/**
 * The app in a terminal. The forge runs this on a pty when someone
 * `ssh`es to the app, over the same data as the page and through the same
 * actions, as the account at the keyboard. j/k move, a adds, d removes the
 * note under the cursor, q leaves. Plain ANSI, no dependencies.
 */

import {
  addNote,
  canDelete,
  deleteNote,
  listNotes,
  type Note,
} from "./actions.ts";
import { openDb } from "./db.ts";
import { ssh, title, where } from "./env.ts";
import { whoAtTty } from "./who.ts";

const db = openDb();
const me = whoAtTty();
const esc = "\x1b[";
const dim = (s: string): string => `${esc}2m${s}${esc}0m`;
const bold = (s: string): string => `${esc}1m${s}${esc}0m`;
const out = (s: string): void => {
  process.stdout.write(s);
};

let cursor = 0;
let typing: string | undefined;
let said = "";

const notes = (): Note[] => {
  const listed = listNotes(db, me);
  return listed.ok ? listed.value : [];
};

function draw(): void {
  const rows = notes();
  const lines = [
    `${bold(title)}  ${dim(where)}  ${dim(me.role === "anon" ? "guest" : `${me.name}${me.role === "admin" ? " (admin)" : ""}`)}`,
    ssh === undefined ? "" : dim(`connect: ${ssh}`),
    "",
  ];
  if (rows.length === 0)
    lines.push(
      dim(
        me.role === "anon"
          ? "No notes yet."
          : "No notes yet. Press a to add one.",
      ),
    );
  rows.forEach((note, i) => {
    const body = i === cursor ? bold(note.body) : note.body;
    lines.push(
      `${i === cursor ? "▸" : " "} ${body}  ${dim(`${note.author_name} · ${note.created_at.slice(0, 16).replace("T", " ")}`)}`,
    );
  });
  lines.push("");
  if (typing !== undefined) lines.push(`New note: ${typing}${esc}7m ${esc}0m`);
  else if (said !== "") lines.push(said);
  else
    lines.push(
      dim(
        me.role === "anon"
          ? "j/k move · q quit · sign in with a key the forge knows to add"
          : "j/k move · a add · d delete · q quit",
      ),
    );
  out(`${esc}2J${esc}H${lines.join("\r\n")}`);
}

process.stdin.setRawMode?.(true);
process.stdin.resume();
process.stdin.setEncoding("utf8");
draw();
process.stdin.on("data", (key: string) => {
  said = "";
  if (typing !== undefined) {
    if (key === "\r") {
      const added = addNote(db, me, { body: typing });
      if (!added.ok) said = added.message;
      typing = undefined;
      cursor = 0;
    } else if (key === "\x1b") typing = undefined;
    else if (key === "\x7f") typing = typing.slice(0, -1);
    else if (key >= " ") typing += key;
    draw();
    return;
  }
  if (key === "q" || key === "\x03") {
    out(`${esc}2J${esc}H`);
    process.exit(0);
  }
  const rows = notes();
  if (key === "j" || key === "\x1b[B")
    cursor = Math.min(cursor + 1, Math.max(0, rows.length - 1));
  if (key === "k" || key === "\x1b[A") cursor = Math.max(cursor - 1, 0);
  if (key === "a") {
    if (me.role === "anon") said = "Sign in to add a note.";
    else typing = "";
  }
  if (key === "d") {
    const note = rows[cursor];
    if (note === undefined) said = "Nothing to remove.";
    else if (!canDelete(me, note))
      said = "Only the author or an admin can remove a note.";
    else {
      const removed = deleteNote(db, me, { id: note.id });
      if (!removed.ok) said = removed.message;
      cursor = Math.min(cursor, Math.max(0, rows.length - 2));
    }
  }
  draw();
});
process.stdout.on("resize", draw);