter(openFilter === filter ? null : filter)}>{filter}</button>
            {openFilter === filter && (
              <div className="job-filter-menu">
                <button>Past 24 hours</button><button>Past week</button><button>Entry level</button><button>Mid-Senior level</button><button>Northstar Systems</button>
              </div>
            )}
          </span>
        ))}
        {openFilter === "All filters" && <div className="job-filter-menu all"><b>All filters</b><button>Easy Apply</button><button>Remote</button><button>Under 10 applicants</button><button>In your network</button></div>}
      </div>
      <div className="jobs-layout">
        <section className="surface job-results">
          <header><div><h1>Top job picks for you</h1><p>{filtered.length} results based on your profile</p></div></header>
          {filtered.length ? filtered.map((job) => (
            <Link prefetch={false} className={`job-listing ${selected.id === job.id ? "selected" : ""}`} href={`/jobs/${job.id}`} key={job.id}>
              <span className="company-logo">{job.company.logo}</span>
              <div><h2>{job.title}</h2><b>{job.company.name}</b><span>{job.location}</span><small>{job.salary} · {job.age}</small>{job.easyApply && <em>Easy Apply</em>}</div>
              <button className="icon-button" aria-label={`${saveLabel(job.id)} job`} disabled={savingJobId === job.id || saved.includes(job.id)} onClick={(event) => { event.preventDefault(); void saveJob(job.id); }}><Bookmark size={19} fill={saved.includes(job.id) ? "currentColor" : "none"} /></button>
            </Link>
          )) : <div className="empty-state"><Search size={34} /><h3>No jobs match those filters</h3><p>Try a broader title or remove the location.</p></div>}
        </section>
        <article className="surface job-detail">
          <div className="job-detail-company"><span className="company-logo company-logo-lg">{selected.company.logo}</span><Link prefetch={false} href={`/companies/${selected.company.slug}`}>{selected.company.name}</Link></div>
          <h1>{selected.title}</h1>
          <p>{selected.location} · {selected.age} · 38 applicants</p>
          <div className="job-tags"><span><BriefcaseBusiness size={17} /> {selected.type}</span><span>{selected.salary}</span></div>
          <div className="job-cta">
            <button className="button button-primary" disabled={applied.includes(selected.id)} onClick={() => openApplication(selected.id)}>
              {applied.includes(selected.id) ? <><CheckCircle2 size={18} /> Applied</> : "Easy Apply"}
            </button>
            <button className="button button-outline" disabled={savingJobId === selected.id || saved.includes(selected.id)} onClick={() => { void saveJob(selected.id); }}><Bookmark size={18} fill={saved.includes(selected.id) ? "currentColor" : "none"} /> {saveLabel(selected.id)}</button>
          </div>
          {jobActionError && <div className="form-error" role="alert">{jobActionError}</div>}
          {applicationError && <div className="form-error" role="alert">{applicationError}</div>}
          <hr />
          <h2>About the job</h2>
          <p>Join a collaborative product group building dependable tools for teams that run critical operations. You will lead end-to-end product work, partner closely with engineering and research, and raise the quality of our shared design practice.</p>
          <h3>What you’ll do</h3>
          <ul><li>Frame complex customer problems and turn them into clear product direction.</li><li>Prototype, test, and ship polished experiences with cross-functional partners.</li><li>Strengthen the systems and rituals that help the team do its best work.</li></ul>
          <h3>What we’re looking for</h3>
          <p>Strong product judgment, excellent communication, and a portfolio showing thoughtful decisions across complex workflows.</p>
        </article>
      </div>
      {applicationJob && (
        <div className="application-modal-backdrop" role="presentation">
          <section className="application-modal" role="dialog" aria-labelledby="application-title" aria-modal="true">
            <header>
              <span className="company-logo">{applicationJob.company.logo}</span>
              <div>
                <h2 id="application-title">Apply to {applicationJob.title}</h2>
                <p>{applicationJob.company.name} · {applicationJob.location}</p>
              </div>
            </header>
            <form onSubmit={submitApplication}>
              <label>
                Cover note
                <textarea value={coverNote} onChange={(event) => setCoverNote(event.target.value)} maxLength={2000} required />
              </label>
              <label>
                Resume URL <span>Optional</span>
                <input value={resumeUrl} onChange={(event) => setResumeUrl(event.target.value)} placeholder="https://example.com/resume.pdf" type="url" />
              </label>
              {applicationError && <div className="form-error" role="alert">{applicationError}</div>}
              <div className="application-modal-actions">
                <button className="button button-quiet" type="button" onClick={() => setApplicationJobId(null)}>Cancel</button>
                <button className="button button-primary" disabled={submittingApplication} type="submit">
                  {submittingApplication ? "Submitting…" : "Submit application"}
                </button>
              </div>
            </form>
          </section>
        </div>
      )}
    </div>
  );
}