// Helpers with no VS Code in them, so they can be tested with node:test.

/** Server-sent events: feed chunks, get back each event's data. */

export class SseParser {

  private buf = "";

  private data: string[] = [];

  push(chunk: string): string[] {

    this.buf += chunk;

    const out: string[] = [];

    let i: number;

    while ((i = this.buf.indexOf("\n")) >= 0) {

      const line = this.buf.slice(0, i).replace(/\r$/, "");

      this.buf = this.buf.slice(i + 1);

      if (line === "") {

        if (this.data.length) out.push(this.data.join("\n"));

        this.data = [];

      } else if (line.startsWith("data:")) {

        this.data.push(line.slice(5).replace(/^ /, ""));

      }

    }

    return out;

  }

}

export const KINDS: { kind: string; label: string; prefix: string }[] = [

  { kind: "claude-code", label: "Claude Code", prefix: "claude" },

  { kind: "antigravity", label: "Antigravity", prefix: "agy" },

  { kind: "kimi-code", label: "Kimi Code", prefix: "kimi" },

  { kind: "codex", label: "Codex", prefix: "codex" },

  { kind: "other", label: "Another MCP client", prefix: "agent" },

];

/** A name Spectra accepts: lower-case letters, digits and dashes. */

export function validName(n: string): boolean {

  return /^[a-z0-9][a-z0-9-]{0,63}$/.test(n);

}

/** A project name from a folder name. */

export function nameFromFolder(folder: string): string {

  const base = folder.replace(/[\\/]+$/, "").split(/[\\/]/).pop() ?? "";

  const n = base.toLowerCase().replace(/[^a-z0-9-]/g, "-").replace(/^-+/, "").slice(0, 64);

  return n || "project";

}

/** The suggested agent name for a kind on a project, not already taken. */

export function suggestAgentName(kind: string, project: string, taken: string[]): string {

  const prefix = KINDS.find((k) => k.kind === kind)?.prefix ?? "agent";

  const base = `${prefix}-${project}`.slice(0, 60);

  if (!taken.includes(base)) return base;

  for (let i = 2; ; i++) if (!taken.includes(`${base}-${i}`)) return `${base}-${i}`;

}

export const EXPIRIES: { label: string; arg: string | undefined }[] = [

  { label: "8 hours", arg: "8h" },

  { label: "A day", arg: "1d" },

  { label: "A week", arg: "7d" },

  { label: "Until I disable it", arg: undefined },

];

/** `~/x` with the home directory. */

export function expandHome(p: string, home: string): string {

  return p === "~" ? home : p.startsWith("~/") ? home.replace(/\/$/, "") + p.slice(1) : p;

}

/** The arguments of the stdio shim for an agent. */

export function shimArgs(agent: string, home: string): string[] {

  return ["mcp", "--agent", agent, "--home", home];

}

/** Antigravity's mcp_config.json with Spectra's server set, keeping the rest. */

export function mergeMcpConfig(existing: string, command: string, args: string[]): string {

  let cfg: Record<string, unknown> = {};

  if (existing.trim()) {

    const parsed = JSON.parse(existing);

    if (parsed && typeof parsed === "object" && !Array.isArray(parsed)) cfg = parsed as Record<string, unknown>;

  }

  const servers = (cfg.mcpServers && typeof cfg.mcpServers === "object" ? cfg.mcpServers : {}) as Record<string, unknown>;

  servers.spectra = { command, args };

  cfg.mcpServers = servers;

  return JSON.stringify(cfg, null, 2) + "\n";

}

/** The project whose folder holds `folder`, the deepest if several do. */

export function projectForFolder(projects: { name: string; path?: string | null }[], folder: string): string | undefined {

  const norm = (p: string) => p.replace(/[\\/]+$/, "");

  const f = norm(folder);

  let best: { name: string; len: number } | undefined;

  for (const p of projects) {

    if (!p.path) continue;

    const q = norm(p.path);

    if ((f === q || f.startsWith(q + "/")) && (!best || q.length > best.len)) best = { name: p.name, len: q.length };

  }

  return best?.name;

}

/** `12:04` today, else `3 Nov 12:04`. */

export function when(ms: number, now = Date.now()): string {

  const d = new Date(ms);

  const t = d.toTimeString().slice(0, 5);

  return new Date(now).toDateString() === d.toDateString() ? t : `${d.getDate()} ${d.toLocaleString("en-GB", { month: "short" })} ${t}`;

}

/** Text for HTML. */

export function esc(s: string): string {

  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;").replace(/'/g, "&#39;");

}