import { useQuery } from "@tanstack/react-query"
import { useNavigate } from "@tanstack/react-router"
import {
  Bell,
  Box,
  KeyRound,
  LayoutDashboard,
  LayoutGrid,
  type LucideIcon,
  MonitorSmartphone,
  Package,
  Server,
  Workflow,
} from "lucide-react"
import { useState } from "react"

import { type SearchEntry, SearchService } from "@/client"
import {
  CommandDialog,
  CommandEmpty,
  CommandGroup,
  CommandInput,
  CommandItem,
  CommandList,
} from "@/components/ui/command"

export const searchQueryOptions = () => ({
  queryKey: ["search"] as const,
  queryFn: () => SearchService.readSearchIndex(),
  staleTime: 30_000,
})

/** The categories, in the order they are offered, with what to draw each as. */
//: The most entries one group shows. cmdk scores what is mounted, so this is
//: a cap on what is offered rather than on what is searched — and twenty of a
//: kind is already more than anybody reads before typing another letter.
const GROUP_CAP = 20

const GROUPS: {
  category: SearchEntry["category"]
  label: string
  icon: LucideIcon
}[] = [
  { category: "flow", label: "Flows", icon: Workflow },
  { category: "node", label: "Nodes", icon: Box },
  { category: "dashboard", label: "Dashboards", icon: LayoutDashboard },
  { category: "widget", label: "Widgets", icon: LayoutGrid },
  { category: "panel", label: "Panels", icon: MonitorSmartphone },
  { category: "secret", label: "Secrets", icon: KeyRound },
  { category: "module", label: "Modules", icon: Package },
  { category: "worker", label: "Workers", icon: Server },
  { category: "alert", label: "Alerts", icon: Bell },
]

/** The second line: where the thing lives, and what kind it is. */
function hint(entry: SearchEntry): string {
  return [entry.parent, entry.kind].filter(Boolean).join(" · ")
}

/**
 * Everything in this installation, by name, from anywhere.
 *
 * The whole index arrives in one fetch and `cmdk` does the matching, so results
 * narrow as they are typed without a round trip per keystroke.
 *
 * cmdk does the matching over what is mounted, so the entries are bucketed by
 * category once per fetch rather than filtered nine times per keystroke, and
 * each group is capped — a list nobody can scroll to the end of is not a
 * better answer than its first twenty.
 */
export function GlobalSearch({
  open,
  onOpenChange,
}: {
  open: boolean
  onOpenChange: (open: boolean) => void
}) {
  const navigate = useNavigate()
  const [query, setQuery] = useState("")
  const { data } = useQuery({ ...searchQueryOptions(), enabled: open })

  // Picking an item navigates, which can interrupt the dialog's exit animation
  // and leave its overlay swallowing clicks — the same reason the flow canvas
  // palette unmounts outright rather than fading out.
  if (!open) return null

  const entries = data ?? []
  const typing = query.trim().length > 0
  // One pass over the index rather than one per group — nine passes over
  // every entry on each keystroke. Not memoised: the component returns early
  // while closed, so a hook cannot go here, and one pass is already the win.
  const byCategory = new Map<string, SearchEntry[]>()
  for (const entry of entries) {
    const bucket = byCategory.get(entry.category)
    if (bucket) bucket.push(entry)
    else byCategory.set(entry.category, [entry])
  }

  const go = (entry: SearchEntry) => {
    onOpenChange(false)
    setQuery("")
    switch (entry.category) {
      case "flow":
        return navigate({
          to: "/flows/$flowName",
          params: { flowName: entry.name },
        })
      case "node":
        return navigate({
          to: "/flows/$flowName",
          params: { flowName: entry.parent ?? "" },
          search: { node: entry.name },
        })
      case "dashboard":
        return navigate({
          to: "/dashboards/$name",
          params: { name: entry.name },
        })
      case "widget":
        return navigate({
          to: "/dashboards/$name",
          params: { name: entry.parent ?? "" },
        })
      // Panels are managed in a dialog on the dashboards screen, which opens
      // itself when the address says so.
      case "panel":
        return navigate({ to: "/dashboards", search: { panels: true } })
      case "secret":
        return navigate({ to: "/secrets" })
      case "module":
        return navigate({ to: "/modules" })
      case "worker":
        return navigate({ to: "/workers" })
      case "alert":
        return navigate({ to: "/alerts" })
    }
  }

  return (
    // Frosted chrome, a little above centre. `top-[40%]` against the dialog's
    // own `-translate-y-1/2` puts the panel's middle at two fifths of the
    // viewport; the inner Command paints its own surface, which has to give way
    // to this one.
    <CommandDialog
      open={open}
      onOpenChange={onOpenChange}
      title="Search"
      description="Find a flow, node, dashboard or widget"
      showCloseButton={false}
      className="top-[40%] bg-popover/80 shadow-e3 backdrop-blur-md sm:max-w-xl [&_[data-slot=command]]:bg-transparent"
    >
      <CommandInput
        value={query}
        onValueChange={setQuery}
        placeholder="Search flows, nodes, dashboards, widgets…"
        data-testid="global-search-input"
      />
      <CommandList className="max-h-[min(24rem,60svh)]">
        {typing ? (
          <>
            <CommandEmpty>Nothing matches that.</CommandEmpty>
            {GROUPS.map(({ category, label, icon: Icon }) => {
              const found = (byCategory.get(category) ?? []).slice(0, GROUP_CAP)
              if (found.length === 0) return null
              return (
                <CommandGroup key={category} heading={label}>
                  {found.map((entry) => (
                    <CommandItem
                      key={`${category}:${entry.parent ?? ""}:${entry.name}`}
                      value={`${entry.name} ${entry.title ?? ""} ${entry.parent ?? ""} ${entry.kind ?? ""}`}
                      onSelect={() => go(entry)}
                      className="min-h-11 md:min-h-8"
                    >
                      <Icon />
                      <span className="flex min-w-0 flex-col">
                        <span className="truncate">
                          {entry.title || entry.name}
                        </span>
                        {hint(entry) ? (
                          <span className="truncate text-xs text-muted-foreground">
                            {hint(entry)}
                          </span>
                        ) : null}
                      </span>
                    </CommandItem>
                  ))}
                </CommandGroup>
              )
            })}
          </>
        ) : (
          <p className="py-6 text-center text-sm text-muted-foreground">
            Start typing to search this installation.
          </p>
        )}
      </CommandList>
    </CommandDialog>
  )
}