import type { PostgresSchema, PostgresTable } from '@supabase/postgres-meta'
import { PermissionAction } from '@supabase/shared-types/out/constants'
import { toPng, toSvg } from 'html-to-image'
import { Check, Copy, Download, Loader2, Plus } from 'lucide-react'
import { useTheme } from 'next-themes'
import Link from 'next/link'
import { useEffect, useMemo, useRef, useState } from 'react'
import ReactFlow, { Background, BackgroundVariant, MiniMap, useReactFlow } from 'reactflow'

import 'reactflow/dist/style.css'

import { LOCAL_STORAGE_KEYS, useParams } from 'common'
import AlertError from 'components/ui/AlertError'
import { ButtonTooltip } from 'components/ui/ButtonTooltip'
import SchemaSelector from 'components/ui/SchemaSelector'
import { useSchemasQuery } from 'data/database/schemas-query'
import { useTablesQuery } from 'data/tables/tables-query'
import { useAsyncCheckPermissions } from 'hooks/misc/useCheckPermissions'
import { useLocalStorage } from 'hooks/misc/useLocalStorage'
import { useQuerySchemaState } from 'hooks/misc/useSchemaQueryState'
import { useSelectedProjectQuery } from 'hooks/misc/useSelectedProject'
import { useIsProtectedSchema } from 'hooks/useProtectedSchemas'
import { tablesToSQL } from 'lib/helpers'
import { toast } from 'sonner'
import { useTableEditorStateSnapshot } from 'state/table-editor'
import {
  Button,
  copyToClipboard,
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from 'ui'
import { Admonition } from 'ui-patterns/admonition'

import { SidePanelEditor } from '../../TableGridEditor/SidePanelEditor/SidePanelEditor'
import { ColumnEditionContextProvider, ColumnEditionContextType } from './ColumnEditionContext'
import { SchemaGraphLegend } from './SchemaGraphLegend'
import { getGraphDataFromTables, getLayoutedElementsViaDagre } from './Schemas.utils'
import { TableNode } from './SchemaTableNode'

// [Joshen] Persisting logic: Only save positions to local storage WHEN a node is moved OR when explicitly clicked to reset layout

export const SchemaGraph = () => {
  const { ref } = useParams()
  const { resolvedTheme } = useTheme()
  const { data: project } = useSelectedProjectQuery()
  const { selectedSchema, setSelectedSchema } = useQuerySchemaState()
  const [selectedTable, setSelectedTable] = useState<PostgresTable | null>(null)
  const snap = useTableEditorStateSnapshot()

  const [copied, setCopied] = useState(false)
  useEffect(() => {
    if (copied) {
      setTimeout(() => setCopied(false), 2000)
    }
  }, [copied])

  const [isDownloading, setIsDownloading] = useState(false)

  const miniMapNodeColor = '#111318'
  const miniMapMaskColor = resolvedTheme?.includes('dark')
    ? 'rgb(17, 19, 24, .8)'
    : 'rgb(237, 237, 237, .8)'

  const reactFlowInstance = useReactFlow()
  const nodeTypes = useMemo(
    () => ({
      table: TableNode,
    }),
    []
  )

  const {
    data: schemas,
    error: errorSchemas,
    isSuccess: isSuccessSchemas,
    isPending: isLoadingSchemas,
    isError: isErrorSchemas,
  } = useSchemasQuery({
    projectRef: project?.ref,
    connectionString: project?.connectionString,
  })

  const {
    data: tables = [],
    error: errorTables,
    isSuccess: isSuccessTables,
    isPending: isLoadingTables,
    isError: isErrorTables,
  } = useTablesQuery({
    projectRef: project?.ref,
    connectionString: project?.connectionString,
    schema: selectedSchema,
    includeColumns: true,
  })
  const hasNoTables = isSuccessSchemas && tables.length === 0

  const schema = (schemas ?? []).find((s) => s.name === selectedSchema)
  const [, setStoredPositions] = useLocalStorage(
    LOCAL_STORAGE_KEYS.SCHEMA_VISUALIZER_POSITIONS(ref as string, schema?.id ?? 0),
    {}
  )

  const { can: canUpdateTables } = useAsyncCheckPermissions(
    PermissionAction.TENANT_SQL_ADMIN_WRITE,
    'tables'
  )

  const { isSchemaLocked } = useIsProtectedSchema({ schema: selectedSchema })

  const canAddTables = canUpdateTables && !isSchemaLocked

  const resetLayout = () => {
    const nodes = reactFlowInstance.getNodes()
    const edges = reactFlowInstance.getEdges()

    getLayoutedElementsViaDagre(nodes, edges)
    reactFlowInstance.setNodes(nodes)
    reactFlowInstance.setEdges(edges)
    setTimeout(() => reactFlowInstance.fitView({}))
    saveNodePositions()
  }

  const saveNodePositions = () => {
    if (schema === undefined) return console.error('Schema is required')

    const nodes = reactFlowInstance.getNodes()
    if (nodes.length > 0) {
      const nodesPositionData = nodes.reduce((a, b) => {
        return { ...a, [b.id]: b.position }
      }, {})
      setStoredPositions(nodesPositionData)
    }
  }

  const downloadImage = (format: 'png' | 'svg') => {
    const reactflowViewport = document.querySelector('.react-flow__viewport') as HTMLElement
    if (!reactflowViewport) return

    setIsDownloading(true)
    const width = reactflowViewport.clientWidth
    const height = reactflowViewport.clientHeight
    const { x, y, zoom } = reactFlowInstance.getViewport()

    if (format === 'svg') {
      toSvg(reactflowViewport, {
        backgroundColor: 'white',
        width,
        height,
        style: {
          width: width.toString(),
          height: height.toString(),
          transform: `translate(${x}px, ${y}px) scale(${zoom})`,
        },
      })
        .then((data) => {
          const a = document.createElement('a')
          a.setAttribute('download', `supabase-schema-${ref}.svg`)
          a.setAttribute('href', data)
          a.click()
          toast.success('Successfully downloaded as SVG')
        })
        .catch((error) => {
          console.error('Failed to download:', error)
          toast.error('Failed to download current view:', error.message)
        })
        .finally(() => {
          setIsDownloading(false)
        })
    } else if (format === 'png') {
      toPng(reactflowViewport, {
        backgroundColor: 'white',
        width,
        height,
        style: {
          width: width.toString(),
          height: height.toString(),
          transform: `translate(${x}px, ${y}px) scale(${zoom})`,
        },
      })
        .then((data) => {
          const a = document.createElement('a')
          a.setAttribute('download', `supabase-schema-${ref}.png`)
          a.setAttribute('href', data)
          a.click()
          toast.success('Successfully downloaded as PNG')
        })
        .catch((error) => {
          console.error('Failed to download:', error)
          toast.error('Failed to download current view:', error.message)
        })
        .finally(() => {
          setIsDownloading(false)
        })
    }
  }

  const isFirstLoad = useRef(true)
  useEffect(() => {
    if (isSuccessTables && isSuccessSchemas && tables.length > 0) {
      const schema = schemas.find((s) => s.name === selectedSchema) as PostgresSchema
      getGraphDataFromTables(ref as string, schema, tables).then(({ nodes, edges }) => {
        reactFlowInstance.setNodes(nodes)
        reactFlowInstance.setEdges(edges)
        // Prevent resetting a view after first load to avoid layout changes after editing a column
        if (isFirstLoad.current) {
          isFirstLoad.current = false
          setTimeout(() => reactFlowInstance.fitView({})) // it needs to happen during next event tick
        }
      })
    }
  }, [isSuccessTables, isSuccessSchemas, tables, resolvedTheme])

  const columnEditionContext = useMemo<ColumnEditionContextType>(
    () => ({
      onEditColumn: (tableId, columnId) => {
        const table = tables.find((table) => table.id === tableId)
        if (!table || table.columns == null) return

        const column = table.columns.find((column) => column.id === columnId)
        if (!column) return

        setSelectedTable(table)
        snap.onEditColumn(column)
      },
    }),
    [tables, snap]
  )

  return (
    <>
      <div className="flex items-center justify-between p-4 border-b border-muted h-[var(--header-height)]">
        {isLoadingSchemas && (
          <div className="h-[34px] w-[260px] bg-foreground-lighter rounded shimmering-loader" />
        )}

        {isErrorSchemas && (
          <AlertError error={errorSchemas as any} subject="Failed to retrieve schemas" />
        )}

        {isSuccessSchemas && (
          <>
            <SchemaSelector
              className="w-[180px]"
              size="tiny"
              showError={false}
              selectedSchemaName={selectedSchema}
              onSelectSchema={setSelectedSchema}
            />
            {!hasNoTables && (
              <div className="flex items-center gap-x-2">
                <ButtonTooltip
                  type="outline"
                  icon={copied ? <Check data-testid="copy-sql-ready" /> : <Copy />}
                  onClick={() => {
                    if (tables) {
                      copyToClipboard(tablesToSQL(tables))
                      setCopied(true)
                    }
                  }}
                  tooltip={{
                    content: {
                      side: 'bottom',
                      text: (
                        <div className="max-w-[180px] space-y-2 text-foreground-light">
                          <p className="text-foreground">Note</p>
                          <p>
                            This schema is for context or debugging only. Table order and
                            constraints may be invalid. Not meant to be run as-is.
                          </p>
                        </div>
                      ),
                    },
                  }}
                >
                  Copy as SQL
                </ButtonTooltip>
                <DropdownMenu>
                  <DropdownMenuTrigger asChild>
                    <ButtonTooltip
                      aria-label="Download Schema"
                      type="default"
                      loading={isDownloading}
                      className="px-1.5"
                      icon={<Download />}
                      tooltip={{ content: { side: 'bottom', text: 'Download current view' } }}
                    />
                  </DropdownMenuTrigger>
                  <DropdownMenuContent className="w-32">
                    <DropdownMenuItem onClick={() => downloadImage('png')}>
                      Download as PNG
                    </DropdownMenuItem>
                    <DropdownMenuItem onClick={() => downloadImage('svg')}>
                      Download as SVG
                    </DropdownMenuItem>
                  </DropdownMenuContent>
                </DropdownMenu>
                <ButtonTooltip
                  type="default"
                  onClick={resetLayout}
                  tooltip={{
                    content: {
                      side: 'bottom',
                      text: 'Automatically arrange the layout of all nodes',
                    },
                  }}
                >
                  Auto layout
                </ButtonTooltip>
              </div>
            )}
          </>
        )}
      </div>
      {isLoadingTables && (
        <div className="w-full h-full flex items-center justify-center gap-x-2">
          <Loader2 className="animate-spin text-foreground-light" size={16} />
          <p className="text-sm text-foreground-light">Loading tables</p>
        </div>
      )}
      {isErrorTables && (
        <div className="w-full h-full flex items-center justify-center px-20">
          <AlertError subject="Failed to retrieve tables" error={errorTables} />
        </div>
      )}
      {isSuccessTables && (
        <>
          {hasNoTables ? (
            <div className="flex items-center justify-center w-full h-full">
              <Admonition
                type="default"
                className="max-w-md"
                title="No tables in schema"
                description={
                  isSchemaLocked
                    ? `The “${selectedSchema}” schema is managed by Supabase and is read-only through
                    the dashboard.`
                    : !canUpdateTables
                      ? 'You need additional permissions to create tables'
                      : `The “${selectedSchema}” schema doesn’t have any tables.`
                }
              >
                {canAddTables && (
                  <Button asChild className="mt-2" type="default" icon={<Plus />}>
                    <Link href={`/project/${ref}/editor?create=table`}>New table</Link>
                  </Button>
                )}
              </Admonition>
            </div>
          ) : (
            <ColumnEditionContextProvider value={columnEditionContext}>
              <div className="w-full h-full">
                <ReactFlow
                  defaultNodes={[]}
                  defaultEdges={[]}
                  defaultEdgeOptions={{
                    type: 'smoothstep',
                    animated: true,
                    deletable: false,
                  }}
                  nodeTypes={nodeTypes}
                  fitView
                  minZoom={0.8}
                  maxZoom={1.8}
                  proOptions={{ hideAttribution: true }}
                  onNodeDragStop={() => saveNodePositions()}
                >
                  <Background
                    gap={16}
                    className="[&>*]:stroke-foreground-muted opacity-[25%]"
                    variant={BackgroundVariant.Dots}
                    color={'inherit'}
                  />
                  <MiniMap
                    pannable
                    zoomable
                    nodeColor={miniMapNodeColor}
                    maskColor={miniMapMaskColor}
                    className="border rounded-md shadow-sm"
                  />
                  <SchemaGraphLegend />
                </ReactFlow>
              </div>
            </ColumnEditionContextProvider>
          )}
        </>
      )}
      <SidePanelEditor selectedTable={selectedTable ?? undefined} includeColumns />
    </>
  )
}