// PiCometixLine — pi-agent 状态栏扩展入口
// 移植自 CCometixLine：通过 ctx.ui.setFooter() 自定义 pi 的 footer 状态栏，
// 显示 Model | Directory | Git | Context Window | Cost | Tokens | Thinking 等段。

import type { ExtensionAPI, ExtensionCommandContext, ExtensionContext } from "@earendil-works/pi-coding-agent";
import { Container, SelectList, type SelectItem, Text } from "@earendil-works/pi-tui";
import { DynamicBorder } from "@earendil-works/pi-coding-agent";
import { loadConfig, saveConfig, initConfig } from "./config.ts";
import { getTheme, THEME_NAMES } from "./themes.ts";
import { renderFooterLine } from "./render.ts";
import { collectSegments, type CclineState, type FooterDataLike } from "./segments.ts";
import { GitCache } from "./git.ts";

/** footerData 的完整结构（对齐 pi 的 ReadonlyFooterDataProvider） */
interface FooterData {
  getGitBranch(): string | null;
  getExtensionStatuses(): ReadonlyMap<string, string>;
  getAvailableProviderCount(): number;
  onBranchChange(cb: () => void): () => void;
}

/** 主题描述（命令选择列表用） */
const THEME_DESC: Record<string, string> = {
  cometix: "NerdFont · 16色（默认）",
  default: "Plain emoji · 16色",
  minimal: "Plain · 低饱和",
  nord: "NerdFont · Nord 配色",
  gruvbox: "NerdFont · Gruvbox 配色",
  "powerline-dark": "Powerline · 深色",
  "powerline-light": "Powerline · 浅色",
  "powerline-rose-pine": "Powerline · Rose Pine",
  "powerline-tokyo-night": "Powerline · Tokyo Night",
};

/** 运行时状态 */
interface RuntimeState {
  config: ReturnType<typeof getTheme>;
  modelConfig: ReturnType<typeof loadConfig>["modelConfig"];
  state: CclineState;
  gitCache: GitCache;
  enabled: boolean;
  /** 由 footer factory 注入的重新渲染回调（事件中调用以刷新 footer） */
  requestRender?: () => void;
}

export default function (pi: ExtensionAPI) {
  const rt: RuntimeState = {
    config: getTheme("cometix"),
    modelConfig: { models: [], contextModifiers: [] },
    state: { model: undefined, thinkingLevel: undefined },
    gitCache: new GitCache(false),
    enabled: true,
  };

  /** 重新加载配置文件（config.json + models.json） */
  function reload() {
    const { config, modelConfig, enabled } = loadConfig();
    rt.config = config;
    rt.modelConfig = modelConfig;
    rt.enabled = enabled;
    const gitSeg = config.segments.find((s) => s.id === "git");
    rt.gitCache.setShowSha(Boolean(gitSeg?.options?.["show_sha"]));
  }

  /** Model<any> → 精简 state.model */
  function toModelState(m: {
    id: string;
    name: string;
    contextWindow: number;
    provider: string;
    reasoning: boolean;
  }) {
    return {
      id: m.id,
      name: m.name,
      contextWindow: m.contextWindow,
      provider: m.provider,
      reasoning: m.reasoning,
    };
  }

  /** 安装自定义 footer */
  function installFooter(ctx: ExtensionContext) {
    ctx.ui.setFooter((tui, _theme, footerData: FooterData) => {
      // 注入重新渲染回调，供事件触发 footer 刷新
      rt.requestRender = () => tui.requestRender();
      // git 分支变化 → 重新渲染
      const unsub = footerData.onBranchChange(() => rt.requestRender?.());
      return {
        dispose: unsub,
        invalidate() {},
        render(width: number): string[] {
          if (!rt.enabled) return [];
          // 触发异步 git 状态刷新（节流，不阻塞渲染），刷新后重新渲染
          rt.gitCache.refresh(ctx.cwd, () => rt.requestRender?.()).catch(() => {});
          // 兜底：state.model 未初始化时用闭包 ctx.model
          const model = rt.state.model ?? (ctx.model ? toModelState(ctx.model) : undefined);
          const thinking = rt.state.thinkingLevel ?? (ctx.thinkingLevel as string | undefined);
          const items = collectSegments(
            {
              ctx,
              footerData: footerData as FooterDataLike,
              gitCache: rt.gitCache,
              state: { model, thinkingLevel: thinking },
              modelConfig: rt.modelConfig,
            },
            rt.config,
          );
          return renderFooterLine(rt.config, items, width);
        },
      };
    });
  }

  /** 卸载自定义 footer，恢复 pi 默认 */
  function uninstallFooter(ctx: ExtensionContext) {
    ctx.ui.setFooter(undefined);
  }

  // ─── 会话生命周期 ────────────────────────────────────────────────────────

  pi.on("session_start", async (_event, ctx) => {
    reload();
    // 初始化运行时状态：当前 model + thinking level
    rt.state.model = ctx.model ? toModelState(ctx.model) : undefined;
    rt.state.thinkingLevel = ctx.thinkingLevel as string | undefined;
    if (rt.enabled) installFooter(ctx);
    // 首次强制刷新 git 状态
    rt.gitCache.refresh(ctx.cwd, () => rt.requestRender?.(), true).catch(() => {});
  });

  pi.on("model_select", async (event, _ctx) => {
    const m = event.model;
    rt.state.model = m ? toModelState(m) : undefined;
    rt.requestRender?.();
  });

  pi.on("thinking_level_select", async (event, _ctx) => {
    rt.state.thinkingLevel = event.level as string;
    rt.requestRender?.();
  });

  pi.on("session_info_changed", async (_event, _ctx) => {
    // 会话名变化 → session 段刷新
    rt.requestRender?.();
  });

  pi.on("turn_end", async (_event, ctx) => {
    // 每轮结束强制刷新 git 状态（status/ahead/behind 可能变化）
    rt.gitCache.refresh(ctx.cwd, () => rt.requestRender?.(), true).catch(() => {});
    // token/cost 由 pi 自动重绘 footer，此处不重复 requestRender
  });

  // ─── 命令：/ccline ─────────────────────────────────────────────────────────

  pi.registerCommand("ccline", {
    description: "PiCometixLine 状态栏：主题选择 / 开关 / 初始化",
    handler: async (args, ctx) => {
      const parts = args.trim().split(/\s+/).filter(Boolean);
      const sub = parts[0]?.toLowerCase();

      if (sub === "off") {
        rt.enabled = false;
        uninstallFooter(ctx);
        saveConfig(rt.config, false);
        ctx.ui.notify("PiCometixLine 已关闭（恢复默认 footer）", "info");
        return;
      }
      if (sub === "on") {
        rt.enabled = true;
        reload();
        installFooter(ctx);
        saveConfig(rt.config, true);
        ctx.ui.notify("PiCometixLine 已开启", "info");
        return;
      }
      if (sub === "init") {
        initConfig();
        reload();
        ctx.ui.notify("已初始化配置：~/.pi/agent/ccline/", "info");
        return;
      }
      if (sub === "theme") {
        const name = parts[1];
        if (name && THEME_NAMES.includes(name as (typeof THEME_NAMES)[number])) {
          rt.config = getTheme(name);
          saveConfig(rt.config, rt.enabled);
          reload();
          rt.requestRender?.();
          ctx.ui.notify(`已切换主题：${name}`, "info");
        } else {
          ctx.ui.notify(`未知主题。可用：${THEME_NAMES.join(", ")}`, "warning");
        }
        return;
      }
      if (sub === "status") {
        ctx.ui.notify(
          `ccline: ${rt.enabled ? "on" : "off"} | theme=${rt.config.theme} | model=${rt.state.model?.name ?? "-"}`,
          "info",
        );
        return;
      }

      // 默认：打开主题选择对话框
      await pickTheme(ctx);
    },
  });

  /** 主题选择对话框 */
  async function pickTheme(ctx: ExtensionCommandContext) {
    const items: SelectItem[] = THEME_NAMES.map((n) => ({
      value: n,
      label: n,
      description: n === rt.config.theme ? `${THEME_DESC[n] ?? ""} ·（当前）` : (THEME_DESC[n] ?? ""),
    }));

    const result = await ctx.ui.custom<string | null>((tui, theme, _kb, done) => {
      const container = new Container();
      container.addChild(new DynamicBorder((s: string) => theme.fg("accent", s)));
      container.addChild(new Text(theme.fg("accent", theme.bold("PiCometixLine 主题")), 1, 0));
      container.addChild(new Text(theme.fg("muted", "为 pi-agent footer 选择状态栏主题"), 1, 0));

      const list = new SelectList(items, Math.min(items.length, 12), {
        selectedPrefix: (t) => theme.fg("accent", t),
        selectedText: (t) => theme.fg("accent", t),
        description: (t) => theme.fg("muted", t),
        scrollInfo: (t) => theme.fg("dim", t),
        noMatch: (t) => theme.fg("warning", t),
      });
      list.onSelect = (item) => done(item.value);
      list.onCancel = () => done(null);
      container.addChild(list);

      container.addChild(new Text(theme.fg("dim", "↑↓ 选择 • enter 确认 • esc 取消"), 1, 0));
      container.addChild(new DynamicBorder((s: string) => theme.fg("accent", s)));

      return {
        render: (w: number) => container.render(w),
        invalidate: () => container.invalidate(),
        handleInput: (data: string) => {
          list.handleInput(data);
          tui.requestRender();
        },
      };
    });

    if (result) {
      rt.config = getTheme(result);
      saveConfig(rt.config, rt.enabled);
      reload();
      rt.requestRender?.();
      ctx.ui.notify(`已切换主题：${result}`, "info");
    }
  }
}