/**
 * VariableView — flat list of all variable key-value pairs.
 *
 * Hovering a value shows a popup with:
 *   - Declaration expression (if any), styled distinctly
 *   - Active tag modifiers: #tag +N (from $source)
 */

import { Component, For, createMemo, Show, createSignal } from "solid-js";
import { useJournalStream } from "../stores/journalStream";
import { useJournalCompletions } from "./completions";
import { getMods, getDeclExpr } from "./var-reactivity";

export const VariableView: Component = () => {
  const stream = useJournalStream();
  const comp = useJournalCompletions();

  const values = createMemo(() => stream.variables);

  /** Runtime engine diagnostics (bad declarations / modifiers). */
  const diagnostics = createMemo(() => comp.diagnostics());

  /** Flat list of all variables */
  const items = createMemo(() => {
    const vars = values();
    return Object.entries(vars).map(([key, value]) => ({
      key,
      value,
      isTag: value.startsWith("#"),
    }));
  });

  const hasAnyData = () =>
    comp.data.declarations.length > 0 || Object.keys(values()).length > 0;

  return (
    <div class="h-full overflow-y-auto bg-gray-50">
      <Show when={diagnostics().length > 0}>
        <div class="border-b border-amber-200 bg-amber-50 px-3 py-2">
          <div class="text-xs font-semibold text-amber-800 mb-1">
            变量求值有 {diagnostics().length} 个问题
          </div>
          <ul class="space-y-1">
            <For each={diagnostics()}>
              {(d) => (
                <li class="text-xs text-amber-700 font-mono break-all">{d.message}</li>
              )}
            </For>
          </ul>
        </div>
      </Show>
      <Show
        when={hasAnyData()}
        fallback={
          <p class="text-center text-gray-400 text-xs py-8">
            暂无变量定义。在文档中使用 ```yaml role=declare 代码块定义变量。
          </p>
        }
      >
        <div class="divide-y divide-gray-100">
          <For each={items()}>
            {(item) => (
              <VariableRow
                key={item.key}
                value={item.value}
                isTag={item.isTag}
              />
            )}
          </For>
        </div>
      </Show>
    </div>
  );
};

// ---------------------------------------------------------------------------
// VariableRow — single row with hover popup
// ---------------------------------------------------------------------------

const VariableRow: Component<{
  key: string;
  value: string;
  isTag: boolean;
}> = (props) => {
  const [hovered, setHovered] = createSignal(false);

  const declExpr = createMemo(() => getDeclExpr(props.key));
  const mods = createMemo(() => getMods(props.key));

  const hasPopup = () => !!declExpr() || mods().length > 0;

  return (
    <div
      class="relative flex items-center px-3 py-1.5 hover:bg-white/50 transition-colors"
      onMouseEnter={() => setHovered(true)}
      onMouseLeave={() => setHovered(false)}
    >
      <span class="flex-1 text-sm font-mono text-gray-800">{props.key}</span>
      <span
        class={props.isTag
          ? "text-sm font-mono text-purple-700 font-semibold"
          : "text-sm font-mono text-gray-700 font-semibold"
        }
      >
        {props.value}
      </span>

      {/* Hover popup */}
      <Show when={hasPopup() && hovered()}>
        <div class="absolute right-0 top-full mt-1 z-50 bg-white border border-gray-200 rounded-md shadow-lg p-2 min-w-45 text-xs">
          {/* Declaration expression */}
          <Show when={declExpr()}>
            <div class="mb-1">
              <span class="text-gray-400">expr: </span>
              <span class="font-mono text-gray-500 bg-gray-50 px-1 rounded">
                {declExpr()}
              </span>
            </div>
          </Show>

          {/* Tag modifiers */}
          <Show when={mods().length > 0}>
            <div class={declExpr() ? "border-t border-gray-100 pt-1 mt-1" : ""}>
              <For each={mods()}>
                {(mod) => (
                  <div class="flex items-center gap-1 text-gray-500">
                    <span class="font-mono text-purple-600">{mod.tag}</span>
                    <span>+{mod.value}</span>
                    <span class="text-gray-400">(from {mod.source})</span>
                  </div>
                )}
              </For>
            </div>
          </Show>
        </div>
      </Show>
    </div>
  );
};

export default VariableView;