"use client";

import { useMemo, useState } from "react";

import type { FinalApprovalChecklistResponse } from "@pipeline/shared";

import {
  ApiError,
  fetchFinalApprovalChecklist,
  submitFinalApproval,
  submitFinalRevisionRequest,
} from "@/shared/pipeline-api";
import { buildFinalApprovalViewModel } from "./model";

type FinalApprovalPanelProps = {
  articleId: string;
};

const DEFAULT_FRONTMATTER = '{\n  "category": "Guides"\n}';

export function FinalApprovalPanel({ articleId }: FinalApprovalPanelProps) {
  const [checklist, setChecklist] = useState<FinalApprovalChecklistResponse | null>(null);
  const [draftVersionInput, setDraftVersionInput] = useState("");
  const [contentPath, setContentPath] = useState("/guides/final-approval-gate");
  const [author, setAuthor] = useState("Editorial Team");
  const [publishingMode, setPublishingMode] = useState("MANUAL");
  const [frontmatterText, setFrontmatterText] = useState(DEFAULT_FRONTMATTER);
  const [revisionReason, setRevisionReason] = useState("Need final refinements before approval.");
  const [busyKey, setBusyKey] = useState<string | null>(null);
  const [message, setMessage] = useState("");

  const viewModel = useMemo(
    () => buildFinalApprovalViewModel(checklist),
    [checklist],
  );

  async function refreshChecklist() {
    setBusyKey("refresh");
    setMessage("");
    try {
      const response = await fetchFinalApprovalChecklist(articleId);
      setChecklist(response);
      if (!draftVersionInput && response.draft_version) {
        setDraftVersionInput(String(response.draft_version));
      }
    } catch (error) {
      setMessage(error instanceof ApiError ? error.message : "Failed to fetch final checklist.");
    } finally {
      setBusyKey(null);
    }
  }

  async function approve() {
    let frontmatter: Record<string, unknown> | null = null;
    try {
      const parsed = JSON.parse(frontmatterText);
      if (parsed && typeof parsed === "object" && !Array.isArray(parsed)) {
        frontmatter = parsed as Record<string, unknown>;
      }
    } catch {
      setMessage("Frontmatter must be a valid JSON object.");
      return;
    }

    const parsedDraftVersion = Number.parseInt(draftVersionInput, 10);
    setBusyKey("approve");
    setMessage("");
    try {
      const response = await submitFinalApproval(articleId, {
        draft_version: Number.isNaN(parsedDraftVersion) ? null : parsedDraftVersion,
        publishing_settings: {
          content_path: contentPath,
          author,
          publishing_mode: publishingMode,
          frontmatter,
        },
      });
      setChecklist(response.checklist);
      setMessage(`Final approval completed. Article status: ${response.article.status}.`);
    } catch (error) {
      setMessage(error instanceof ApiError ? error.message : "Final approval failed.");
      await refreshChecklist();
    } finally {
      setBusyKey(null);
    }
  }

  async function requestRevision() {
    const parsedDraftVersion = Number.parseInt(draftVersionInput, 10);
    setBusyKey("revision");
    setMessage("");
    try {
      const response = await submitFinalRevisionRequest(articleId, {
        reason: revisionReason,
        draft_version: Number.isNaN(parsedDraftVersion) ? null : parsedDraftVersion,
      });
      setChecklist(response.checklist);
      setMessage(`Revision requested. Article status: ${response.article.status}.`);
    } catch (error) {
      setMessage(error instanceof ApiError ? error.message : "Failed to request revision.");
    } finally {
      setBusyKey(null);
    }
  }

  return (
    <section className="reviewPanel">
      <div className="sectionHeader">
        <div>
          <h2>Final approval gate</h2>
          <p>Checklist blockers: {viewModel.blockers.length}</p>
        </div>
        <div className="formActions">
          <button type="button" onClick={() => void refreshChecklist()} disabled={busyKey !== null}>
            {busyKey === "refresh" ? "Refreshing..." : "Refresh checklist"}
          </button>
        </div>
      </div>

      {message ? <p className={message.includes("failed") ? "formError" : "formSuccess"}>{message}</p> : null}

      {viewModel.items.length > 0 ? (
        <table className="table">
          <thead>
            <tr>
              <th>Checklist item</th>
              <th>Status</th>
              <th>Details</th>
            </tr>
          </thead>
          <tbody>
            {viewModel.items.map((item) => (
              <tr key={item.key}>
                <td>{item.title}</td>
                <td>{item.completed ? "Completed" : "Blocked"}</td>
                <td>{item.completed ? "—" : item.blocker || "—"}</td>
              </tr>
            ))}
          </tbody>
        </table>
      ) : (
        <p>No checklist yet. Refresh to load current gate status.</p>
      )}

      {viewModel.completedItems.length > 0 ? (
        <ul className="timeline">
          {viewModel.completedItems.map((item) => (
            <li key={item}>Completed: {item}</li>
          ))}
        </ul>
      ) : null}

      {viewModel.blockers.length > 0 ? (
        <ul className="timeline">
          {viewModel.blockers.map((item) => (
            <li key={item}>{item}</li>
          ))}
        </ul>
      ) : null}

      <div className="reviewActions">
        <input
          value={draftVersionInput}
          onChange={(event) => setDraftVersionInput(event.target.value)}
          placeholder={viewModel.draftVersion ? String(viewModel.draftVersion) : "Draft version"}
          inputMode="numeric"
        />
        <input
          value={contentPath}
          onChange={(event) => setContentPath(event.target.value)}
          placeholder="/guides/final-approval-gate"
        />
        <input
          value={author}
          onChange={(event) => setAuthor(event.target.value)}
          placeholder="Author"
        />
        <input
          value={publishingMode}
          onChange={(event) => setPublishingMode(event.target.value)}
          placeholder="MANUAL"
        />
        <textarea
          value={frontmatterText}
          onChange={(event) => setFrontmatterText(event.target.value)}
          rows={4}
        />
        <button type="button" onClick={() => void approve()} disabled={busyKey !== null}>
          {busyKey === "approve" ? "Approving..." : "Approve final"}
        </button>
      </div>

      <div className="reviewActions">
        <input
          value={revisionReason}
          onChange={(event) => setRevisionReason(event.target.value)}
          placeholder="Revision reason"
        />
        <button type="button" onClick={() => void requestRevision()} disabled={busyKey !== null}>
          {busyKey === "revision" ? "Submitting..." : "Request revision"}
        </button>
      </div>
    </section>
  );
}