import {
  closestCenter,
  DndContext,
  DragEndEvent,
  PointerSensor,
  useSensor,
  useSensors,
} from '@dnd-kit/core'
import { arrayMove, rectSortingStrategy, SortableContext, useSortable } from '@dnd-kit/sortable'
import { PermissionAction } from '@supabase/shared-types/out/constants'
import { keepPreviousData } from '@tanstack/react-query'
import { useParams } from 'common'
import dayjs from 'dayjs'
import { Plus, RefreshCw } from 'lucide-react'
import type { CSSProperties, DragEvent, ReactNode } from 'react'
import { useCallback, useEffect, useMemo, useState } from 'react'
import { toast } from 'sonner'
import { Button } from 'ui'
import { Row } from 'ui-patterns'

import { SnippetDropdown } from '@/components/interfaces/ProjectHome/SnippetDropdown'
import { ReportBlock } from '@/components/interfaces/Reports/ReportBlock/ReportBlock'
import { createSqlSnippetSkeletonV2 } from '@/components/interfaces/SQLEditor/SQLEditor.utils'
import type { ChartConfig } from '@/components/interfaces/SQLEditor/UtilityPanel/ChartConfig'
import { ButtonTooltip } from '@/components/ui/ButtonTooltip'
import { DEFAULT_CHART_CONFIG } from '@/components/ui/QueryBlock/QueryBlock'
import { AnalyticsInterval } from '@/data/analytics/constants'
import { useInvalidateAnalyticsQuery } from '@/data/analytics/utils'
import { useContentInfiniteQuery } from '@/data/content/content-infinite-query'
import { Content } from '@/data/content/content-query'
import {
  UpsertContentPayload,
  useContentUpsertMutation,
} from '@/data/content/content-upsert-mutation'
import { useAsyncCheckPermissions } from '@/hooks/misc/useCheckPermissions'
import { useSelectedProjectQuery } from '@/hooks/misc/useSelectedProject'
import { uuidv4 } from '@/lib/helpers'
import { useProfile } from '@/lib/profile'
import { useTrack } from '@/lib/telemetry/track'
import { useDatabaseSelectorStateSnapshot } from '@/state/database-selector'
import type { Dashboards } from '@/types'

export function CustomReportSection() {
  const startDate = dayjs().subtract(7, 'day').toISOString()
  const endDate = dayjs().toISOString()

  const { ref } = useParams()
  const { profile } = useProfile()
  const state = useDatabaseSelectorStateSnapshot()
  const track = useTrack()
  const { invalidateInfraMonitoringQuery } = useInvalidateAnalyticsQuery()
  const { data: project } = useSelectedProjectQuery()

  const [isRefreshing, setIsRefreshing] = useState<boolean>(false)

  const { data: reportsData } = useContentInfiniteQuery(
    { projectRef: ref, type: 'report', name: 'Home', limit: 1 },
    { placeholderData: keepPreviousData }
  )
  const homeReport = reportsData?.pages?.[0]?.content?.[0] as Content | undefined
  const reportContent = homeReport?.content as Dashboards.Content | undefined
  const [editableReport, setEditableReport] = useState<Dashboards.Content | undefined>(
    reportContent
  )
  const [isDraggingOver, setIsDraggingOver] = useState(false)

  const { can: canCreateReport } = useAsyncCheckPermissions(
    PermissionAction.CREATE,
    'user_content',
    { resource: { type: 'report', owner_id: profile?.id }, subject: { id: profile?.id } }
  )

  const { can: canUpdateReport } = useAsyncCheckPermissions(
    PermissionAction.UPDATE,
    'user_content',
    {
      resource: {
        type: 'report',
        visibility: homeReport?.visibility,
        owner_id: homeReport?.owner_id,
      },
      subject: { id: profile?.id },
    }
  )

  const { mutate: upsertContent } = useContentUpsertMutation()

  const persistReport = useCallback(
    (updated: Dashboards.Content) => {
      if (!ref || !homeReport) return
      upsertContent({ projectRef: ref, payload: { ...homeReport, content: updated } })
    },
    [homeReport, ref, upsertContent]
  )

  const sensors = useSensors(useSensor(PointerSensor, { activationConstraint: { distance: 8 } }))

  const handleDragStart = () => {}

  const recomputeSimpleGrid = useCallback(
    (layout: Dashboards.Chart[]) =>
      layout.map(
        (block, idx): Dashboards.Chart => ({
          ...block,
          x: idx % 2,
          y: Math.floor(idx / 2),
          w: 1,
          h: 1,
        })
      ),
    []
  )

  const handleDragEnd = useCallback(
    (event: DragEndEvent) => {
      const { active, over } = event
      if (!editableReport || !active || !over || active.id === over.id) return
      const items = editableReport.layout.map((x) => String(x.id))
      const oldIndex = items.indexOf(String(active.id))
      const newIndex = items.indexOf(String(over.id))
      if (oldIndex === -1 || newIndex === -1) return

      const moved = arrayMove(editableReport.layout, oldIndex, newIndex)
      const recomputed = recomputeSimpleGrid(moved)
      const updated = { ...editableReport, layout: recomputed }
      setEditableReport(updated)
      persistReport(updated)
    },
    [editableReport, persistReport, recomputeSimpleGrid]
  )

  const findNextPlacement = useCallback((current: Dashboards.Chart[]) => {
    const occupied = new Set(current.map((c) => `${c.y}-${c.x}`))
    let y = 0
    for (; ; y++) {
      const left = occupied.has(`${y}-0`)
      const right = occupied.has(`${y}-1`)
      if (!left || !right) {
        const x = left ? 1 : 0
        return { x, y }
      }
    }
  }, [])

  const createSnippetChartBlock = useCallback(
    (
      snippet: { id: string; name: string },
      position: { x: number; y: number }
    ): Dashboards.Chart => ({
      x: position.x,
      y: position.y,
      w: 1,
      h: 1,
      id: snippet.id,
      label: snippet.name,
      attribute: `snippet_${snippet.id}` as unknown as Dashboards.Chart['attribute'],
      provider: 'daily-stats',
      chart_type: 'bar',
      chartConfig: DEFAULT_CHART_CONFIG,
    }),
    []
  )

  const addSnippetToReport = useCallback(
    (snippet: { id: string; name: string }) => {
      if (
        editableReport?.layout?.some(
          (x) =>
            String(x.id) === String(snippet.id) || String(x.attribute) === `snippet_${snippet.id}`
        )
      ) {
        toast('This block is already in your report')
        return
      }
      // If the Home report doesn't exist yet, create it with the new block
      if (!editableReport || !homeReport) {
        if (!ref || !profile) return

        // Initial placement for first block
        const initialBlock = createSnippetChartBlock(snippet, { x: 0, y: 0 })

        const newReport: Dashboards.Content = {
          schema_version: 1,
          period_start: { time_period: '7d', date: '' },
          period_end: { time_period: 'today', date: '' },
          interval: '1d',
          layout: [initialBlock],
        }

        setEditableReport(newReport)
        upsertContent({
          projectRef: ref,
          payload: {
            id: uuidv4(),
            type: 'report',
            name: 'Home',
            description: '',
            visibility: 'project',
            owner_id: profile.id,
            content: newReport,
          },
        })

        track('home_custom_report_block_added', { block_id: snippet.id, position: 0 })
        return
      }
      const current = [...editableReport.layout]
      const { x, y } = findNextPlacement(current)
      current.push(createSnippetChartBlock(snippet, { x, y }))
      const updated = { ...editableReport, layout: current }
      setEditableReport(updated)
      persistReport(updated)

      track('home_custom_report_block_added', {
        block_id: snippet.id,
        position: current.length - 1,
      })
    },
    [
      editableReport,
      homeReport,
      ref,
      profile,
      upsertContent,
      track,
      findNextPlacement,
      createSnippetChartBlock,
      persistReport,
    ]
  )

  const handleRemoveChart = ({ metric }: { metric: { key: string } }) => {
    if (!editableReport) return
    const removedChart = editableReport.layout.find(
      (x) => x.attribute === (metric.key as unknown as Dashboards.Chart['attribute'])
    )
    const nextLayout = editableReport.layout.filter(
      (x) => x.attribute !== (metric.key as unknown as Dashboards.Chart['attribute'])
    )
    const updated = { ...editableReport, layout: nextLayout }
    setEditableReport(updated)
    persistReport(updated)

    if (removedChart) {
      track('home_custom_report_block_removed', { block_id: String(removedChart.id) })
    }
  }

  const handleUpdateChart = (
    id: string,
    {
      chart,
      chartConfig,
    }: { chart?: Partial<Dashboards.Chart>; chartConfig?: Partial<ChartConfig> }
  ) => {
    if (!editableReport) return
    const currentChart = editableReport.layout.find((x) => x.id === id)
    if (!currentChart) return
    const updatedChart: Dashboards.Chart = { ...currentChart, ...(chart ?? {}) }
    if (chartConfig) {
      updatedChart.chartConfig = { ...(currentChart.chartConfig ?? {}), ...chartConfig }
    }
    const updatedLayouts = editableReport.layout.map((x) => (x.id === id ? updatedChart : x))
    const updated = { ...editableReport, layout: updatedLayouts }
    setEditableReport(updated)
    persistReport(updated)
  }

  const handleDrop = useCallback(
    async (e: DragEvent<HTMLDivElement>) => {
      e.preventDefault()
      setIsDraggingOver(false)
      if (!ref || !profile || !project) return

      const data = e.dataTransfer.getData('application/json')
      if (!data) return

      const { label, sql } = JSON.parse(data)
      if (!label || !sql) return

      const toastId = toast.loading(`Creating new query: ${label}`)

      const payload = createSqlSnippetSkeletonV2({
        name: label,
        sql,
        owner_id: profile.id,
        project_id: project.id,
      }) as UpsertContentPayload

      upsertContent({ projectRef: ref, payload })

      // Handle success optimistically
      toast.success(`Successfully created new query: ${label}`, { id: toastId })
      addSnippetToReport({ id: payload.id, name: label })
      track('custom_report_assistant_sql_block_added')
    },
    [ref, profile, project, upsertContent, addSnippetToReport, track]
  )

  const handleDragOver = (e: DragEvent<HTMLDivElement>) => {
    setIsDraggingOver(true)
    e.preventDefault()
  }

  const handleDragLeave = () => {
    setIsDraggingOver(false)
  }

  const onRefreshReport = () => {
    if (!ref) return

    setIsRefreshing(true)
    const monitoringCharts = editableReport?.layout.filter(
      (x) => x.provider === 'infra-monitoring' || x.provider === 'daily-stats'
    )
    monitoringCharts?.forEach((x) => {
      invalidateInfraMonitoringQuery(ref, {
        attribute: x.attribute,
        startDate,
        endDate,
        interval: editableReport?.interval || '1d',
        databaseIdentifier: state.selectedDatabaseId,
      })
    })
    setTimeout(() => setIsRefreshing(false), 1000)
  }

  const layout = useMemo(() => editableReport?.layout ?? [], [editableReport])

  useEffect(() => {
    if (reportContent) setEditableReport(reportContent)
  }, [reportContent])

  return (
    <div className="space-y-6">
      <div className="flex items-center justify-between">
        <h3 className="heading-section">Reports</h3>
        <div className="flex items-center gap-x-2">
          {layout.length > 0 && (
            <ButtonTooltip
              type="default"
              icon={<RefreshCw className={isRefreshing ? 'animate-spin' : ''} />}
              className="w-7"
              disabled={isRefreshing}
              tooltip={{ content: { side: 'bottom', text: 'Refresh report' } }}
              onClick={onRefreshReport}
            />
          )}
          {canUpdateReport || canCreateReport ? (
            <SnippetDropdown
              projectRef={ref}
              onSelect={addSnippetToReport}
              trigger={
                <Button type="default" icon={<Plus />}>
                  Add block
                </Button>
              }
              side="bottom"
              align="end"
              autoFocus
            />
          ) : null}
        </div>
      </div>
      <div className="relative">
        {isDraggingOver && (
          <div className="absolute inset-0 rounded-sm bg-brand/10 pointer-events-none z-10" />
        )}
        {layout.length === 0 ? (
          <div
            className="h-64 flex flex-col items-center justify-center rounded-sm border-2 border-dashed p-16 transition-colors"
            onDrop={handleDrop}
            onDragOver={handleDragOver}
            onDragLeave={handleDragLeave}
          >
            <h4>Build a custom report</h4>
            <p className="text-sm text-foreground-light mb-4">
              Keep track of your most important metrics
            </p>
            {canUpdateReport || canCreateReport ? (
              <SnippetDropdown
                projectRef={ref}
                onSelect={addSnippetToReport}
                trigger={
                  <Button type="default" iconRight={<Plus size={14} />}>
                    Add your first block
                  </Button>
                }
                side="bottom"
                align="center"
                autoFocus
              />
            ) : (
              <p className="text-sm text-foreground-light">No charts set up yet in report</p>
            )}
          </div>
        ) : (
          <DndContext
            sensors={sensors}
            collisionDetection={closestCenter}
            onDragStart={handleDragStart}
            onDragEnd={handleDragEnd}
          >
            <SortableContext
              items={(editableReport?.layout ?? []).map((x) => String(x.id))}
              strategy={rectSortingStrategy}
            >
              <Row
                maxColumns={4}
                minWidth={280}
                onDrop={handleDrop}
                onDragOver={handleDragOver}
                onDragLeave={handleDragLeave}
              >
                {layout.map((item) => (
                  <SortableReportBlock key={item.id} id={String(item.id)}>
                    <div className="h-64">
                      <ReportBlock
                        key={item.id}
                        item={item}
                        startDate={startDate}
                        endDate={endDate}
                        interval={
                          (editableReport?.interval as AnalyticsInterval) ??
                          ('1d' as AnalyticsInterval)
                        }
                        disableUpdate={false}
                        isRefreshing={isRefreshing}
                        onRemoveChart={handleRemoveChart}
                        onUpdateChart={(config) => handleUpdateChart(item.id, config)}
                      />
                    </div>
                  </SortableReportBlock>
                ))}
              </Row>
            </SortableContext>
          </DndContext>
        )}
      </div>
    </div>
  )
}

function SortableReportBlock({ id, children }: { id: string; children: ReactNode }) {
  const { attributes, listeners, setNodeRef, transform, transition, isDragging } = useSortable({
    id,
  })

  const style: CSSProperties = {
    transform: transform
      ? `translate3d(${Math.round(transform.x)}px, ${Math.round(transform.y)}px, 0)`
      : undefined,
    transition,
  }

  return (
    <div
      ref={setNodeRef}
      style={style}
      className={isDragging ? 'opacity-70 will-change-transform' : 'will-change-transform'}
      {...attributes}
      {...(listeners ?? {})}
    >
      {children}
    </div>
  )
}