"use client";

import { useState } from "react";
import { useRouter } from "next/navigation";
import {
  Boxes,
  ChevronLeft,
  Loader2,
  MessageSquareText,
  Rocket,
  Terminal,
  Workflow,
} from "lucide-react";

import {
  ListPageLayout,
  ListPageSection,
} from "@/components/layout/list-page-layout";
import { Badge } from "@/components/ui/badge";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import {
  SelectionOptionCard,
  selectionOptionGridClassName,
} from "@/components/ui/selection-option-card";
import {
  assistantsApi,
  type AssistantType as ApiAssistantType,
  type AssistantUpsert,
  type KnowledgeRetrievalConfig,
} from "@/lib/api";
import { defaultTurnConfig } from "@/lib/turn-config";

type BuildMethod = "提示词" | "工作流" | "智能体平台" | "OpenCode";

const typeFromBuildMethod: Record<
  Exclude<BuildMethod, "智能体平台">,
  ApiAssistantType
> = {
  提示词: "prompt",
  工作流: "workflow",
  OpenCode: "opencode",
};

type AssistantTypeOption = {
  type: BuildMethod;
  label: string;
  description: string;
  icon: React.ReactNode;
  /** 提示词、工作流、智能体平台已落地；OpenCode 暂时显示即将上线 */
  available: boolean;
};

const assistantTypeOptions: AssistantTypeOption[] = [
  {
    type: "提示词",
    label: "使用提示词构建",
    description: "通过提示词、模型与语音快速搭建对话助手，适合大多数场景。",
    icon: <MessageSquareText size={20} />,
    available: true,
  },
  {
    type: "工作流",
    label: "使用工作流构建",
    description: "用可视化编排串联多个节点，适合多步骤、带分支的复杂流程。",
    icon: <Workflow size={20} />,
    available: true,
  },
  {
    type: "智能体平台",
    label: "从智能体平台创建",
    description:
      "接入 Dify、FastGPT 等智能体平台，复用平台中的提示词、知识库和工作流配置。",
    icon: <Boxes size={20} />,
    available: true,
  },
  {
    type: "OpenCode",
    label: "使用 OpenCode 构建",
    description: "对接 OpenCode 服务，通过提示词驱动代码助手并支持实时语音对话。",
    icon: <Terminal size={20} />,
    available: false,
  },
];

function defaultKnowledgeRetrievalConfig(): KnowledgeRetrievalConfig {
  return {
    mode: "automatic",
    topN: 5,
    scoreThreshold: 0,
  };
}

function baseUpsert(over: Partial<AssistantUpsert>): AssistantUpsert {
  return {
    name: "",
    type: "prompt",
    runtimeMode: "pipeline",
    greeting: "",
    enableInterrupt: true,
    turnConfig: defaultTurnConfig(),
    startup: {
      executionMode: "sequential",
      openingMode: "interruptible",
      entryMode: "wait_user",
      actions: [],
      openingMessage: null,
    },
    visionEnabled: false,
    visionModelResourceId: null,
    visionPromptMode: "runtime",
    visionPrompt: "",
    modelResourceIds: {},
    knowledgeBaseId: null,
    knowledgeRetrievalConfig: defaultKnowledgeRetrievalConfig(),
    toolIds: [],
    prompt: "",
    dynamicVariableDefinitions: {},
    analysisConfig: {
      enabled: false,
      modelResourceId: "",
      fields: [],
    },
    apiUrl: "",
    apiKey: "",
    appId: "",
    graph: {},
    ...over,
  };
}

export function CreateAssistantPage() {
  const router = useRouter();
  const [draftName, setDraftName] = useState("");
  const [draftType, setDraftType] = useState<BuildMethod | null>(null);
  const [creating, setCreating] = useState(false);
  const [createError, setCreateError] = useState<string | null>(null);

  async function handleCreate() {
    if (!draftName.trim() || !draftType || creating) {
      return;
    }

    setCreating(true);
    setCreateError(null);
    try {
      const assistantType: ApiAssistantType =
        draftType === "智能体平台"
          ? "dify"
          : typeFromBuildMethod[draftType];
      const created = await assistantsApi.create(
        baseUpsert({
          name: draftName.trim(),
          type: assistantType,
        }),
      );
      router.push(`/assistants/${created.id}`);
    } catch (error) {
      setCreateError(error instanceof Error ? error.message : "创建失败");
      setCreating(false);
    }
  }

  return (
    <ListPageLayout
      title="创建助手"
      className="max-w-[1180px]"
      description="先为助手取个名字，再选择构建方式。确认后将立即创建助手并进入编辑页。"
      action={
        <Button
          variant="outline"
          className="w-full shrink-0 gap-2 border-hairline-strong text-muted-foreground hover:text-foreground sm:w-auto"
          onClick={() => router.push("/assistants")}
        >
          <ChevronLeft size={16} />
          返回列表
        </Button>
      }
    >
      <ListPageSection>
        <label className="block">
          <div className="mb-2 text-sm font-medium text-foreground">助手名称</div>
          <Input
            value={draftName}
            autoFocus
            onChange={(event) => setDraftName(event.target.value)}
            placeholder="请输入助手名称"
            className="border-hairline-strong bg-background text-foreground placeholder:text-muted-soft"
          />
        </label>
      </ListPageSection>

      <section className="flex flex-col gap-3">
        <div className="text-sm font-medium text-foreground">构建方式</div>

        <div className={selectionOptionGridClassName}>
          {assistantTypeOptions.map((option) => (
            <SelectionOptionCard
              key={option.type}
              selected={draftType === option.type}
              icon={option.icon}
              title={option.label}
              description={option.description}
              onClick={() => setDraftType(option.type)}
              unselectedTrailing={
                !option.available ? (
                  <Badge
                    variant="secondary"
                    className="h-6 bg-surface-strong px-3 text-xs text-muted-foreground"
                  >
                    即将上线
                  </Badge>
                ) : undefined
              }
            />
          ))}
        </div>
      </section>

      <div className="flex items-center justify-end gap-3">
        {createError && (
          <span className="text-xs text-destructive">{createError}</span>
        )}
        <Button
          variant="outline"
          className="border-hairline-strong text-muted-foreground hover:text-foreground"
          disabled={creating}
          onClick={() => router.push("/assistants")}
        >
          取消
        </Button>
        <Button
          className="gap-2"
          disabled={!draftName.trim() || !draftType || creating}
          onClick={() => void handleCreate()}
        >
          {creating ? (
            <Loader2 size={16} className="animate-spin" />
          ) : (
            <Rocket size={16} />
          )}
          创建助手
        </Button>
      </div>
    </ListPageLayout>
  );
}