import { useEffect, useMemo, useState } from 'react'
import type { ReactNode } from 'react'
import { Alert, Button, Card, Empty, Grid, Input, Message, Modal, Space, Spin, Switch, Typography } from '@arco-design/web-react'
import {
  IconBook,
  IconCheckCircle,
  IconCompass,
  IconDelete,
  IconEdit,
  IconLaunch,
  IconLink,
  IconRefresh,
  IconStar,
  IconStorage,
} from '@arco-design/web-react/icon'
import type {
  DatasetDepositDTO,
  DatasetItemDTO,
  DatasetItemPageDTO,
  DatasetItemUpdate,
  DatasetSourceDTO,
  DatasetSourceInput,
  DatasetSourceKind,
  DatasetSyncResultDTO,
} from '../api/dataset'

const { Row, Col } = Grid
const { Title, Text, Paragraph } = Typography
const { TextArea } = Input
const ITEM_PAGE_SIZE = 50

type DataSourceCard = DatasetSourceDTO & {
  icon: ReactNode
  color: string
}

type SourceDraft = {
  name: string
  kind: DatasetSourceKind
  url: string
  iconUrl: string
  description: string
  enabled: boolean
}

const EMPTY_SOURCE_DRAFT: SourceDraft = {
  name: '',
  kind: 'rss',
  url: '',
  iconUrl: '',
  description: '',
  enabled: true,
}

export function WorkspaceExplorePage({
  activeProjectID,
  activeProjectName,
  onListSources,
  onListItems,
  onCreateSource,
  onUpdateSource,
  onDeleteSource,
  onUpdateItem,
  onSyncSources,
  onDepositItem,
}: {
  activeProjectID: string
  activeProjectName: string
  onListSources: (signal?: AbortSignal) => Promise<DatasetSourceDTO[]>
  onListItems: (sourceId?: string, offset?: number, limit?: number, signal?: AbortSignal) => Promise<DatasetItemPageDTO>
  onCreateSource: (input: DatasetSourceInput) => Promise<DatasetSourceDTO>
  onUpdateSource: (sourceId: string, input: DatasetSourceInput) => Promise<DatasetSourceDTO>
  onDeleteSource: (sourceId: string) => Promise<void>
  onUpdateItem: (itemId: string, input: DatasetItemUpdate) => Promise<DatasetItemDTO>
  onSyncSources: () => Promise<DatasetSyncResultDTO[]>
  onDepositItem: (itemId: string, projectId: string) => Promise<DatasetDepositDTO & { refreshFailed?: boolean }>
}) {
  const [sourceRecords, setSourceRecords] = useState<DatasetSourceDTO[]>([])
  const [items, setItems] = useState<DatasetItemDTO[]>([])
  const [itemTotal, setItemTotal] = useState(0)
  const [activeSourceID, setActiveSourceID] = useState('all')
  const [activeItemID, setActiveItemID] = useState<string | null>(null)
  const [sourceModalMode, setSourceModalMode] = useState<'add' | 'edit' | null>(null)
  const [editingSourceID, setEditingSourceID] = useState<string | null>(null)
  const [sourceDraft, setSourceDraft] = useState<SourceDraft>(EMPTY_SOURCE_DRAFT)
  const [sourceError, setSourceError] = useState('')
  const [loadError, setLoadError] = useState('')
  const [loading, setLoading] = useState(true)
  const [itemsLoading, setItemsLoading] = useState(true)
  const [saving, setSaving] = useState(false)
  const [syncing, setSyncing] = useState(false)
  const [depositingItemID, setDepositingItemID] = useState<string | null>(null)

  useEffect(() => {
    const controller = new AbortController()
    setLoading(true)
    setLoadError('')
    onListSources(controller.signal)
      .then((nextSources) => {
        setSourceRecords(nextSources)
      })
      .catch((error: unknown) => {
        if (!controller.signal.aborted) {
          setLoadError(error instanceof Error ? error.message : '探索数据加载失败')
        }
      })
      .finally(() => {
        if (!controller.signal.aborted) setLoading(false)
      })
    return () => controller.abort()
  }, [onListSources])

  useEffect(() => {
    const controller = new AbortController()
    setItemsLoading(true)
    setLoadError('')
    setItems([])
    setItemTotal(0)
    setActiveItemID(null)
    const sourceID = activeSourceID === 'all' ? undefined : activeSourceID
    onListItems(sourceID, 0, ITEM_PAGE_SIZE, controller.signal)
      .then((page) => {
        setItems(page.items)
        setItemTotal(page.total)
      })
      .catch((error: unknown) => {
        if (!controller.signal.aborted) {
          setLoadError(error instanceof Error ? error.message : '探索内容加载失败')
        }
      })
      .finally(() => {
        if (!controller.signal.aborted) setItemsLoading(false)
      })
    return () => controller.abort()
  }, [activeSourceID, onListItems])

  const sources = useMemo<DataSourceCard[]>(() => {
    const allSource: DataSourceCard = {
      id: 'all',
      name: '全部',
      kind: 'manual',
      url: '',
      iconUrl: '',
      description: '全部探索内容',
      enabled: true,
      builtIn: true,
      lastSyncedAt: null,
      itemCount: sourceRecords.reduce((total, source) => total + source.itemCount, 0),
      createdAt: '',
      updatedAt: '',
      icon: <IconStorage />,
      color: 'blue',
    }
    return [
      allSource,
      ...sourceRecords.map((source) => ({
        ...source,
        icon: source.iconUrl
          ? <img className="explore-source-image" src={source.iconUrl} alt="" />
          : sourceIcon(source.kind),
        color: sourceColor(source.kind),
      })),
    ]
  }, [sourceRecords])

  const filteredItems = items

  useEffect(() => {
    if (filteredItems.length === 0) {
      setActiveItemID(null)
      return
    }
    if (!activeItemID || !filteredItems.some((item) => item.id === activeItemID)) {
      setActiveItemID(filteredItems[0].id)
    }
  }, [activeItemID, filteredItems])

  const selected = filteredItems.find((item) => item.id === activeItemID) ?? filteredItems[0]
  const activeSource = sourceByID(sources, activeSourceID)
  const selectedSource = selected ? sourceByID(sources, selected.sourceId) : activeSource
  const editingSource = editingSourceID
    ? sourceRecords.find((source) => source.id === editingSourceID)
    : undefined

  function openAddSource() {
    setEditingSourceID(null)
    setSourceDraft(EMPTY_SOURCE_DRAFT)
    setSourceError('')
    setSourceModalMode('add')
  }

  function openEditSource(source: DataSourceCard) {
    setEditingSourceID(source.id)
    setSourceDraft({
      name: source.name,
      kind: source.kind,
      url: source.url,
      iconUrl: source.iconUrl,
      description: source.description,
      enabled: source.enabled,
    })
    setSourceError('')
    setSourceModalMode('edit')
  }

  async function saveSource() {
    const input: DatasetSourceInput = {
      name: sourceDraft.name.trim(),
      kind: sourceDraft.kind,
      url: sourceDraft.url.trim(),
      iconUrl: sourceDraft.iconUrl.trim(),
      description: sourceDraft.description.trim(),
      enabled: sourceDraft.enabled,
    }
    if (!input.name) {
      setSourceError('请输入数据源名称')
      return
    }
    if (input.kind === 'rss' && !input.url) {
      setSourceError('RSS 数据源必须填写地址')
      return
    }
    setSaving(true)
    setSourceError('')
    try {
      if (sourceModalMode === 'edit' && editingSourceID) {
        const updated = await onUpdateSource(editingSourceID, input)
        setSourceRecords((current) => current.map((source) => source.id === updated.id ? updated : source))
        Message.success('数据源已更新')
      } else {
        const created = await onCreateSource(input)
        setSourceRecords((current) => [...current, created])
        Message.success('数据源已添加')
      }
      setSourceModalMode(null)
    } catch (error) {
      setSourceError(error instanceof Error ? error.message : '数据源保存失败')
    } finally {
      setSaving(false)
    }
  }

  function deleteSource(source: DataSourceCard) {
    Modal.confirm({
      title: `删除“${source.name}”数据源？`,
      content: '删除后，该数据源及其采集条目和待执行任务都会移除。',
      okButtonProps: { status: 'danger' },
      onOk: async () => {
        try {
          await onDeleteSource(source.id)
          setSourceRecords((current) => current.filter((item) => item.id !== source.id))
          setItems((current) => current.filter((item) => item.sourceId !== source.id))
          if (activeSourceID === source.id) setActiveSourceID('all')
          Message.success('数据源已删除')
        } catch (error) {
          Message.error(error instanceof Error ? error.message : '数据源删除失败')
          throw error
        }
      },
    })
  }

  async function syncSources() {
    setSyncing(true)
    try {
      const results = await onSyncSources()
      if (results.length === 0) {
        Message.info('暂无已启用的 RSS 数据源')
      } else {
        const sourceID = activeSourceID === 'all' ? undefined : activeSourceID
        const [nextSources, nextPage] = await Promise.all([
          onListSources(),
          onListItems(sourceID, 0, ITEM_PAGE_SIZE),
        ])
        setSourceRecords(nextSources)
        setItems(nextPage.items)
        setItemTotal(nextPage.total)
        const failed = results.filter((result) => result.status === 'failed').length
        if (failed > 0) {
          Message.warning(`${results.length - failed} 个数据源采集完成，${failed} 个失败`)
        } else {
          Message.success(`已完成 ${results.length} 个数据源采集任务`)
        }
      }
    } catch (error) {
      Message.error(error instanceof Error ? error.message : '数据源采集失败')
    } finally {
      setSyncing(false)
    }
  }

  async function loadMoreItems() {
    if (itemsLoading || items.length >= itemTotal) return
    setItemsLoading(true)
    try {
      const sourceID = activeSourceID === 'all' ? undefined : activeSourceID
      const page = await onListItems(sourceID, items.length, ITEM_PAGE_SIZE)
      setItems((current) => [...current, ...page.items])
      setItemTotal(page.total)
    } catch (error) {
      Message.error(error instanceof Error ? error.message : '更多探索内容加载失败')
    } finally {
      setItemsLoading(false)
    }
  }

  async function updateSelected(input: DatasetItemUpdate) {
    if (!selected) return
    try {
      const updated = await onUpdateItem(selected.id, input)
      setItems((current) => current.map((item) => item.id === updated.id ? updated : item))
    } catch (error) {
      Message.error(error instanceof Error ? error.message : '数据条目更新失败')
    }
  }

  async function depositSelected() {
    if (!selected || !activeProjectID) return
    setDepositingItemID(selected.id)
    try {
      const result = await onDepositItem(selected.id, activeProjectID)
      if (result.refreshFailed) {
        Message.warning(`笔记已沉淀到项目“${activeProjectName}”，但项目数据刷新失败`)
      } else {
        Message.success(`已沉淀到项目“${activeProjectName}”的笔记资料`)
      }
    } catch (error) {
      Message.error(error instanceof Error ? error.message : '沉淀到项目失败')
    } finally {
      setDepositingItemID(null)
    }
  }

  return (
    <div className="workspace-explore-page overview-page">
      <div className="overview-head">
        <div>
          <Title heading={4}>探索</Title>
          <Text type="secondary">多个外部数据源的集中阅读页，采集文章并沉淀到项目。</Text>
        </div>
        <Space>
          <Button icon={<IconRefresh />} loading={syncing} onClick={() => void syncSources()}>同步数据源</Button>
          <Button type="primary" icon={<IconLink />} onClick={openAddSource}>添加数据源</Button>
        </Space>
      </div>

      {loadError ? <Alert type="error" content={loadError} /> : null}

      <Spin loading={loading || (itemsLoading && items.length === 0)} style={{ width: '100%' }}>
        <Row gutter={10} className="explore-source-row">
          {sources.map((source) => (
            <Col span={6} key={source.id}>
              <Card
                className={activeSourceID === source.id ? 'compact-card explore-source-card active' : 'compact-card explore-source-card'}
                bordered
                onClick={() => setActiveSourceID(source.id)}
              >
                <span className={`explore-source-icon ${source.color}`}>{source.icon}</span>
                <span className="explore-source-copy">
                  <Text className="explore-source-name">{source.name}</Text>
                  <Text type="secondary">{sourceSubtitle(source)}</Text>
                </span>
                {source.id !== 'all' ? (
                  <span className="explore-source-actions" onClick={(event) => event.stopPropagation()}>
                    <Button aria-label={`编辑${source.name}`} type="text" size="mini" icon={<IconEdit />} onClick={() => openEditSource(source)} />
                    {!source.builtIn ? (
                      <Button aria-label={`删除${source.name}`} type="text" size="mini" status="danger" icon={<IconDelete />} onClick={() => deleteSource(source)} />
                    ) : null}
                  </span>
                ) : null}
              </Card>
            </Col>
          ))}
        </Row>

        {selected ? (
          <section className="explore-reader-layout">
            <Card className="explore-article-list queue-section" bordered>
              <div className="explore-list-header">
                <Title heading={5}>
                  <Space size={6}>
                    <span className={`explore-source-icon mini ${activeSource.color}`}>{activeSource.icon}</span>
                    <span>{activeSource.name}</span>
                  </Space>
                </Title>
                <Button type="text" icon={<IconRefresh />} loading={syncing} onClick={() => void syncSources()} />
              </div>
              <div className="explore-list-body">
                {filteredItems.map((item) => {
                  const itemSource = sourceByID(sources, item.sourceId)
                  return (
                    <button
                      key={item.id}
                      className={item.id === selected.id ? 'explore-article-item active' : 'explore-article-item'}
                      onClick={() => setActiveItemID(item.id)}
                    >
                      <span className={`explore-source-logo ${itemSource.color}`}>{sourceInitial(itemSource.name)}</span>
                      <span className="explore-article-copy">
                        <Text type="secondary">{itemSource.name} · {itemTime(item)}</Text>
                        <Text className="explore-article-title">{item.title}</Text>
                        <Text className="explore-article-summary" type="secondary" ellipsis={{ showTooltip: true }}>
                          {item.summary || '暂无摘要'}
                        </Text>
                      </span>
                    </button>
                  )
                })}
                {items.length < itemTotal ? (
                  <Button long type="text" loading={itemsLoading} onClick={() => void loadMoreItems()}>
                    加载更多（{items.length}/{itemTotal}）
                  </Button>
                ) : null}
              </div>
            </Card>

            <Card className="explore-article-detail queue-section" bordered>
              <div className="explore-detail-toolbar">
                <Title heading={5}>{selected.title}</Title>
                <Space>
                  <Button
                    aria-label={selected.status === 'read' ? '标记未读' : '标记已读'}
                    type={selected.status === 'read' ? 'primary' : 'text'}
                    icon={<IconCheckCircle />}
                    onClick={() => void updateSelected({ status: selected.status === 'read' ? 'unread' : 'read', starred: selected.starred })}
                  />
                  <Button
                    aria-label={selected.starred ? '取消收藏' : '收藏'}
                    type={selected.starred ? 'primary' : 'text'}
                    icon={<IconStar />}
                    onClick={() => void updateSelected({ status: selected.status, starred: !selected.starred })}
                  />
                  <Button
                    aria-label={`沉淀到项目${activeProjectName}`}
                    type="text"
                    icon={<IconBook />}
                    loading={depositingItemID === selected.id}
                    onClick={() => void depositSelected()}
                  />
                  {selected.url ? <Button type="text" icon={<IconLaunch />} href={selected.url} target="_blank" /> : null}
                </Space>
              </div>
              <article className="explore-article-body">
                <Space className="explore-article-meta" wrap>
                  <span className={`explore-source-logo small ${selectedSource.color}`}>{sourceInitial(selectedSource.name)}</span>
                  <Text type="secondary">{selectedSource.name}</Text>
                  <Text type="secondary">{itemTime(selected)}</Text>
                </Space>
                {selected.imageUrl ? (
                  <img className="explore-article-image" src={selected.imageUrl} alt="" />
                ) : null}
                <Paragraph className="explore-article-content">{selected.content || selected.summary || '暂无正文'}</Paragraph>
              </article>
            </Card>
          </section>
        ) : (
          <Card className="queue-section" bordered>
            <Empty description={sourceRecords.length === 0 ? '暂无数据源，请先添加数据源' : '暂无数据源文章'} />
          </Card>
        )}
      </Spin>

      <Modal
        className="explore-source-modal"
        title={sourceModalMode === 'edit' ? '编辑数据源' : '添加数据源'}
        visible={sourceModalMode !== null}
        okText="保存"
        cancelText="取消"
        confirmLoading={saving}
        onCancel={() => setSourceModalMode(null)}
        onOk={() => void saveSource()}
      >
        <Space direction="vertical" size={12} className="action-form">
          {sourceError ? <Alert type="error" content={sourceError} /> : null}
          <label>
            <Text>数据源名称</Text>
            <Input value={sourceDraft.name} placeholder="例如：行业资讯" onChange={(name) => setSourceDraft((current) => ({ ...current, name }))} />
          </label>
          <label>
            <Text>数据源类型</Text>
            <Input value={sourceDraft.kind === 'rss' ? 'RSS 订阅' : '历史数据源（仅维护）'} disabled />
          </label>
          <label>
            <Text>链接地址</Text>
            <Input
              value={sourceDraft.url}
              disabled={Boolean(editingSource?.builtIn || (editingSource && editingSource.kind !== 'rss'))}
              placeholder="https://example.com/feed"
              onChange={(url) => setSourceDraft((current) => ({ ...current, url }))}
            />
          </label>
          <label>
            <Text>图标地址</Text>
            <Input
              value={sourceDraft.iconUrl}
              disabled={Boolean(editingSource?.builtIn || (editingSource && editingSource.kind !== 'rss'))}
              placeholder="https://example.com/icon.png"
              onChange={(iconUrl) => setSourceDraft((current) => ({ ...current, iconUrl }))}
            />
          </label>
          <label>
            <Text>说明</Text>
            <TextArea rows={4} value={sourceDraft.description} placeholder="数据源用途或内容范围" onChange={(description) => setSourceDraft((current) => ({ ...current, description }))} />
          </label>
          <label>
            <Space>
              <Switch checked={sourceDraft.enabled} onChange={(enabled) => setSourceDraft((current) => ({ ...current, enabled }))} />
              <Text>启用采集</Text>
            </Space>
          </label>
        </Space>
      </Modal>
    </div>
  )
}

function sourceByID(sources: DataSourceCard[], id: string): DataSourceCard {
  return sources.find((source) => source.id === id) ?? sources[0]
}

function sourceIcon(kind: DatasetSourceKind) {
  if (kind === 'rss') return <IconStorage />
  if (kind === 'manual') return <IconCompass />
  return <IconLink />
}

function sourceColor(kind: DatasetSourceKind) {
  if (kind === 'rss') return 'orange'
  if (kind === 'manual') return 'green'
  return 'blue'
}

function sourceInitial(name: string) {
  return Array.from(name.trim())[0] || '源'
}

function itemTime(item: DatasetItemDTO) {
  const value = item.publishedAt ?? item.createdAt
  const parsed = new Date(value)
  if (Number.isNaN(parsed.getTime())) return ''
  return new Intl.DateTimeFormat('zh-CN', { dateStyle: 'medium' }).format(parsed)
}

function sourceSubtitle(source: DatasetSourceDTO) {
  if (!source.lastSyncedAt) return `${source.itemCount} 条`
  const parsed = new Date(source.lastSyncedAt)
  if (Number.isNaN(parsed.getTime())) return `${source.itemCount} 条`
  return `${source.itemCount} 条 · ${new Intl.DateTimeFormat('zh-CN', { dateStyle: 'short', timeStyle: 'short' }).format(parsed)}`
}