import Vue from 'vue'
import router from '@/router'

import api from '@/api'
import {
  parseNodesQueryParams,
  getUniqueNodesIds,
  getRelatedNodesIds,
  getRandomIds,
  parseTree,
  buildTree
} from '@/store/utils.js'


export default {
  state: {
    trees: {},
    randomNodes: undefined,
    nodebook: [],

    // LibraryOptions options
    tagsOptions: [],
    // LibraryOptions state
    mode: undefined,
    nodeDepartId: undefined,
    search: '',
    tags: [],
    strangeness: undefined
  },

  mutations: {
    // ╷  ╶┬╴┌─╮┌─╮╭─┐┌─╮╷ ╷
    // │   │ │╶┤├┬╯├─┤├┬╯╰─┤
    // ╰─╴╶┴╴└─╯╵ ╰╵ ╵╵ ╰╶─╯

    'SET_NODEBOOK' (state, nodes) {
      state.nodebook = nodes
    },

    'ADD_NODEBOOK_NODE' (state, [stack, parentId, childId]) {
      if (stack === undefined) {
        stack = childId === undefined ? [parentId] : [parentId, childId]
        state.nodebook.push(stack)
        return
      }
      if (stack !== undefined && parentId !== undefined) {
        state.nodebook.push(state.nodebook.splice(state.nodebook.indexOf(stack), 1)[0])
      }
      if (childId) {
        if (stack.includes(childId)) {
          stack.push(stack.splice(stack.indexOf(childId), 1)[0])
        } else {
          stack.push(childId)
        }
      }
    },

    'REMOVE_NODEBOOK_NODE' (state, [stack, nodeId]) {
      if (stack[0] === nodeId) {
        state.nodebook.splice(state.nodebook.indexOf(stack), 1)
      } else {
        stack.splice(stack.indexOf(nodeId), 1)
      }
    },

    'ADD_NODE_TREE' (state, [id, tree]) {
      Vue.set(state.trees, id, tree)
    },

    // ╭─╮┌─╮╶┬╴╶┬╴╭─╮╭╮╷╭─╴
    // │ │├─╯ │  │ │ ││││╰─╮
    // ╰─╯╵   ╵ ╶┴╴╰─╯╵╰╯╶─╯

    'SET_TAGS_OPTIONS' (state, nodes) {
      const tags = nodes.reduce((tags, node) => tags.concat(node.tags || []), [])
      state.tagsOptions = Array.from(new Set(tags.map(tag => tag.name)))
    },

    'UPDATE_TAGS' (state, tags) {
      state.tags = tags
    },

    'UPDATE_STRANGENESS' (state, strangenessLvl) {
      state.strangeness = strangenessLvl
    },

    'SET_MODE' (state, mode) {
      state.mode = mode
    },

    'SET_NODE_DEPART_ID' (state, id) {
      state.nodeDepartId = id
    },

    'SET_RANDOM_NODES' (state, ids) {
      state.randomNodes = ids
    },

    'SET_SEARCH' (state, str) {
      state.search = str
    }
  },

  actions: {
    // ╷  ╶┬╴┌─╮┌─╮╭─┐┌─╮╷ ╷
    // │   │ │╶┤├┬╯├─┤├┬╯╰─┤
    // ╰─╴╶┴╴└─╯╵ ╰╵ ╵╵ ╰╶─╯

    async 'INIT_LIBRARY' ({ state, commit, dispatch, rootState }, { dataLevel = 'initial' } = {}) {
      await dispatch('GET_ALL_NODES_IDS', { variant: 'depart', dataLevel })
      if (state.nodebook && state.nodebook.length) {
        commit('UPDATE_OPTIONS_VISIBILITY', false)
      }
      return rootState.ids.depart
    },

    async 'INIT_LIBRARY_TREE' ({ state, commit, dispatch, rootState }) {
      const ids = await dispatch('INIT_LIBRARY')
      // set Katalin Molnár "Quant à je" (id: 8) as default selected node
      return dispatch('SET_NODE_DEPART_ID', 8)
    },

    async 'INIT_LIBRARY_MAP' ({ state, commit, dispatch }) {
      await dispatch('INIT_LIBRARY')
      return dispatch('ROLL_RANDOM_NODES')
    },

    async 'INIT_LIBRARY_LIST' ({ state, commit, dispatch }) {
      const departIds = await dispatch('INIT_LIBRARY', { dataLevel: 'partial' })
      const nodes = await dispatch('GET_NODES', { ids: departIds, dataLevel: 'partial' })
      commit('SET_TAGS_OPTIONS', nodes)
      return nodes
    },

    async 'UPDATE_NODEBOOK' ({ state, commit, dispatch }, query) {
      const { mode = 'tree', nodebook } = parseNodesQueryParams(query)
      commit('SET_MODE', mode)
      const ids = [].concat(...nodebook)
      await dispatch('GET_NODES', { ids, dataLevel: 'full' })
      commit('SET_NODEBOOK', nodebook)
      commit('ADD_HISTORY_ENTRIES', ids)
    },

    // ╭╮╷╭─╮┌─╮┌─╴╭─╴
    // ││││ ││ │├─╴╰─╮
    // ╵╰╯╰─╯└─╯╰─╴╶─╯

    'UPDATE_QUERY_NODES' ({ state }) {
      const query = {
        mode: state.mode,
        nodes: [...state.nodebook.map(ids => ids.join(','))]
      }
      if (router.currentRoute.name !== 'library') {
        router.push({ name: 'library', query })
      } else {
        router.push({ query })
      }
    },

    async 'OPEN_NODE' ({ state, commit, dispatch }, { parentId, childId }) {
      if (state.nodebook === undefined || !state.nodebook.length) {
        commit('UPDATE_OPTIONS_VISIBILITY', false)
      }
      const stack = state.nodebook.find(stack => stack[0] === parentId)
      commit('ADD_NODEBOOK_NODE', [stack, parentId, childId])
      dispatch('UPDATE_QUERY_NODES')
      commit('ADD_HISTORY_ENTRIES', [childId || parentId])
    },

    'CLOSE_NODE' ({ state, commit, dispatch }, { parentId, childId }) {
      const stack = state.nodebook.find(stack => stack.includes(parentId) && (childId ? stack.includes(childId) : true))
      commit('REMOVE_NODEBOOK_NODE', [stack, childId || parentId])
      if (!state.nodebook.length) {
        commit('UPDATE_OPTIONS_VISIBILITY', true)
      }
      dispatch('UPDATE_QUERY_NODES')
    },

    // ╭─╮┌─╮╶┬╴╶┬╴╭─╮╭╮╷╭─╴
    // │ │├─╯ │  │ │ ││││╰─╮
    // ╰─╯╵   ╵ ╶┴╴╰─╯╵╰╯╶─╯

    async 'SET_NODE_DEPART_ID' ({ state, rootState, commit, dispatch, getters }, id) {
      if (state.nodeDepartId === id) return

      commit('SET_NODE_DEPART_ID', id)

      if (!(id in state.trees)) {
        const treeData = parseTree(await api.queryRecursiveNodes([id]))
        const nodes = await dispatch('GET_NODES', { ids: getUniqueNodesIds(treeData), dataLevel: 'initial' })
        commit('ADD_NODE_TREE', [id, buildTree(treeData, nodes)])
      }

      return getters.nodeTree
    },

    async 'ROLL_RANDOM_NODES' ({ state, rootState, commit, dispatch }) {
      commit('SET_RANDOM_NODES', undefined)
      const ids = getRandomIds(rootState.ids.depart)
      const departNodes = await dispatch('GET_NODES', { ids, dataLevel: 'partial' })
      const relatedIds = getRelatedNodesIds(departNodes, ids)
      const relatedNodes = await dispatch('GET_NODES', { ids: relatedIds, dataLevel: 'partial' })
      const nodes = [...departNodes, ...relatedNodes]
      commit('SET_RANDOM_NODES', [...ids, ...relatedIds])
      commit('SET_TAGS_OPTIONS', nodes)
    },

    'UPDATE_QUERY_MODE' (store, mode) {
      if (router.currentRoute.query.mode === mode) return
      router.push({ query: { mode } })
    }
  },

  getters: {
    // LibraryOptions state
    mode: state => state.mode,
    nodeDepartId: state => state.nodeDepartId,
    search: state => state.search,
    tags: state => state.tags,
    strangeness: state => state.strangeness,

    // LibraryOptions options
    tagsOptions: state => state.tagsOptions,

    nodesDeparts: (state, getters, rootState) => {
      const departIds = rootState.ids.depart
      if (departIds === undefined) return
      const nodes = departIds.map(id => rootState.nodes[id])
      if (nodes.some(node => node === undefined)) return
      return nodes
    },

    nodesDepartsOptions: (state, getters, rootState) => {
      const nodes = getters.nodesDeparts
      if (nodes === undefined) return
      return nodes.sort((a, b) => {
        const prev = a.authors[0].last_name.toLowerCase()
        const next = b.authors[0].last_name.toLowerCase()
        if (prev === next) return 0
        return prev < next ? -1 : 1
      })
    },

    // Library
    nodebook: (state, getters, rootState) => {
      return state.nodebook.map(([parentId, ...childrenIds]) => {
        return {
          parent: rootState.nodes[parentId],
          children: childrenIds.map(id => rootState.nodes[id])
        }
      })
    },

    // LibraryList
    orderedTextsDepart: (state, getters, rootState) => {
      const departIds = rootState.ids.depart
      if (departIds === undefined || rootState.nodes[departIds[0]] === undefined) return
      const nodesDict = {}
      for (const node of rootState.ids.depart.map(id => rootState.nodes[id])) {
        if (!node.authors) {
          if (!('~' in nodesDict)) nodesDict['~'] = []
          nodesDict['~'].push(node)
        } else {
          node.authors.forEach((author, i) => {
            const firstChar = author.last_name[0].toUpperCase()
            if (!(firstChar in nodesDict)) nodesDict[firstChar] = []
            nodesDict[firstChar].push({ last_name: author.last_name, node })
          })
        }
      }
      return Object.entries(nodesDict).sort((a, b) => a[0] < b[0] ? -1 : 1).map(group => {
        if (group[0] === '~') return group
        return [group[0], group[1].sort((a, b) => {
          const prev = a.last_name.toLowerCase()
          const next = b.last_name.toLowerCase()
          return prev.localeCompare(next)
        }).map(node => node.node)]
      })
    },

    // LibraryMap
    randomNodes: (state, getters, rootState) => {
      if (state.randomNodes === undefined) return
      return state.randomNodes.map(id => rootState.nodes[id])
    },

    // LibraryTree
    nodeTree: state => {
      return state.trees[state.nodeDepartId] || { nodes: [], links: [] }
    },

    // Commons
    activeNodes: state => {
      if (!state.nodebook) return []
      return state.nodebook.reduce((acc, ids) => [...acc, ...ids], [])
    }
  }
}