"use client"

import * as React from "react"
import { CalendarPlusIcon, Trash2Icon } from "lucide-react"
import { toast } from "sonner"

import {
  cancelFacilitySession,
  createFacilitySession,
  getFacilities,
  getFacilitySessions,
} from "@/lib/api/facilities"
import type { Facility, FacilitySession } from "@/lib/models/facility"
import { useFetch } from "@/lib/use-fetch"
import { useMutation } from "@/lib/use-mutation"
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog"
import { Button } from "@/components/ui/button"
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"
import { Spinner } from "@/components/ui/spinner"
import { Tabs, TabsContent, TabsList, TabsTrigger } from "@/components/ui/tabs"
import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip"
import { DataTable, type DataTableColumn } from "@/components/hexa/data-table"
import { PageHeader } from "@/components/hexa/page-header"
import { PageSkeleton } from "@/components/hexa/page-skeleton"
import { StatusBadge } from "@/components/hexa/status-badge"
import { AdhocBookingTab } from "@/components/hexa/views/adhoc-booking-tab"
import { BookingDashboardTab } from "@/components/hexa/views/booking-dashboard-tab"
import { BookingInvoicesTab } from "@/components/hexa/views/booking-invoices-tab"
import { BookingRosterTab } from "@/components/hexa/views/booking-roster-tab"
import { RfidTagsTab } from "@/components/hexa/views/rfid-tags-tab"
import { TimeBankCardsTab } from "@/components/hexa/views/time-bank-cards-tab"

function formatDateTime(iso: string) {
  return new Date(iso).toLocaleString(undefined, {
    day: "numeric",
    month: "short",
    hour: "numeric",
    minute: "2-digit",
  })
}

/** `datetime-local` input value in local time, e.g. "2026-09-20T18:30". */
function toLocalInputValue(date: Date) {
  const pad = (n: number) => String(n).padStart(2, "0")
  return `${date.getFullYear()}-${pad(date.getMonth() + 1)}-${pad(date.getDate())}T${pad(date.getHours())}:${pad(date.getMinutes())}`
}

function BookingsView() {
  const facilitiesFetch = useFetch(() => getFacilities(true))
  const facilities = facilitiesFetch.data ?? []

  if (facilitiesFetch.loading) {
    return <PageSkeleton variant="stats-table" />
  }

  return (
    <div className="flex flex-col gap-4">
      <PageHeader
        title="Bookings"
        description="Dashboard, scheduled sessions, ad-hoc reservations, the booking roster, invoices, RFID tags and time-bank cards"
      />

      <Tabs defaultValue="dashboard" className="gap-4">
        <TabsList>
          <TabsTrigger value="dashboard">Dashboard</TabsTrigger>
          <TabsTrigger value="sessions">Sessions</TabsTrigger>
          <TabsTrigger value="adhoc">Book Now</TabsTrigger>
          <TabsTrigger value="roster">Roster &amp; Check-in</TabsTrigger>
          <TabsTrigger value="invoices">Invoices</TabsTrigger>
          <TabsTrigger value="rfid-tags">RFID Tags</TabsTrigger>
          <TabsTrigger value="time-bank-cards">Time Bank Cards</TabsTrigger>
        </TabsList>

        <TabsContent value="dashboard">
          <BookingDashboardTab />
        </TabsContent>
        <TabsContent value="sessions">
          <SessionsTab facilities={facilities} />
        </TabsContent>
        <TabsContent value="adhoc">
          <AdhocBookingTab facilities={facilities} />
        </TabsContent>
        <TabsContent value="roster">
          <BookingRosterTab facilities={facilities} />
        </TabsContent>
        <TabsContent value="invoices">
          <BookingInvoicesTab />
        </TabsContent>
        <TabsContent value="rfid-tags">
          <RfidTagsTab />
        </TabsContent>
        <TabsContent value="time-bank-cards">
          <TimeBankCardsTab facilities={facilities} />
        </TabsContent>
      </Tabs>
    </div>
  )
}

// ---------- Sessions ----------

interface SessionsTabProps {
  facilities: Facility[]
}

function SessionsTab({ facilities }: SessionsTabProps) {
  const scheduledFacilities = facilities.filter((f) => f.bookingMode === "Scheduled")

  const [facilityFilter, setFacilityFilter] = React.useState("all")
  const sessionsFetch = useFetch(() =>
    getFacilitySessions(facilityFilter === "all" ? {} : { facilityId: facilityFilter })
  )
  const sessions = sessionsFetch.data ?? []

  const [dialogOpen, setDialogOpen] = React.useState(false)
  const [cancelTarget, setCancelTarget] = React.useState<FacilitySession | null>(null)
  const { busy: cancelling, run: runCancel } = useMutation()

  const filterOptions = [
    { label: "All facilities", value: "all" },
    ...scheduledFacilities.map((f) => ({ label: f.name, value: f.facilityId })),
  ]

  async function confirmCancel() {
    if (!cancelTarget) return
    const target = cancelTarget
    setCancelTarget(null)
    try {
      await runCancel(() => cancelFacilitySession(target.facilitySessionId))
      toast.success("Session cancelled")
      sessionsFetch.reload()
    } catch {
      // run() already toasted the real error.
    }
  }

  const columns: DataTableColumn<FacilitySession>[] = [
    { key: "facility", header: "Facility", cell: (row) => row.facilityName ?? "-" },
    { key: "start", header: "Start", cell: (row) => formatDateTime(row.startTime) },
    { key: "end", header: "End", cell: (row) => formatDateTime(row.endTime) },
    {
      key: "capacity",
      header: "Booked / Capacity",
      cell: (row) => `${row.bookedCount} / ${row.capacity}`,
    },
    {
      key: "status",
      header: "Status",
      cell: (row) =>
        row.isCancelled ? (
          <StatusBadge status="danger">Cancelled</StatusBadge>
        ) : (
          <StatusBadge status="success">Scheduled</StatusBadge>
        ),
    },
    {
      key: "actions",
      header: "Actions",
      className: "text-center",
      cell: (row) =>
        row.isCancelled ? null : (
          <div className="flex justify-center">
            <Tooltip>
              <TooltipTrigger
                render={
                  <Button
                    variant="outline"
                    size="icon-sm"
                    aria-label="Cancel session"
                    onClick={() => setCancelTarget(row)}
                  >
                    <Trash2Icon />
                  </Button>
                }
              />
              <TooltipContent>Cancel session</TooltipContent>
            </Tooltip>
          </div>
        ),
    },
  ]

  return (
    <div className="flex flex-col gap-4">
      <div className="flex flex-wrap items-center justify-between gap-3">
        <div className="flex flex-col gap-1.5">
          <Label>Facility</Label>
          <Select items={filterOptions} value={facilityFilter} onValueChange={(v) => setFacilityFilter(v ?? "all")}>
            <SelectTrigger className="w-56">
              <SelectValue placeholder="All facilities" />
            </SelectTrigger>
            <SelectContent>
              {filterOptions.map((opt) => (
                <SelectItem key={opt.value} value={opt.value}>
                  {opt.label}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
        </div>
        <Button onClick={() => setDialogOpen(true)} disabled={scheduledFacilities.length === 0}>
          <CalendarPlusIcon />
          Schedule Session
        </Button>
      </div>

      {sessionsFetch.loading ? (
        <div className="flex justify-center py-10">
          <Spinner className="size-6" />
        </div>
      ) : (
        <DataTable
          columns={columns}
          rows={sessions}
          rowKey={(row) => row.facilitySessionId}
          emptyMessage="No sessions scheduled yet."
          renderMobileCard={(row) => (
            <div className="flex flex-col gap-2">
              <div className="flex items-start justify-between gap-2">
                <div>
                  <p className="font-medium">{row.facilityName ?? "-"}</p>
                  <p className="text-sm text-muted-foreground">
                    {formatDateTime(row.startTime)} - {formatDateTime(row.endTime)}
                  </p>
                </div>
                {row.isCancelled ? (
                  <StatusBadge status="danger">Cancelled</StatusBadge>
                ) : (
                  <StatusBadge status="success">Scheduled</StatusBadge>
                )}
              </div>
              <div className="flex items-center justify-between border-t pt-2">
                <span className="text-sm text-muted-foreground">
                  {row.bookedCount} / {row.capacity} booked
                </span>
                {!row.isCancelled && (
                  <Button variant="outline" size="icon-sm" aria-label="Cancel session" onClick={() => setCancelTarget(row)}>
                    <Trash2Icon />
                  </Button>
                )}
              </div>
            </div>
          )}
        />
      )}

      <ScheduleSessionDialog
        open={dialogOpen}
        onOpenChange={setDialogOpen}
        facilities={scheduledFacilities}
        onScheduled={sessionsFetch.reload}
      />

      <AlertDialog open={!!cancelTarget} onOpenChange={(open) => !open && setCancelTarget(null)}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>Cancel this session?</AlertDialogTitle>
            <AlertDialogDescription>
              Existing bookings for this session will need to be handled separately. This cannot be undone.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel>Keep Session</AlertDialogCancel>
            <AlertDialogAction onClick={confirmCancel} disabled={cancelling}>
              Cancel Session
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </div>
  )
}

interface ScheduleSessionDialogProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  facilities: Facility[]
  onScheduled: () => void
}

function ScheduleSessionDialog({ open, onOpenChange, facilities, onScheduled }: ScheduleSessionDialogProps) {
  const [facilityId, setFacilityId] = React.useState("")
  const [startTime, setStartTime] = React.useState("")
  const [endTime, setEndTime] = React.useState("")
  const [capacity, setCapacity] = React.useState("")
  const { busy, run } = useMutation()
  const [prevOpen, setPrevOpen] = React.useState(open)

  if (open !== prevOpen) {
    setPrevOpen(open)
    if (open) {
      const now = new Date()
      now.setMinutes(0, 0, 0)
      now.setHours(now.getHours() + 1)
      const later = new Date(now.getTime() + 60 * 60 * 1000)
      setFacilityId(facilities[0]?.facilityId ?? "")
      setStartTime(toLocalInputValue(now))
      setEndTime(toLocalInputValue(later))
      setCapacity("")
    }
  }

  const facilityOptions = facilities.map((f) => ({ label: f.name, value: f.facilityId }))
  const canSubmit = !!facilityId && !!startTime && !!endTime && endTime > startTime && !busy

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault()
    if (!canSubmit) return
    try {
      await run(() =>
        createFacilitySession({
          facilityId,
          startTime: new Date(startTime).toISOString(),
          endTime: new Date(endTime).toISOString(),
          capacity: capacity ? Number(capacity) : undefined,
        })
      )
      toast.success("Session scheduled")
      onOpenChange(false)
      onScheduled()
    } catch {
      // run() already toasted the real error; keep the dialog open for retry.
    }
  }

  return (
    <Dialog open={open} onOpenChange={onOpenChange} disablePointerDismissal>
      <DialogContent className="sm:max-w-md">
        <form onSubmit={handleSubmit} className="flex flex-col gap-4">
          <DialogHeader>
            <DialogTitle>Schedule Session</DialogTitle>
            <DialogDescription>Open a bookable time slot for a Scheduled-mode facility.</DialogDescription>
          </DialogHeader>

          <div className="flex flex-col gap-1.5">
            <Label>
              Facility <span className="text-destructive">*</span>
            </Label>
            <Select
              items={facilityOptions}
              value={facilityId}
              onValueChange={(v) => setFacilityId(v ?? "")}
            >
              <SelectTrigger className="w-full">
                <SelectValue placeholder="Select facility" />
              </SelectTrigger>
              <SelectContent>
                {facilityOptions.map((opt) => (
                  <SelectItem key={opt.value} value={opt.value}>
                    {opt.label}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          </div>

          <div className="grid grid-cols-2 gap-3">
            <div className="flex flex-col gap-1.5">
              <Label htmlFor="session-start">
                Start <span className="text-destructive">*</span>
              </Label>
              <Input
                id="session-start"
                type="datetime-local"
                value={startTime}
                onChange={(e) => setStartTime(e.target.value)}
                required
              />
            </div>
            <div className="flex flex-col gap-1.5">
              <Label htmlFor="session-end">
                End <span className="text-destructive">*</span>
              </Label>
              <Input
                id="session-end"
                type="datetime-local"
                value={endTime}
                onChange={(e) => setEndTime(e.target.value)}
                required
              />
            </div>
          </div>

          <div className="flex flex-col gap-1.5">
            <Label htmlFor="session-capacity">Capacity override</Label>
            <Input
              id="session-capacity"
              type="number"
              min={1}
              placeholder="Uses the facility's default capacity if left blank"
              value={capacity}
              onChange={(e) => setCapacity(e.target.value)}
            />
          </div>

          <DialogFooter>
            <Button type="button" variant="outline" onClick={() => onOpenChange(false)}>
              Cancel
            </Button>
            <Button type="submit" disabled={!canSubmit}>
              {busy && <Spinner className="size-4" />}
              Schedule Session
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  )
}

export { BookingsView }