/**
 * agent-list.ts — Rich agent list with source grouping and override indicators.
 *
 * Displays agents grouped by source (built-in, project, personal)
 * with model resolution, source indicators, and disabled state markers.
 */
import type { ExtensionCommandContext } from "@mariozechner/pi-coding-agent";
import { getAgentConfig, getAllTypes } from "../agent-types.js";
import { getModelLabel } from "../model-resolver.js";

/**
 * Show the rich agent list grouped by source.
 * User selects an agent → calls the detail callback.
 *
 * @param ctx        Extension command context
 * @param onSelect   Callback when user selects an agent (receives name)
 */
export async function showAgentList(
  ctx: ExtensionCommandContext,
  onSelect: (name: string) => Promise<void>,
): Promise<void> {
  const allNames = getAllTypes();
  if (allNames.length === 0) {
    ctx.ui.notify("No agents found.", "info");
    return;
  }

  // Categorize agents by source
  const builtins: string[] = [];
  const project: string[] = [];
  const personal: string[] = [];
  const disabled: string[] = [];

  for (const name of allNames) {
    const cfg = getAgentConfig(name);
    if (!cfg) continue;
    const isDisabled = cfg.enabled === false;

    if (isDisabled) {
      disabled.push(name);
    } else if (cfg.source === "project") {
      project.push(name);
    } else if (cfg.source === "global") {
      personal.push(name);
    } else {
      builtins.push(name);
    }
  }

  // Build grouped options
  const options: string[] = [];
  const nameMap = new Map<string, string>(); // display label → agent name

  const addGroup = (label: string, names: string[], indicator: string) => {
    if (names.length === 0) return;
    options.push(`─── ${label} ───`);
    for (const name of names.sort()) {
      const cfg = getAgentConfig(name);
      const model = getModelLabel(cfg?.model ?? "inherit");
      const display = `${indicator} ${name} · ${model}`;
      options.push(`  ${display}`);
      nameMap.set(`  ${display}`, name);
    }
  };

  addGroup("Built-in", builtins, "");
  addGroup("Project (.pi/agents/)", project, "•");
  addGroup("Personal (~/.pi/agent/agents/)", personal, "◦");

  // Disabled group at the end
  if (disabled.length > 0) {
    options.push("─── Disabled ───");
    for (const name of disabled.sort()) {
      options.push(`  ✕ ${name} (disabled)`);
      nameMap.set(`  ✕ ${name} (disabled)`, name);
    }
  }

  const choice = await ctx.ui.select("Agent types", options);
  if (!choice) return;

  const agentName = nameMap.get(choice);
  if (agentName) {
    await onSelect(agentName);
  }
}