// Server-filtered navigation (D-10). The server removes items the admin may
// not open; the rail also omits a plugin whose side menu ends up empty.
import { computed, readonly, ref } from 'vue'
import { api } from '../api/client'
import type { NavigationEntry } from '../api/types'
import { controllerPath, pluginKey } from '../app/controllerRoutes'

const entries = ref<NavigationEntry[]>([])

export const navigation = readonly(entries)

export async function loadNavigation(): Promise<NavigationEntry[]> {
  const { data, response } = await api.GET('/navigation')
  entries.value = response.ok && data ? data.data : []
  return entries.value
}

export function setNavigation(next: NavigationEntry[]): void {
  entries.value = next
}

/** Rail entries: plugins with at least one permitted side-menu item, by order. */
export const railEntries = computed<NavigationEntry[]>(() =>
  entries.value
    .filter((entry) => entry.sideMenu.length > 0)
    .map((entry, index) => ({ entry, index }))
    .sort((a, b) => a.entry.order - b.entry.order || a.index - b.index)
    .map(({ entry }) => entry),
)

/** Path of the plugin's first permitted side-menu controller. */
export function firstControllerPath(entry: NavigationEntry): string | null {
  for (const item of entry.sideMenu) {
    const path = controllerPath(item.controller)
    if (path) {
      return path
    }
  }
  return controllerPath(entry.controller)
}

/** The rail entry owning a route's vendor and plugin segments. */
export function activeEntry(vendor: string, plugin: string): NavigationEntry | null {
  const key = `${vendor}.${plugin}`
  return (
    railEntries.value.find(
      (entry) => pluginKey(entry.controller) === key || entry.sideMenu.some((item) => pluginKey(item.controller) === key),
    ) ?? null
  )
}

/** Where "/" lands: the first plugin's first controller. */
export function homePath(): string | null {
  for (const entry of railEntries.value) {
    const path = firstControllerPath(entry)
    if (path) {
      return path
    }
  }
  return null
}

export function useNavigation() {
  return { navigation, railEntries, loadNavigation, firstControllerPath, activeEntry, homePath }
}