"use client"

import {useCallback, useEffect, useState} from "react"
import {toast} from "sonner"
import {Button} from "@/components/ui/button"
import {Input} from "@/components/ui/input"
import {Label} from "@/components/ui/label"
import {Textarea} from "@/components/ui/textarea"
import {Switch} from "@/components/ui/switch"
import {Spinner} from "@/components/ui/spinner"
import {Dialog, DialogContent, DialogDescription, DialogFooter, DialogHeader, DialogTitle} from "@/components/ui/dialog"
import {Table, TableBody, TableCell, TableHead, TableHeader, TableRow} from "@/components/ui/table"
import {Clock, Edit2, Info, Plus, RefreshCw, Trash2} from "lucide-react"

import {AdminService, CreateScheduleRequest, Schedule, TaskMeta, UpdateScheduleRequest} from "@/lib/services/admin"
import {buildTaskPayload} from "@/lib/task-param-utils"
import {ErrorInline} from "@/components/layout/error"
import {LoadingStateWithBorder} from "@/components/layout/loading"
import {EmptyStateWithBorder} from "@/components/layout/empty"

export function TaskSchedulesManager() {
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<Error | null>(null)
  const [schedules, setSchedules] = useState<Schedule[]>([])
  const [taskTypes, setTaskTypes] = useState<TaskMeta[]>([])

  // Modal States
  const [dialogOpen, setDialogOpen] = useState(false)
  const [submitLoading, setSubmitLoading] = useState(false)
  const [editingSchedule, setEditingSchedule] = useState<Schedule | null>(null)

  // Delete States
  const [deleteOpen, setDeleteOpen] = useState(false)
  const [deletingId, setDeletingId] = useState<string | null>(null)
  const [deleteLoading, setDeleteLoading] = useState(false)

  // Form Fields
  const [name, setName] = useState("")
  const [selectedTaskType, setSelectedTaskType] = useState("")
  const [cron, setCron] = useState("")
  const [isActive, setIsActive] = useState(true)
  const [paramValues, setParamValues] = useState<Record<string, string>>({})

  // Fetch Schedules & Task Types
  const fetchData = useCallback(async () => {
    try {
      setLoading(true)
      setError(null)
      const [schedulesData, taskTypesData] = await Promise.all([
        AdminService.listSchedules(),
        AdminService.getTaskTypes()
      ])
      setSchedules(schedulesData || [])
      setTaskTypes(taskTypesData || [])
    } catch (err) {
      setError(err instanceof Error ? err : new Error("加载定时任务配置失败"))
    } finally {
      setLoading(false)
    }
  }, [])

  useEffect(() => {
    fetchData()
  }, [fetchData])

  // Track task type selection to initialize parameters
  useEffect(() => {
    if (selectedTaskType) {
      const targetTask = taskTypes.find(t => t.type === selectedTaskType)
      if (editingSchedule && editingSchedule.task_type === selectedTaskType) {
        // Parse existing payload when editing the same task type
        try {
          const parsed = JSON.parse(editingSchedule.payload || "{}")
          const values: Record<string, string> = {}
          targetTask?.params?.forEach(p => {
            values[p.name] = String(parsed[p.name] ?? "")
          })
          setParamValues(values)
        } catch {
          const initialValues: Record<string, string> = {}
          targetTask?.params?.forEach(p => {
            initialValues[p.name] = ""
          })
          setParamValues(initialValues)
        }
      } else {
        const initialValues: Record<string, string> = {}
        targetTask?.params?.forEach(p => {
          initialValues[p.name] = ""
        })
        setParamValues(initialValues)
      }
    } else {
      setParamValues({})
    }
  }, [selectedTaskType, taskTypes, editingSchedule])

  const handleToggleActive = async (schedule: Schedule) => {
    try {
      const updated = await AdminService.updateSchedule(schedule.id, {
        name: schedule.name,
        task_type: schedule.task_type,
        cron: schedule.cron,
        payload: schedule.payload,
        is_active: !schedule.is_active
      })

      setSchedules(prev => prev.map(s => s.id === schedule.id ? updated : s))
      toast.success(updated.is_active ? `已启用定时任务：${updated.name}` : `已停用定时任务：${updated.name}`)
    } catch (err) {
      toast.error("修改任务状态失败", {
        description: err instanceof Error ? err.message : "未知错误"
      })
    }
  }

  const openCreateDialog = () => {
    setEditingSchedule(null)
    setName("")
    setSelectedTaskType(taskTypes[0]?.type || "")
    setCron("0 */2 * * *")
    setIsActive(true)
    setParamValues({})
    setDialogOpen(true)
  }

  const openEditDialog = (schedule: Schedule) => {
    setEditingSchedule(schedule)
    setName(schedule.name)
    setSelectedTaskType(schedule.task_type)
    setCron(schedule.cron)
    setIsActive(schedule.is_active)
    setDialogOpen(true)
  }

  const handleSubmit = async () => {
    if (!name.trim()) {
      toast.error("任务名称不能为空")
      return
    }
    if (!cron.trim()) {
      toast.error("Cron 表达式不能为空")
      return
    }

    try {
      setSubmitLoading(true)

      const targetTask = taskTypes.find(t => t.type === selectedTaskType)
      let payloadStr = '{}'

      if (targetTask?.params && targetTask.params.length > 0) {
        const { payload, error } = buildTaskPayload(targetTask.params, paramValues)
        if (error) {
          toast.error(error)
          setSubmitLoading(false)
          return
        }
        payloadStr = payload ?? '{}'
      }

      if (editingSchedule) {
        const req: UpdateScheduleRequest = {
          name,
          task_type: selectedTaskType,
          cron,
          payload: payloadStr,
          is_active: isActive
        }
        const updated = await AdminService.updateSchedule(editingSchedule.id, req)
        setSchedules(prev => prev.map(s => s.id === editingSchedule.id ? updated : s))
        toast.success("定时任务更新成功")
      } else {
        const req: CreateScheduleRequest = {
          name,
          task_type: selectedTaskType,
          cron,
          payload: payloadStr,
          is_active: isActive
        }
        const created = await AdminService.createSchedule(req)
        setSchedules(prev => [created, ...prev])
        toast.success("定时任务创建成功")
      }

      setDialogOpen(false)
    } catch (err) {
      toast.error("提交失败", {
        description: err instanceof Error ? err.message : "未知错误"
      })
    } finally {
      setSubmitLoading(false)
    }
  }

  const openDeleteDialog = (id: string) => {
    setDeletingId(id)
    setDeleteOpen(true)
  }

  const handleDelete = async () => {
    if (!deletingId) return
    try {
      setDeleteLoading(true)
      await AdminService.deleteSchedule(deletingId)
      setSchedules(prev => prev.filter(s => s.id !== deletingId))
      toast.success("定时任务删除成功")
      setDeleteOpen(false)
    } catch (err) {
      toast.error("删除失败", {
        description: err instanceof Error ? err.message : "未知错误"
      })
    } finally {
      setDeleteLoading(false)
    }
  }

  const getSelectedTaskMeta = () => {
    return taskTypes.find(t => t.type === selectedTaskType)
  }

  const getTaskName = (type: string) => {
    const meta = taskTypes.find(t => t.type === type)
    return meta ? meta.name : type
  }

  return (
    <div className="space-y-6">
      <br/>
      <div className="flex items-center justify-between">
        <div className="flex items-center gap-2">
          <Button variant="outline" size="sm" onClick={fetchData} disabled={loading}>
            {loading ? <Spinner className="size-4" /> : <RefreshCw className="size-4" />}
            刷新
          </Button>
          <Button size="sm" onClick={openCreateDialog} disabled={taskTypes.length === 0} variant={'secondary'}>
            <Plus className="size-4 mr-1" />
            新增定时任务
          </Button>
        </div>
      </div>

      {error ? (
        <div className="p-8 border border-dashed rounded-lg bg-card">
          <ErrorInline error={error} onRetry={fetchData} className="justify-center" />
        </div>
      ) : loading && schedules.length === 0 ? (
        <LoadingStateWithBorder icon={Clock} description="加载定时任务配置中..." />
      ) : schedules.length === 0 ? (
        <EmptyStateWithBorder icon={Clock} description="暂无定时任务配置，点击上方按钮新增" />
      ) : (
        <div className="rounded-lg border bg-card">
          <Table className="min-w-[800px]">
            <TableHeader>
              <TableRow className="hover:bg-transparent">
                <TableHead className="w-[180px]">任务名称</TableHead>
                <TableHead className="w-[160px]">关联异步任务</TableHead>
                <TableHead className="w-[120px]">Cron 表达式</TableHead>
                <TableHead className="min-w-[200px]">执行参数 (Payload)</TableHead>
                <TableHead className="w-[100px] text-center">启用状态</TableHead>
                <TableHead className="w-[120px] text-right">操作</TableHead>
              </TableRow>
            </TableHeader>
            <TableBody>
              {schedules.map((schedule) => (
                <TableRow key={schedule.id}>
                  <TableCell className="font-medium">{schedule.name}</TableCell>
                  <TableCell>
                    <div className="flex flex-col gap-0.5">
                      <span className="text-xs font-semibold">{getTaskName(schedule.task_type)}</span>
                      <span className="font-mono text-[10px] text-muted-foreground">{schedule.task_type}</span>
                    </div>
                  </TableCell>
                  <TableCell className="font-mono text-xs text-blue-600 dark:text-blue-400 font-semibold">
                    {schedule.cron}
                  </TableCell>
                  <TableCell className="max-w-[300px] truncate">
                    <code className="text-xs bg-muted/60 px-1 py-0.5 rounded font-mono">
                      {schedule.payload || "{}"}
                    </code>
                  </TableCell>
                  <TableCell className="text-center">
                    <div className="flex justify-center">
                      <Switch
                        checked={schedule.is_active}
                        onCheckedChange={() => handleToggleActive(schedule)}
                      />
                    </div>
                  </TableCell>
                  <TableCell className="text-right">
                    <div className="flex items-center justify-end gap-1.5">
                      <Button
                        variant="ghost"
                        size="icon"
                        className="h-7 w-7 text-muted-foreground hover:text-foreground"
                        onClick={() => openEditDialog(schedule)}
                      >
                        <Edit2 className="size-3.5" />
                      </Button>
                      <Button
                        variant="ghost"
                        size="icon"
                        className="h-7 w-7 text-destructive hover:text-destructive/90"
                        onClick={() => openDeleteDialog(schedule.id)}
                      >
                        <Trash2 className="size-3.5" />
                      </Button>
                    </div>
                  </TableCell>
                </TableRow>
              ))}
            </TableBody>
          </Table>
        </div>
      )}

      {/* Add / Edit Dialog */}
      <Dialog open={dialogOpen} onOpenChange={setDialogOpen}>
        <DialogContent className="sm:max-w-[500px]">
          <DialogHeader>
            <DialogTitle>{editingSchedule ? "修改定时任务" : "新增定时任务"}</DialogTitle>
            <DialogDescription>
              配置定时任务的调度参数和运行载荷。
            </DialogDescription>
          </DialogHeader>

          <div className="grid gap-4 py-4">
            <div className="grid gap-2">
              <Label htmlFor="sched-name">任务名称</Label>
              <Input
                id="sched-name"
                placeholder="例如：每日数据清理"
                value={name}
                onChange={(e) => setName(e.target.value)}
                className="text-xs"
              />
            </div>

            <div className="grid gap-2">
              <Label htmlFor="sched-type">关联异步任务</Label>
              <select
                id="sched-type"
                value={selectedTaskType}
                onChange={(e) => setSelectedTaskType(e.target.value)}
                disabled={!!editingSchedule}
                className="flex h-8 w-full rounded-md border border-input bg-background px-3 py-1.5 text-xs shadow-sm transition-colors file:border-0 file:bg-transparent file:text-sm file:font-medium placeholder:text-muted-foreground focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:cursor-not-allowed disabled:opacity-50"
              >
                {taskTypes.map(t => (
                  <option key={t.type} value={t.type}>
                    {t.name} ({t.type})
                  </option>
                ))}
              </select>
            </div>

            <div className="grid gap-2">
              <Label htmlFor="sched-cron">Cron 表达式</Label>
              <Input
                id="sched-cron"
                placeholder="e.g. 0 */2 * * * 或 @daily"
                value={cron}
                onChange={(e) => setCron(e.target.value)}
                className="text-xs font-mono"
              />
              <p className="text-[10px] text-muted-foreground">使用标准 5 位 Cron 字段格式（分钟、小时、日期、月份、星期几）。</p>
            </div>

            <div className="flex items-center justify-between rounded-lg border p-3">
              <div className="space-y-0.5">
                <Label htmlFor="sched-active">启用状态</Label>
                <p className="text-[10px] text-muted-foreground">决定此定时任务是否会定时触发执行。</p>
              </div>
              <Switch
                id="sched-active"
                checked={isActive}
                onCheckedChange={setIsActive}
              />
            </div>

            {(() => {
              const targetTask = getSelectedTaskMeta()
              if (!targetTask || !targetTask.params || targetTask.params.length === 0) {
                return (
                  <div className="flex items-center gap-2 text-xs text-muted-foreground bg-muted/40 p-3 rounded-md border border-dashed">
                    <Info className="h-4 w-4 shrink-0" />
                    <span>所选任务类型不需要运行参数参数。</span>
                  </div>
                )
              }
              return (
                <div className="space-y-4 pt-2 border-t">
                  <Label className="text-xs font-semibold">运行参数配置 (Payload)</Label>
                  {targetTask.params.map((param) => (
                    <div key={param.name} className="grid gap-2 pl-2 border-l-2 border-muted">
                      <Label htmlFor={`param-${param.name}`} className="flex items-center gap-1 text-xs">
                        {param.label}
                        {param.required && <span className="text-destructive font-bold">*</span>}
                      </Label>
                      {param.type === 'text' ? (
                        <Textarea
                          id={`param-${param.name}`}
                          placeholder={param.placeholder}
                          className="text-xs min-h-[70px]"
                          value={paramValues[param.name] || ""}
                          onChange={(e) => setParamValues(prev => ({ ...prev, [param.name]: e.target.value }))}
                        />
                      ) : param.type === 'boolean' ? (
                        <div className="flex items-center gap-2 pt-1 h-9">
                          <Switch
                            id={`param-${param.name}`}
                            checked={paramValues[param.name] === 'true'}
                            onCheckedChange={(checked) => setParamValues(prev => ({ ...prev, [param.name]: checked ? 'true' : 'false' }))}
                          />
                          <span className="text-xs text-muted-foreground">
                            {paramValues[param.name] === 'true' ? '开启' : '关闭'}
                          </span>
                        </div>
                      ) : (
                        <Input
                          id={`param-${param.name}`}
                          type={param.type === 'number' ? 'number' : 'text'}
                          placeholder={param.placeholder}
                          className="text-xs"
                          value={paramValues[param.name] || ""}
                          onChange={(e) => setParamValues(prev => ({ ...prev, [param.name]: e.target.value }))}
                        />
                      )}
                      {param.description && (
                        <p className="text-[10px] text-muted-foreground">{param.description}</p>
                      )}
                    </div>
                  ))}
                </div>
              )
            })()}
          </div>

          <DialogFooter>
            <Button variant="ghost" onClick={() => setDialogOpen(false)} disabled={submitLoading} className="h-8 text-xs">
              取消
            </Button>
            <Button onClick={handleSubmit} disabled={submitLoading} className="h-8 text-xs">
              {submitLoading && <Spinner className="size-3 mr-1" />}
              {editingSchedule ? '保存修改' : '确认创建'}
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>

      {/* Delete Confirmation */}
      <Dialog open={deleteOpen} onOpenChange={setDeleteOpen}>
        <DialogContent className="sm:max-w-[400px]">
          <DialogHeader>
            <DialogTitle>删除定时任务</DialogTitle>
            <DialogDescription>
              确定要删除此定时任务吗？该操作不可撤销，且会立即取消其在调度器中的调度计划。
            </DialogDescription>
          </DialogHeader>
          <DialogFooter className="gap-2 sm:gap-0">
            <Button variant="ghost" onClick={() => setDeleteOpen(false)} disabled={deleteLoading} className="h-8 text-xs">
              取消
            </Button>
            <Button variant="destructive" onClick={handleDelete} disabled={deleteLoading} className="h-8 text-xs">
              {deleteLoading && <Spinner className="size-3 mr-1" />}
              确认删除
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  )
}