import { Alert, Empty, Modal, Segmented, Space, Tag, TreeSelect, Typography } from 'antd'
import { useEffect, useMemo, useState } from 'react'

import type {
  AdminConsignmentProfilesResponse,
  ConsignmentProfile,
  ConsignmentProfileConfig,
} from '@/types/consignment'
import { buildConsignmentCategoryGroups } from '@/utils/consignment-category-tree'

const { Text } = Typography

export type ConsignmentTemplateCopyMode = 'specs' | 'intake'
export type ConsignmentTemplateCopyVersion = 'published' | 'draft'

export type ConsignmentTemplateCopySelection = {
  profile: ConsignmentProfile
  config: ConsignmentProfileConfig
  version: ConsignmentTemplateCopyVersion
}

type Category = AdminConsignmentProfilesResponse['categories'][number]

type TemplateOption = {
  value: number
  label: string
  disabled: boolean
  profile: ConsignmentProfile
  config: ConsignmentProfileConfig | null
  fields: Array<{ label: string; detail: string }>
}

type TemplateTreeNode = {
  key: string
  value: number
  title: string
  selectable: boolean
  disabled?: boolean
  kind: 'group' | 'root' | 'child'
  option?: TemplateOption
  groupCount?: number
  children?: TemplateTreeNode[]
}

function resolveCategoryPath(
  profile: ConsignmentProfile,
  categoryNames: Map<number, string>,
): string {
  const ownName =
    profile.categoryName || categoryNames.get(profile.categoryId) || profile.name || '未命名分类'
  if (!profile.categoryParentId) return ownName
  const parentName =
    profile.categoryParentName || categoryNames.get(profile.categoryParentId) || '上级分类'
  return `${parentName} / ${ownName}`
}

function resolveTemplateConfig(
  profile: ConsignmentProfile,
  version: ConsignmentTemplateCopyVersion,
): ConsignmentProfileConfig | null {
  return version === 'published' ? (profile.publishedConfig ?? null) : profile.config
}

function resolveTemplateFields(
  config: ConsignmentProfileConfig,
  mode: ConsignmentTemplateCopyMode,
): Array<{ label: string; detail: string }> {
  if (mode === 'specs') {
    return config.specs.map((spec) => ({
      label: spec.label || spec.key,
      detail:
        spec.type === 'select' || spec.type === 'radio'
          ? `${spec.type} · ${spec.options.filter((option) => option.enabled !== false).length} 个选项`
          : spec.type,
    }))
  }
  return (config.intake?.fields ?? []).map((field) => ({
    label: field.label || field.key,
    detail: `${field.type}${field.required ? ' · 必填' : ''}`,
  }))
}

/** 按一级分类聚合排序：一级在前，其二级紧随其后，孤立二级排在最后。 */
function orderProfilesByCategory(profiles: ConsignmentProfile[]): ConsignmentProfile[] {
  const roots: ConsignmentProfile[] = []
  const childrenByParent = new Map<number, ConsignmentProfile[]>()
  for (const profile of profiles) {
    if (profile.categoryParentId) {
      const list = childrenByParent.get(profile.categoryParentId) || []
      list.push(profile)
      childrenByParent.set(profile.categoryParentId, list)
    } else {
      roots.push(profile)
    }
  }

  const ordered: ConsignmentProfile[] = []
  const included = new Set<number>()
  for (const root of roots) {
    ordered.push(root)
    included.add(root.profileId)
    for (const child of childrenByParent.get(root.categoryId) || []) {
      if (included.has(child.profileId)) continue
      ordered.push(child)
      included.add(child.profileId)
    }
  }
  // 只有二级配置、没有一级配置的历史数据：仍需可选，排到最后。
  for (const profile of profiles) {
    if (included.has(profile.profileId)) continue
    ordered.push(profile)
    included.add(profile.profileId)
  }
  return ordered
}

export default function ConsignmentTemplateCopyModal({
  open,
  mode,
  currentCategoryId,
  categories,
  profiles,
  onCancel,
  onApply,
}: {
  open: boolean
  mode: ConsignmentTemplateCopyMode
  currentCategoryId: number | null
  categories: Category[]
  profiles: ConsignmentProfile[]
  onCancel: () => void
  onApply: (selection: ConsignmentTemplateCopySelection) => void
}) {
  const [version, setVersion] = useState<ConsignmentTemplateCopyVersion>('published')
  const [selectedProfileId, setSelectedProfileId] = useState<number | null>(null)
  const [treeExpandedKeys, setTreeExpandedKeys] = useState<Array<string | number>>([])

  const categoryNames = useMemo(
    () => new Map(categories.map((category) => [category.categoryId, category.name])),
    [categories],
  )

  const selectableProfiles = useMemo(
    () =>
      orderProfilesByCategory(
        profiles.filter((profile) => profile.categoryId !== currentCategoryId),
      ),
    [profiles, currentCategoryId],
  )

  const hasPublished = selectableProfiles.some((profile) => Boolean(profile.publishedConfig))

  const options = useMemo<TemplateOption[]>(
    () =>
      selectableProfiles.map((profile) => {
        const config = resolveTemplateConfig(profile, version)
        const fields = config ? resolveTemplateFields(config, mode) : []
        const versionLabel =
          version === 'published'
            ? profile.currentVersionNo
              ? `v${profile.currentVersionNo}`
              : '未发布'
            : '草稿'
        const statusSuffix = profile.status === 'archived' ? ' · 已归档' : ''
        const ownName = profile.categoryName || profile.name || '未命名分类'
        return {
          value: profile.profileId,
          label: `${ownName}（${versionLabel}${statusSuffix}）`,
          disabled: fields.length === 0,
          profile,
          config,
          fields,
        }
      }),
    [selectableProfiles, version, mode],
  )

  const treeData = useMemo<TemplateTreeNode[]>(() => {
    const groups = buildConsignmentCategoryGroups({
      items: options,
      getCategoryId: (option) => option.profile.categoryId,
      getParentId: (option) => option.profile.categoryParentId,
      getParentName: (option) => option.profile.categoryParentName,
      getFallbackName: (option) => resolveCategoryPath(option.profile, categoryNames),
    })

    return groups.flatMap((group) => {
      const root = group.root
      const rootLabel = root?.label || group.groupName || '未命名分类'
      const childNodes: TemplateTreeNode[] = group.children.map((option) => ({
        key: `child-${option.value}`,
        value: option.value,
        title: option.label,
        selectable: true,
        disabled: option.disabled,
        kind: 'child',
        option,
      }))
      if (root && childNodes.length === 0) {
        return [
          {
            key: `root-${root.value}`,
            value: root.value,
            title: root.label,
            selectable: true,
            disabled: root.disabled,
            kind: 'root',
            option: root,
          },
        ]
      }
      if (!root) {
        if (childNodes.length === 0) return []
        const groupNode: TemplateTreeNode = {
          key: `group-${group.groupCategoryId}`,
          value: -group.groupCategoryId,
          title: rootLabel,
          selectable: false,
          kind: 'group',
          groupCount: childNodes.length,
          children: childNodes,
        }
        return [groupNode]
      }
      return [
        {
          key: `group-${group.groupCategoryId}`,
          value: root.value,
          title: root.label,
          selectable: !root.disabled,
          kind: 'group',
          option: root,
          groupCount: childNodes.length,
          children: childNodes,
        },
      ]
    })
  }, [options, categoryNames])
  const treeGroupKeys = useMemo(
    () => treeData.filter((node) => node.children?.length).map((node) => node.key),
    [treeData],
  )

  useEffect(() => {
    if (!open) return
    setVersion(hasPublished ? 'published' : 'draft')
    setSelectedProfileId(null)
  }, [open, hasPublished])

  useEffect(() => {
    if (!open) return
    setTreeExpandedKeys(treeGroupKeys)
  }, [open, version, mode, treeGroupKeys])

  useEffect(() => {
    if (!open) return
    if (
      selectedProfileId !== null &&
      options.some((option) => option.value === selectedProfileId && !option.disabled)
    ) {
      return
    }
    setSelectedProfileId(options.find((option) => !option.disabled)?.value ?? null)
  }, [open, options, selectedProfileId])

  const selectedOption = options.find((option) => option.value === selectedProfileId) || null
  const selectedFields = selectedOption?.fields || []

  return (
    <Modal
      open={open}
      width={680}
      title={mode === 'specs' ? '复制规格字段模板' : '复制联系方式模板'}
      okText="复制到当前配置"
      cancelText="取消"
      okButtonProps={{ disabled: !selectedOption || selectedFields.length === 0 }}
      onOk={() => {
        if (!selectedOption?.config) return
        onApply({
          profile: selectedOption.profile,
          config: selectedOption.config,
          version,
        })
      }}
      onCancel={onCancel}
    >
      <Space direction="vertical" size={12} style={{ width: '100%' }}>
        <Space size={12} wrap>
          <Text type="secondary">来源版本</Text>
          <Segmented
            value={version}
            options={[
              { label: '已发布版本', value: 'published', disabled: !hasPublished },
              { label: '当前草稿', value: 'draft' },
            ]}
            onChange={(value) => setVersion(value as ConsignmentTemplateCopyVersion)}
          />
        </Space>

        <TreeSelect<number, TemplateTreeNode>
          style={{ width: '100%' }}
          placeholder={
            options.some((option) => !option.disabled)
              ? '请选择要复制的寄卖配置'
              : '没有可复制的寄卖配置'
          }
          value={selectedProfileId ?? undefined}
          treeData={treeData}
          treeDefaultExpandAll
          treeExpandedKeys={treeExpandedKeys}
          onTreeExpand={(keys) => setTreeExpandedKeys(keys as Array<string | number>)}
          showSearch={{
            treeNodeFilterProp: 'title',
            onSearch: () => setTreeExpandedKeys(treeGroupKeys),
          }}
          onOpenChange={(open) => {
            if (!open) setTreeExpandedKeys(treeGroupKeys)
          }}
          popupMatchSelectWidth={false}
          listHeight={320}
          treeTitleRender={(node) => {
            const item = node as TemplateTreeNode
            if (item.kind === 'group') {
              return (
                <span style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
                  <span style={{ flex: 1 }}>{item.title}</span>
                  {item.option ? <Tag color="blue">一级</Tag> : null}
                </span>
              )
            }
            if (!item.option) return item.title
            return (
              <span style={{ display: 'flex', alignItems: 'center', gap: 6 }}>
                <span style={{ flex: 1 }}>{item.option.label}</span>
                {item.kind === 'root' ? <Tag color="blue">一级</Tag> : <Tag>二级</Tag>}
                {item.option.fields.length === 0 ? <Tag>无字段</Tag> : null}
              </span>
            )
          }}
          onChange={(value) => {
            if (typeof value === 'number' && value > 0) setSelectedProfileId(value)
          }}
        />

        {version === 'draft' && selectedOption?.profile.status === 'published' ? (
          <Alert
            type="info"
            showIcon
            message="当前复制的是后台保存的草稿，不是线上已发布版本；如需线上配置请切换为「已发布版本」。"
          />
        ) : null}

        {mode === 'specs' && selectedOption?.config?.specSource === 'template' ? (
          <Alert
            type="warning"
            showIcon
            message="来源是模板驱动规格：复制后 ruleKey 仍指向来源分类的接单模板，价格会按来源模板计算。"
            description="如果希望按当前分类的接单模板取价，请改用「从接单模板生成」。"
          />
        ) : null}

        {selectedOption && selectedFields.length > 0 ? (
          <div>
            <Text strong>
              将复制 {selectedFields.length} 个{mode === 'specs' ? '规格字段' : '联系方式字段'}
            </Text>
            <div
              style={{
                marginTop: 8,
                display: 'flex',
                flexWrap: 'wrap',
                gap: 6,
                maxHeight: 240,
                overflowY: 'auto',
              }}
            >
              {selectedFields.map((field) => (
                <Tag key={`${field.label}-${field.detail}`}>
                  {field.label} · {field.detail}
                </Tag>
              ))}
            </div>
            {selectedOption.config ? (
              <Text type="secondary" style={{ display: 'block', marginTop: 8 }}>
                复制只替换当前区块，不影响价格、保证金、服务费、匹配和超时设置；应用后请点「保存草稿」。
              </Text>
            ) : null}
          </div>
        ) : (
          <Empty
            image={Empty.PRESENTED_IMAGE_SIMPLE}
            description={
              options.length > 0
                ? '该版本没有可复制的字段，请换一个配置或切换版本'
                : version === 'published'
                  ? '没有可用的已发布配置，请切换到「当前草稿」'
                  : '没有可复制的字段'
            }
          />
        )}
      </Space>
    </Modal>
  )
}