import { createContext, useContext, useRef } from 'react'
import { create } from 'zustand'
import { useShallow } from 'zustand/shallow'
import type { PersistStoreProviderProps } from '../types.js'
import type { HeaderState, HeaderStore } from './types.js'

const HeaderStoreContext = createContext<HeaderStore | null>(null)

export function HeaderStoreProvider({ children }: PersistStoreProviderProps) {
  const storeRef = useRef<HeaderStore>(null)
  if (!storeRef.current) {
    storeRef.current = createHeaderStore()
  }
  return (
    <HeaderStoreContext.Provider value={storeRef.current}>
      {children}
    </HeaderStoreContext.Provider>
  )
}

function useHeaderStoreContext() {
  const useStore = useContext(HeaderStoreContext)
  if (!useStore) {
    throw new Error(
      `You forgot to wrap your component in <${HeaderStoreProvider.name}>.`
    )
  }
  return useStore
}

export function useHeaderStore<T>(selector: (state: HeaderState) => T): T {
  const useStore = useHeaderStoreContext()
  return useStore(useShallow(selector))
}

// We use fixed position on the header when Widget is in Full Height layout.
// We do this to get it to work like the sticky header does in the other layout modes.
// As the header is position fixed its not in the document flow anymore.
// To prevent the remaining page content from appearing behind the header we need to
// pass the headers height so that the position of the page content can be adjusted
export function useHeaderHeight() {
  const headerHeight = useHeaderStore((state) => state.headerHeight)

  return {
    headerHeight,
  }
}

export function useSetHeaderHeight() {
  const setHeaderHeight = useHeaderStore((state) => state.setHeaderHeight)

  return {
    setHeaderHeight,
  }
}

const createHeaderStore = () =>
  create<HeaderState>((set, get) => ({
    headerHeight: 108, // a basic default height
    setAction: (element) => {
      set(() => ({
        element,
      }))
      return get().removeAction
    },
    setTitle: (title) => {
      set(() => ({
        title,
      }))
      return get().removeTitle
    },
    removeAction: () => {
      set(() => ({
        element: null,
      }))
    },
    removeTitle: () => {
      set(() => ({
        title: undefined,
      }))
    },
    setHeaderHeight: (headerHeight) => {
      set(() => ({
        headerHeight,
      }))
    },
  }))