import { useState, useEffect } from "react";
import { api } from "@/lib/api";
import { DataSourceForm, type DataSourceConfig } from "@/components/DataSourceForm";
import { Button } from "@/components/ui/button";
import { Plus, Database, Pencil, Trash2, Loader2, FolderOpen, Info, ChevronLeft, FileText, Search, Network } from "lucide-react";
import { Dialog, DialogContent, DialogHeader, DialogTitle } from "@/components/ui/dialog";
import { useAuthStore } from "@/store/authStore";
import { useProjectStore } from "@/store/projectStore";
import { useNavigate } from "react-router-dom";

const SOURCE_TYPES = [
  { id: "csv", name: "CSV Upload", icon: <FileText className="h-6 w-6 text-green-600" /> },
  { id: "bigquery", name: "BigQuery", icon: <Database className="h-6 w-6 text-blue-500" /> },
  { id: "postgres", name: "PostgreSQL", icon: <Database className="h-6 w-6 text-indigo-600" /> },
  { id: "supabase", name: "Supabase", icon: <Database className="h-6 w-6 text-emerald-500" /> },
  { id: "mysql", name: "MySQL", icon: <Database className="h-6 w-6 text-cyan-600" /> },
  { id: "oracle", name: "Oracle", icon: <Database className="h-6 w-6 text-red-600" /> },
  { id: "sqlserver", name: "SQL Server", icon: <Database className="h-6 w-6 text-red-500" /> },
  { id: "clickhouse", name: "ClickHouse", icon: <Database className="h-6 w-6 text-yellow-500" /> },
  { id: "trino", name: "Trino", icon: <Database className="h-6 w-6 text-pink-500" /> },
  { id: "snowflake", name: "Snowflake", icon: <Database className="h-6 w-6 text-blue-400" /> },
  { id: "athena-trino", name: "Athena (Trino)", icon: <Search className="h-6 w-6 text-purple-600" /> },
  { id: "redshift", name: "Redshift", icon: <Database className="h-6 w-6 text-purple-700" /> },
  { id: "databricks", name: "Databricks", icon: <Database className="h-6 w-6 text-orange-600" /> },
  { id: "emr-spark", name: "EMR (Spark)", icon: <Database className="h-6 w-6 text-indigo-800" /> },
  { id: "athena-spark", name: "Athena (Spark)", icon: <Search className="h-6 w-6 text-purple-500" /> },
  { id: "spark", name: "Spark", icon: <Database className="h-6 w-6 text-orange-500" /> },
  { id: "sqlite", name: "SQLite", icon: <Database className="h-6 w-6 text-blue-600" /> },
  { id: "parquet", name: "Parquet", icon: <FileText className="h-6 w-6 text-yellow-600" /> },
];

export function DataSources() {
  const [datasources, setDatasources] = useState<DataSourceConfig[]>([]);
  const [isLoading, setIsLoading] = useState(false);
  const [view, setView] = useState<"list" | "select-type">("list");
  const [isOpen, setIsOpen] = useState(false);
  const [editingDs, setEditingDs] = useState<DataSourceConfig | null>(null);
  const [selectedType, setSelectedType] = useState<string | null>(null);
  const { user } = useAuthStore();
  const { currentProject } = useProjectStore();
  const navigate = useNavigate();

  useEffect(() => {
    if (currentProject) {
      fetchDataSources();
    }
  }, [currentProject]);

  const fetchDataSources = async () => {
    if (!currentProject) return;
    setIsLoading(true);
    try {
      const data = await api.get<DataSourceConfig[]>(`/api/v1/datasources?project_id=${currentProject.id}`);
      setDatasources(data);
    } catch (e) {
      console.error("Failed to fetch data sources", e);
    } finally {
      setIsLoading(false);
    }
  }

  const handleCreate = () => {
    setEditingDs(null);
    setSelectedType(null);
    setView("select-type");
  };

  const handleSelectType = (typeId: string) => {
    setSelectedType(typeId);
    setIsOpen(true);
  };

  const handleEdit = (ds: DataSourceConfig) => {
    setEditingDs(ds);
    setSelectedType(ds.type);
    setIsOpen(true);
  };

  const handleDelete = async (id: number) => {
    if (!window.confirm("确定要删除这个数据源吗？")) return;
    try {
      await api.delete(`/api/v1/datasources/${id}`);
      fetchDataSources();
    } catch (e) {
      console.error("Failed to delete data source", e);
    }
  };

  const handleSubmit = async (data: Omit<DataSourceConfig, "id">) => {
    if (!currentProject) return;
    try {
      if (editingDs?.id) {
        await api.put(`/api/v1/datasources/${editingDs.id}`, { ...data, project_id: currentProject.id });
      } else {
        await api.post("/api/v1/datasources", { ...data, project_id: currentProject.id });
      }
      setIsOpen(false);
      fetchDataSources();
    } catch (e) {
      console.error("Failed to save data source", e);
      alert("保存失败: " + (e as any).message);
    }
  };

  const handleTest = async (type: string, config: Record<string, any>) => {
    try {
      const res = await api.post<{ success: boolean; message: string }>("/api/v1/datasources/test", { type, config });
      return res.success;
    } catch (e) {
      console.error("Test connection failed", e);
      throw e;
    }
  };

  if (view === "select-type") {
    return (
      <div className="h-full flex flex-col bg-[#F9FAFB]">
        <div className="px-12 py-8">
          <button 
            onClick={() => setView("list")}
            className="flex items-center text-zinc-500 hover:text-zinc-800 transition-colors mb-6 group"
          >
            <ChevronLeft className="h-4 w-4 mr-1 group-hover:-translate-x-0.5 transition-transform" />
            返回列表
          </button>
          
          <h1 className="text-2xl font-semibold text-zinc-800 mb-6">Connect an external data source</h1>
          
          <div className="bg-blue-50 border border-blue-100 rounded-md p-3 mb-8 flex items-start gap-3">
            <Info className="h-5 w-5 text-blue-600 mt-0.5 shrink-0" />
            <p className="text-sm text-blue-800">
              <span className="font-semibold">dbt integration</span> is available for PostgreSQL, MySQL, BigQuery, Redshift, and Snowflake (For Essential Plan and above). <a href="#" className="text-blue-600 hover:underline">Contact Us</a> to suggest new data sources.
            </p>
          </div>

          <div className="grid grid-cols-1 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4 gap-4">
            {SOURCE_TYPES.map((type) => (
              <button
                key={type.id}
                onClick={() => handleSelectType(type.id)}
                className="flex items-center gap-4 bg-white p-4 rounded-lg border border-zinc-200 hover:border-blue-500 hover:shadow-sm transition-all text-left group"
              >
                <div className="w-10 h-10 flex items-center justify-center rounded bg-zinc-50 group-hover:bg-blue-50 transition-colors">
                  {type.icon}
                </div>
                <span className="font-medium text-zinc-700 group-hover:text-blue-600 transition-colors">
                  {type.name}
                </span>
              </button>
            ))}
          </div>
        </div>

        <Dialog open={isOpen} onOpenChange={(open) => {
          setIsOpen(open);
          if (!open && !editingDs) setSelectedType(null);
        }}>
          <DialogContent className="sm:max-w-[600px] max-h-[90vh] overflow-y-auto">
            <DialogHeader>
              <DialogTitle>
                {editingDs ? "编辑数据源" : `新建 ${SOURCE_TYPES.find(t => t.id === selectedType)?.name || ""} 数据源`}
              </DialogTitle>
            </DialogHeader>
            <div className="py-4">
              <DataSourceForm 
                initialData={editingDs ? editingDs : (selectedType ? { name: "", type: selectedType, config: {} } : null)} 
                onSubmit={handleSubmit} 
                onTest={handleTest}
                onCancel={() => setIsOpen(false)}
              />
            </div>
          </DialogContent>
        </Dialog>
      </div>
    );
  }

  return (
    <div className="h-full flex flex-col bg-white">
      <div className="border-b border-zinc-100 px-8 py-5 flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-zinc-900">数据源配置</h1>
          <p className="text-sm text-zinc-500 mt-1">管理可用于问答的数据源连接</p>
        </div>
        <Button onClick={handleCreate} className="bg-indigo-600 hover:bg-indigo-700 text-white gap-2">
          <Plus className="h-4 w-4" />
          新建数据源
        </Button>
      </div>

      <div className="flex-1 overflow-auto p-8">
        {isLoading ? (
          <div className="flex justify-center items-center h-64">
            <Loader2 className="h-8 w-8 animate-spin text-zinc-400" />
          </div>
        ) : datasources.length === 0 ? (
          <div className="flex flex-col items-center justify-center h-64 border-2 border-dashed border-zinc-200 rounded-xl bg-zinc-50/50">
            <Database className="h-10 w-10 text-zinc-300 mb-3" />
            <p className="text-zinc-500 font-medium">暂无数据源</p>
            <p className="text-zinc-400 text-sm mt-1">点击右上角按钮添加第一个数据源</p>
          </div>
        ) : (
          <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
            {datasources.map((ds) => (
              <div 
                key={ds.id} 
                className="group relative bg-white border border-zinc-200 rounded-xl p-5 hover:shadow-md transition-all hover:border-zinc-300"
              >
                <div className="flex items-start justify-between mb-4">
                  <div className="flex items-center gap-3">
                    <div className="w-10 h-10 rounded-lg bg-indigo-50 flex items-center justify-center text-indigo-600">
                      <Database className="h-5 w-5" />
                    </div>
                    <div>
                      <h3 className="font-semibold text-zinc-900">{ds.name}</h3>
                      <p className="text-xs text-zinc-500 font-mono mt-0.5 uppercase">{ds.type}</p>
                    </div>
                  </div>
                  <div className="flex items-center gap-1 opacity-0 group-hover:opacity-100 transition-opacity">
                  <Button variant="ghost" size="icon" className="h-8 w-8 text-zinc-400 hover:text-blue-600" onClick={() => navigate(`/modeling/${ds.id}`)} title="Data Modeling">
                    <Network className="h-4 w-4" />
                  </Button>
                  <Button variant="ghost" size="icon" className="h-8 w-8 text-zinc-400 hover:text-zinc-600" onClick={() => handleEdit(ds)}>
                    <Pencil className="h-4 w-4" />
                  </Button>
                    <Button variant="ghost" size="icon" className="h-8 w-8 text-zinc-400 hover:text-red-600 hover:bg-red-50" onClick={() => handleDelete(ds.id!)}>
                      <Trash2 className="h-4 w-4" />
                    </Button>
                  </div>
                </div>
                
                <div className="space-y-2">
                  <div className="flex items-center justify-between text-sm">
                    <span className="text-zinc-500">Host</span>
                    <span className="font-medium text-zinc-700 truncate max-w-[150px]">
                      {ds.config.host || "Local / File"}
                    </span>
                  </div>
                  <div className="flex items-center justify-between text-sm">
                    <span className="text-zinc-500">Database</span>
                    <span className="font-medium text-zinc-700 truncate max-w-[150px]">
                      {ds.config.database || ds.config.file_path ? (ds.config.file_path?.split('/').pop()) : "-"}
                    </span>
                  </div>
                </div>
              </div>
            ))}
          </div>
        )}
      </div>

      <Dialog open={isOpen} onOpenChange={(open) => {
        setIsOpen(open);
        if (!open && !editingDs) setSelectedType(null);
      }}>
        <DialogContent className="sm:max-w-[600px] max-h-[90vh] overflow-y-auto">
          <DialogHeader>
            <DialogTitle>
              {editingDs ? `编辑 ${SOURCE_TYPES.find(t => t.id === editingDs.type)?.name || editingDs.type} 数据源` : `新建 ${SOURCE_TYPES.find(t => t.id === selectedType)?.name || ""} 数据源`}
            </DialogTitle>
          </DialogHeader>
          <div className="py-4">
            <DataSourceForm 
              initialData={editingDs ? editingDs : (selectedType ? { name: "", type: selectedType, config: {} } : null)} 
              onSubmit={handleSubmit} 
              onTest={handleTest}
              onCancel={() => setIsOpen(false)}
            />
          </div>
        </DialogContent>
      </Dialog>
    </div>
  );
}