import { useState } from 'react';
import { cn } from '@/lib/utils';
import { Card, CardContent, CardHeader, CardTitle, CardDescription } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Badge } from '@/components/ui/badge';
import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table';
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog';
import {
  CheckSquare,
  Plus,
  Search,
  Clock,
  CheckCircle,
  XCircle,
  User,
  ArrowRight,
  Settings,
  Eye,
  Edit,
  GitBranch,
} from 'lucide-react';
import { approvalFlows, approvalInstances } from '@/mocks/data';
import type { ApprovalFlow as ApprovalFlowType, ApprovalInstance } from '@/types';

export function ApprovalFlowManager() {
  const [activeTab, setActiveTab] = useState('instances');
  const [searchQuery, setSearchQuery] = useState('');
  const [statusFilter, setStatusFilter] = useState<string>('all');
  const [selectedInstance, setSelectedInstance] = useState<ApprovalInstance | null>(null);

  const filteredInstances = approvalInstances.filter((instance) => {
    const matchesSearch =
      instance.flowName.toLowerCase().includes(searchQuery.toLowerCase()) ||
      instance.applicantName.toLowerCase().includes(searchQuery.toLowerCase());
    const matchesStatus = statusFilter === 'all' || instance.status === statusFilter;
    return matchesSearch && matchesStatus;
  });

  const getStatusBadge = (status: ApprovalInstance['status']) => {
    const configs = {
      pending: { label: '审批中', className: 'border-amber-500/30 text-amber-400 bg-amber-500/10', icon: Clock },
      approved: { label: '已通过', className: 'border-emerald-500/30 text-emerald-400 bg-emerald-500/10', icon: CheckCircle },
      rejected: { label: '已拒绝', className: 'border-red-500/30 text-red-400 bg-red-500/10', icon: XCircle },
    };
    const config = configs[status];
    return (
      <Badge variant="outline" className={config.className}>
        <config.icon className="h-3 w-3 mr-1" />
        {config.label}
      </Badge>
    );
  };

  // 模拟审批流程图
  const renderFlowChart = (flow: ApprovalFlowType) => {
    return (
      <div className="flex items-center gap-2 overflow-x-auto py-4">
        {flow.nodes.map((node, index) => (
          <div key={node.id} className="flex items-center">
            <div
              className={cn(
                'px-4 py-2 rounded-lg border min-w-[100px] text-center',
                node.type === 'start' && 'bg-emerald-500/10 border-emerald-500/30 text-emerald-400',
                node.type === 'approval' && 'bg-blue-500/10 border-blue-500/30 text-blue-400',
                node.type === 'condition' && 'bg-amber-500/10 border-amber-500/30 text-amber-400',
                node.type === 'end' && 'bg-slate-500/10 border-slate-500/30 text-slate-400'
              )}
            >
              <p className="text-sm font-medium">{node.name}</p>
              {node.approvers && (
                <p className="text-xs text-slate-500 mt-1">{node.approvers.join(', ')}</p>
              )}
            </div>
            {index < flow.nodes.length - 1 && (
              <ArrowRight className="h-4 w-4 text-slate-600 mx-2" />
            )}
          </div>
        ))}
      </div>
    );
  };

  return (
    <div className="space-y-6">
      {/* Page Header */}
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-2xl font-bold text-slate-100">审批流程</h1>
          <p className="text-sm text-slate-500 mt-1">工作流管理与审批处理</p>
        </div>
        <div className="flex items-center gap-2">
          <Button variant="outline" className="border-slate-700 text-slate-300 hover:text-slate-100 hover:bg-slate-800">
            <Settings className="h-4 w-4 mr-2" />
            流程设计器
          </Button>
          <Button className="bg-blue-600 hover:bg-blue-700 text-white">
            <Plus className="h-4 w-4 mr-2" />
            新建流程
          </Button>
        </div>
      </div>

      {/* Stats Cards */}
      <div className="grid grid-cols-1 md:grid-cols-4 gap-4">
        <Card className="bg-slate-900 border-slate-800">
          <CardContent className="p-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="text-sm text-slate-500">待审批</p>
                <p className="text-2xl font-bold text-amber-400">
                  {approvalInstances.filter((i) => i.status === 'pending').length}
                </p>
              </div>
              <div className="p-3 rounded-lg bg-amber-500/10 text-amber-400">
                <Clock className="h-5 w-5" />
              </div>
            </div>
          </CardContent>
        </Card>
        <Card className="bg-slate-900 border-slate-800">
          <CardContent className="p-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="text-sm text-slate-500">已通过</p>
                <p className="text-2xl font-bold text-emerald-400">
                  {approvalInstances.filter((i) => i.status === 'approved').length}
                </p>
              </div>
              <div className="p-3 rounded-lg bg-emerald-500/10 text-emerald-400">
                <CheckCircle className="h-5 w-5" />
              </div>
            </div>
          </CardContent>
        </Card>
        <Card className="bg-slate-900 border-slate-800">
          <CardContent className="p-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="text-sm text-slate-500">已拒绝</p>
                <p className="text-2xl font-bold text-red-400">
                  {approvalInstances.filter((i) => i.status === 'rejected').length}
                </p>
              </div>
              <div className="p-3 rounded-lg bg-red-500/10 text-red-400">
                <XCircle className="h-5 w-5" />
              </div>
            </div>
          </CardContent>
        </Card>
        <Card className="bg-slate-900 border-slate-800">
          <CardContent className="p-4">
            <div className="flex items-center justify-between">
              <div>
                <p className="text-sm text-slate-500">流程模板</p>
                <p className="text-2xl font-bold text-slate-100">{approvalFlows.length}</p>
              </div>
              <div className="p-3 rounded-lg bg-blue-500/10 text-blue-400">
                <GitBranch className="h-5 w-5" />
              </div>
            </div>
          </CardContent>
        </Card>
      </div>

      {/* Tabs */}
      <Tabs value={activeTab} onValueChange={setActiveTab} className="w-full">
        <TabsList className="bg-slate-800 border border-slate-700">
          <TabsTrigger value="instances" className="data-[state=active]:bg-slate-700">
            审批实例
          </TabsTrigger>
          <TabsTrigger value="flows" className="data-[state=active]:bg-slate-700">
            流程模板
          </TabsTrigger>
          <TabsTrigger value="my-approvals" className="data-[state=active]:bg-slate-700">
            我的审批
          </TabsTrigger>
        </TabsList>

        <TabsContent value="instances" className="mt-4 space-y-4">
          {/* Filters */}
          <div className="flex items-center gap-3 flex-wrap">
            <div className="relative w-64">
              <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-slate-500" />
              <Input
                placeholder="搜索流程名称或申请人..."
                value={searchQuery}
                onChange={(e) => setSearchQuery(e.target.value)}
                className="pl-9 h-9 bg-slate-800/50 border-slate-700 text-slate-200 placeholder:text-slate-500"
              />
            </div>
            <select
              value={statusFilter}
              onChange={(e) => setStatusFilter(e.target.value)}
              className="h-9 px-3 rounded-md bg-slate-800/50 border border-slate-700 text-slate-200 text-sm"
            >
              <option value="all">全部状态</option>
              <option value="pending">审批中</option>
              <option value="approved">已通过</option>
              <option value="rejected">已拒绝</option>
            </select>
          </div>

          {/* Instances Table */}
          <Card className="bg-slate-900 border-slate-800">
            <CardContent className="p-0">
              <div className="border-t border-slate-800">
                <Table>
                  <TableHeader>
                    <TableRow className="border-slate-800 hover:bg-transparent">
                      <TableHead className="text-slate-400">流程名称</TableHead>
                      <TableHead className="text-slate-400">申请人</TableHead>
                      <TableHead className="text-slate-400">状态</TableHead>
                      <TableHead className="text-slate-400">当前节点</TableHead>
                      <TableHead className="text-slate-400">创建时间</TableHead>
                      <TableHead className="text-slate-400">完成时间</TableHead>
                      <TableHead className="text-slate-400 text-right">操作</TableHead>
                    </TableRow>
                  </TableHeader>
                  <TableBody>
                    {filteredInstances.map((instance) => (
                      <TableRow key={instance.id} className="border-slate-800 hover:bg-slate-800/50">
                        <TableCell>
                          <div className="flex items-center gap-2">
                            <GitBranch className="h-4 w-4 text-slate-500" />
                            <span className="text-sm font-medium text-slate-200">{instance.flowName}</span>
                          </div>
                        </TableCell>
                        <TableCell>
                          <div className="flex items-center gap-1 text-sm text-slate-300">
                            <User className="h-3.5 w-3.5 text-slate-500" />
                            {instance.applicantName}
                          </div>
                        </TableCell>
                        <TableCell>{getStatusBadge(instance.status)}</TableCell>
                        <TableCell>
                          <Badge variant="outline" className="border-slate-700 text-slate-400">
                            {instance.currentNode}
                          </Badge>
                        </TableCell>
                        <TableCell>
                          <span className="text-sm text-slate-400">
                            {new Date(instance.createdAt).toLocaleString()}
                          </span>
                        </TableCell>
                        <TableCell>
                          <span className="text-sm text-slate-400">
                            {instance.completedAt
                              ? new Date(instance.completedAt).toLocaleString()
                              : '--'}
                          </span>
                        </TableCell>
                        <TableCell className="text-right">
                          <div className="flex items-center justify-end gap-1">
                            <Button
                              variant="ghost"
                              size="sm"
                              className="h-8 text-slate-400 hover:text-slate-100"
                              onClick={() => setSelectedInstance(instance)}
                            >
                              <Eye className="h-4 w-4 mr-1" />
                              查看
                            </Button>
                            {instance.status === 'pending' && (
                              <>
                                <Button variant="ghost" size="sm" className="h-8 text-emerald-400 hover:text-emerald-400">
                                  <CheckCircle className="h-4 w-4 mr-1" />
                                  通过
                                </Button>
                                <Button variant="ghost" size="sm" className="h-8 text-red-400 hover:text-red-400">
                                  <XCircle className="h-4 w-4 mr-1" />
                                  拒绝
                                </Button>
                              </>
                            )}
                          </div>
                        </TableCell>
                      </TableRow>
                    ))}
                  </TableBody>
                </Table>
              </div>
            </CardContent>
          </Card>
        </TabsContent>

        <TabsContent value="flows" className="mt-4">
          <div className="grid grid-cols-1 gap-4">
            {approvalFlows.map((flow) => (
              <Card key={flow.id} className="bg-slate-900 border-slate-800">
                <CardHeader className="pb-2">
                  <div className="flex items-start justify-between">
                    <div className="flex items-center gap-3">
                      <div className="w-10 h-10 rounded-lg bg-blue-500/10 flex items-center justify-center">
                        <GitBranch className="h-5 w-5 text-blue-400" />
                      </div>
                      <div>
                        <CardTitle className="text-base text-slate-100">{flow.name}</CardTitle>
                        <CardDescription className="text-slate-500">{flow.description}</CardDescription>
                      </div>
                    </div>
                    <div className="flex items-center gap-2">
                      <Badge
                        variant="outline"
                        className={
                          flow.enabled
                            ? 'border-emerald-500/30 text-emerald-400 bg-emerald-500/10'
                            : 'border-slate-500/30 text-slate-400 bg-slate-500/10'
                        }
                      >
                        {flow.enabled ? '已启用' : '已停用'}
                      </Badge>
                      <Button variant="ghost" size="icon" className="h-8 w-8 text-slate-400 hover:text-slate-100">
                        <Edit className="h-4 w-4" />
                      </Button>
                    </div>
                  </div>
                </CardHeader>
                <CardContent>
                  <div className="bg-slate-950 rounded-lg p-4 overflow-x-auto">
                    {renderFlowChart(flow)}
                  </div>
                  <div className="flex items-center justify-between mt-4 text-sm text-slate-500">
                    <span>创建于 {new Date(flow.createdAt).toLocaleDateString()}</span>
                    <span>{flow.nodes.length} 个节点</span>
                  </div>
                </CardContent>
              </Card>
            ))}
          </div>
        </TabsContent>

        <TabsContent value="my-approvals" className="mt-4">
          <Card className="bg-slate-900 border-slate-800">
            <CardContent className="p-8">
              <div className="text-center">
                <CheckSquare className="h-12 w-12 mx-auto text-slate-500 mb-4" />
                <h3 className="text-lg font-medium text-slate-300 mb-2">暂无待审批事项</h3>
                <p className="text-sm text-slate-500">当前没有需要您审批的流程</p>
              </div>
            </CardContent>
          </Card>
        </TabsContent>
      </Tabs>

      {/* Instance Detail Dialog */}
      <Dialog open={!!selectedInstance} onOpenChange={() => setSelectedInstance(null)}>
        <DialogContent className="max-w-2xl bg-slate-900 border-slate-800">
          <DialogHeader>
            <DialogTitle className="text-slate-100 flex items-center gap-2">
              <GitBranch className="h-5 w-5 text-blue-400" />
              {selectedInstance?.flowName}
            </DialogTitle>
            <DialogDescription className="text-slate-500">
              申请人: {selectedInstance?.applicantName} · 创建于{' '}
              {selectedInstance && new Date(selectedInstance.createdAt).toLocaleString()}
            </DialogDescription>
          </DialogHeader>

          <div className="space-y-4">
            {/* Approval Timeline */}
            <div className="space-y-4">
              <h4 className="text-sm font-medium text-slate-300">审批进度</h4>
              <div className="space-y-4">
                <div className="flex gap-4">
                  <div className="flex flex-col items-center">
                    <div className="w-8 h-8 rounded-full bg-emerald-500/20 text-emerald-400 flex items-center justify-center">
                      <CheckCircle className="h-4 w-4" />
                    </div>
                    <div className="w-0.5 h-full bg-slate-700 mt-2" />
                  </div>
                  <div className="flex-1 pb-4">
                    <div className="flex items-center justify-between">
                      <span className="text-sm font-medium text-slate-200">提交申请</span>
                      <span className="text-xs text-slate-500">
                        {selectedInstance && new Date(selectedInstance.createdAt).toLocaleString()}
                      </span>
                    </div>
                    <p className="text-sm text-slate-400 mt-1">申请人: {selectedInstance?.applicantName}</p>
                  </div>
                </div>

                <div className="flex gap-4">
                  <div className="flex flex-col items-center">
                    <div
                      className={cn(
                        'w-8 h-8 rounded-full flex items-center justify-center',
                        selectedInstance?.status === 'approved'
                          ? 'bg-emerald-500/20 text-emerald-400'
                          : selectedInstance?.status === 'rejected'
                          ? 'bg-red-500/20 text-red-400'
                          : 'bg-amber-500/20 text-amber-400'
                      )}
                    >
                      {selectedInstance?.status === 'approved' ? (
                        <CheckCircle className="h-4 w-4" />
                      ) : selectedInstance?.status === 'rejected' ? (
                        <XCircle className="h-4 w-4" />
                      ) : (
                        <Clock className="h-4 w-4" />
                      )}
                    </div>
                  </div>
                  <div className="flex-1">
                    <div className="flex items-center justify-between">
                      <span className="text-sm font-medium text-slate-200">{selectedInstance?.currentNode}</span>
                      <span className="text-xs text-slate-500">
                        {selectedInstance?.completedAt
                          ? new Date(selectedInstance.completedAt).toLocaleString()
                          : '进行中'}
                      </span>
                    </div>
                    <p className="text-sm text-slate-400 mt-1">
                      {selectedInstance?.status === 'pending'
                        ? '等待审批人处理'
                        : selectedInstance?.status === 'approved'
                        ? '审批已通过'
                        : '审批已拒绝'}
                    </p>
                  </div>
                </div>
              </div>
            </div>
          </div>

          <DialogFooter className="gap-2">
            {selectedInstance?.status === 'pending' && (
              <>
                <Button variant="outline" className="border-red-700 text-red-400 hover:bg-red-500/10">
                  <XCircle className="h-4 w-4 mr-2" />
                  拒绝
                </Button>
                <Button className="bg-emerald-600 hover:bg-emerald-700 text-white">
                  <CheckCircle className="h-4 w-4 mr-2" />
                  通过
                </Button>
              </>
            )}
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  );
}