import { Brain, RotateCcw, Save } from "lucide-react";
import React, { useEffect, useState } from "react";
import { Button } from "../../../ui/button";
import { SettingCard, SettingsSection } from "../../settings-ui";
import {
  DEFAULT_PHASE1_SYSTEM,
  DEFAULT_PHASE2_SYSTEM,
} from "../../../../infrastructure/ai/rcaAgent/rcaRunner";

const STORAGE_KEY = "netcatty_rca_prompts_v1";

interface RcaPromptsConfig {
  phase1?: string;
  phase2?: string;
}

function loadConfig(): RcaPromptsConfig {
  try {
    const raw = localStorage.getItem(STORAGE_KEY);
    if (raw) return JSON.parse(raw);
  } catch (_) {}
  return {};
}

function saveConfig(cfg: RcaPromptsConfig) {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(cfg));
}

export const RcaPromptSettings: React.FC = () => {
  const defaults = {
    phase1: DEFAULT_PHASE1_SYSTEM,
    phase2: DEFAULT_PHASE2_SYSTEM,
  };

  const [phase1, setPhase1] = useState("");
  const [phase2, setPhase2] = useState("");
  const [savedVersion, setSavedVersion] = useState<{ p1: string; p2: string }>({ p1: "", p2: "" });

  // 加载 localStorage 中的自定义值（无则空字符串，表示"使用默认"）
  useEffect(() => {
    const cfg = loadConfig();
    const p1 = cfg.phase1 ?? "";
    const p2 = cfg.phase2 ?? "";
    setPhase1(p1);
    setPhase2(p2);
    setSavedVersion({ p1, p2 });
  }, []);

  const dirty = phase1 !== savedVersion.p1 || phase2 !== savedVersion.p2;
  const phase1IsDefault = !phase1.trim();
  const phase2IsDefault = !phase2.trim();

  const handleSave = () => {
    const cfg: RcaPromptsConfig = {
      phase1: phase1.trim() ? phase1 : undefined,
      phase2: phase2.trim() ? phase2 : undefined,
    };
    saveConfig(cfg);
    setSavedVersion({ p1: phase1, p2: phase2 });
  };

  const handleResetAll = () => {
    setPhase1("");
    setPhase2("");
  };

  return (
    <SettingsSection
      anchorId="ai-rca-prompts"
      title="RCA 智能诊断提示词"
    >
      <p className="text-sm text-muted-foreground mb-4">
        自定义 AI 根因分析（RCA）的系统提示词。留空表示使用内置默认值。
        Phase 1 是诊断命令规划，Phase 2 是根因综合分析。
      </p>
      <SettingCard divided={false}>
        <div className="flex items-center justify-between gap-3 mb-4">
          <div className="flex items-center gap-2 text-sm text-muted-foreground">
            <Brain size={16} />
            <span>自定义提示词会覆盖内置默认值，点击"恢复默认"可清空编辑内容。</span>
          </div>
          <div className="flex items-center gap-2">
            <Button
              variant="ghost"
              size="sm"
              onClick={handleResetAll}
              disabled={phase1IsDefault && phase2IsDefault}
            >
              <RotateCcw size={14} className="mr-1" />
              全部恢复默认
            </Button>
            <Button size="sm" onClick={handleSave} disabled={!dirty}>
              <Save size={14} className="mr-1" />
              保存
            </Button>
          </div>
        </div>

        {/* Phase 1 */}
        <div className="space-y-2 mb-5">
          <div className="flex items-center justify-between">
            <label className="text-sm font-medium">
              Phase 1 — 诊断规划 Agent
              <span className="ml-2 text-xs text-muted-foreground font-normal">
                （AI 根据告警规划要执行的诊断命令）
              </span>
            </label>
            <div className="flex items-center gap-2 text-xs">
              {phase1IsDefault ? (
                <span className="text-green-600 dark:text-green-400">使用默认</span>
              ) : (
                <span className="text-amber-600 dark:text-amber-400">已自定义</span>
              )}
              {!phase1IsDefault && (
                <Button
                  variant="ghost"
                  size="sm"
                  className="h-7 px-2 text-xs"
                  onClick={() => setPhase1("")}
                >
                  <RotateCcw size={12} className="mr-1" /> 恢复默认
                </Button>
              )}
            </div>
          </div>
          <textarea
            value={phase1}
            onChange={(e) => setPhase1(e.target.value)}
            placeholder={defaults.phase1}
            className="w-full h-56 rounded-md border border-input bg-background px-3 py-2 text-sm font-mono resize-y focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
            spellCheck={false}
          />
          {phase1IsDefault && (
            <details className="text-xs text-muted-foreground">
              <summary className="cursor-pointer hover:text-foreground">预览内置默认提示词</summary>
              <pre className="mt-2 p-3 bg-muted/50 rounded text-xs whitespace-pre-wrap max-h-48 overflow-auto font-mono leading-relaxed">{defaults.phase1}</pre>
            </details>
          )}
        </div>

        {/* Phase 2 */}
        <div className="space-y-2">
          <div className="flex items-center justify-between">
            <label className="text-sm font-medium">
              Phase 2 — 根因综合 Agent
              <span className="ml-2 text-xs text-muted-foreground font-normal">
                （AI 综合告警 + metrics + 命令输出，生成根因 + 建议）
              </span>
            </label>
            <div className="flex items-center gap-2 text-xs">
              {phase2IsDefault ? (
                <span className="text-green-600 dark:text-green-400">使用默认</span>
              ) : (
                <span className="text-amber-600 dark:text-amber-400">已自定义</span>
              )}
              {!phase2IsDefault && (
                <Button
                  variant="ghost"
                  size="sm"
                  className="h-7 px-2 text-xs"
                  onClick={() => setPhase2("")}
                >
                  <RotateCcw size={12} className="mr-1" /> 恢复默认
                </Button>
              )}
            </div>
          </div>
          <textarea
            value={phase2}
            onChange={(e) => setPhase2(e.target.value)}
            placeholder={defaults.phase2}
            className="w-full h-56 rounded-md border border-input bg-background px-3 py-2 text-sm font-mono resize-y focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring"
            spellCheck={false}
          />
          {phase2IsDefault && (
            <details className="text-xs text-muted-foreground">
              <summary className="cursor-pointer hover:text-foreground">预览内置默认提示词</summary>
              <pre className="mt-2 p-3 bg-muted/50 rounded text-xs whitespace-pre-wrap max-h-48 overflow-auto font-mono leading-relaxed">{defaults.phase2}</pre>
            </details>
          )}
        </div>
      </SettingCard>
    </SettingsSection>
  );
};