"use client"

// Order of Merit (ADR-043 [OOM]): sesong-sammenlagt rangering av spillere
// på tvers av flere individuelle turneringer (ADR-037) i samme
// organisasjon. Håndkodet (ikke V0 -- ingen V0-credits tilgjengelig denne
// runden), men bevisst bygget til å matche samme visuelle presisjon som
// V0-eksportene ellers i appen (samme design-tokens, samme kort-/
// header-mønster som org-members.tsx).

import type React from "react"
import { useEffect, useState } from "react"
import Link from "next/link"
import { useRouter } from "next/navigation"
import { ArrowLeft, ChevronRight, Plus, Trophy, Users } from "lucide-react"
import { Button } from "@/components/ui/button"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"
import { cn } from "@/lib/utils"

type OomKind = "player" | "team"
type OomResultType = "points" | "stableford" | "gross" | "net" | "money"
type OomAggregationMode = "sum" | "average" | "eclectic"

// Eclectic-aggregering (ADR-075) krever kind='player' og en resultattype
// med per-hull-granularitet (stableford/brutto/netto) -- håndhevet
// server-side (order_of_merit.py), speilet her for å skjule valget når
// det uansett ville blitt avvist.
function eclecticAllowed(kind: OomKind, resultType: OomResultType): boolean {
  return kind === "player" && (resultType === "stableford" || resultType === "gross" || resultType === "net")
}

type ApiOrderOfMerit = {
  id: string
  name: string
  kind: OomKind
  result_type: OomResultType
  aggregation_mode: OomAggregationMode
  count_best_n: number | null
  min_results_required: number | null
  birth_year_from: number | null
  birth_year_to: number | null
  public_visible: boolean
}

const KIND_LABELS: Record<OomKind, string> = { player: "Spiller", team: "Lag" }
const RESULT_TYPE_LABELS: Record<OomResultType, string> = {
  points: "Poeng etter plassering",
  stableford: "Stableford-sum",
  gross: "Bruttoscore-sum",
  net: "Nettoscore-sum",
  money: "Pengeliste",
}
const AGGREGATION_LABELS: Record<OomAggregationMode, string> = {
  sum: "Sum",
  average: "Snitt",
  eclectic: "Eclectic (drømmerunde)",
}

export function OrderOfMeritList({ organizationId, orgName }: { organizationId: string; orgName: string }) {
  const router = useRouter()
  const [items, setItems] = useState<ApiOrderOfMerit[] | null>(null)
  const [creating, setCreating] = useState(false)
  const [error, setError] = useState<string | null>(null)

  async function load() {
    const res = await fetch(`/orgs/${organizationId}/order-of-merits`, { credentials: "include" })
    if (res.ok) setItems(await res.json())
  }

  useEffect(() => {
    void load()
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [organizationId])

  async function create(input: { name: string; kind: OomKind; result_type: OomResultType; aggregation_mode: OomAggregationMode }) {
    setError(null)
    try {
      const res = await fetch(`/orgs/${organizationId}/order-of-merits`, {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        credentials: "include",
        body: JSON.stringify(input),
      })
      if (!res.ok) throw new Error(`create: ${res.status}`)
      const created: ApiOrderOfMerit = await res.json()
      setCreating(false)
      router.push(`/organizations/${organizationId}/order-of-merit/${created.id}?name=${encodeURIComponent(orgName)}`)
    } catch {
      setError("Klarte ikke å opprette Order of Merit. Prøv igjen.")
    }
  }

  return (
    <div className="flex min-h-[100dvh] flex-col bg-background">
      <header className="sticky top-0 z-10 border-b border-border bg-background/80 backdrop-blur">
        <div className="mx-auto flex w-full max-w-2xl items-center gap-3 px-5 py-4">
          <Link
            href={`/organizations/${organizationId}/members?name=${encodeURIComponent(orgName)}`}
            aria-label="Tilbake til organisasjonen"
            className="flex size-10 shrink-0 items-center justify-center rounded-xl border border-border bg-card text-muted-foreground transition-colors hover:bg-accent/50 hover:text-foreground"
          >
            <ArrowLeft aria-hidden="true" className="size-5" />
          </Link>
          <div className="flex min-w-0 flex-col">
            <span className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">
              Order of Merit
            </span>
            <h1 className="truncate text-xl font-extrabold tracking-tight text-foreground">{orgName}</h1>
          </div>
        </div>
      </header>

      <main className="mx-auto w-full max-w-2xl flex-1 px-5 py-6 sm:py-8">
        {error && (
          <p role="alert" className="mb-4 text-sm font-medium text-destructive">
            {error}
          </p>
        )}

        <div className="mb-5 flex items-center justify-between gap-3">
          <p className="text-sm leading-relaxed text-muted-foreground text-pretty">
            Sesong-sammenlagt rangering av spillere på tvers av flere turneringer.
          </p>
          {!creating && (
            <Button
              type="button"
              onClick={() => setCreating(true)}
              className="h-11 shrink-0 rounded-2xl font-bold"
            >
              <Plus aria-hidden="true" className="size-4" />
              Ny Order of Merit
            </Button>
          )}
        </div>

        {creating && (
          <div className="mb-6">
            <CreateForm onCreate={create} onCancel={() => setCreating(false)} />
          </div>
        )}

        {items === null ? (
          <div className="flex justify-center py-16">
            <div
              aria-hidden="true"
              className="size-10 animate-spin rounded-full border-4 border-primary/20 border-t-primary"
            />
          </div>
        ) : items.length === 0 && !creating ? (
          <div className="flex flex-col items-center gap-3 rounded-3xl border border-dashed border-border bg-card/50 px-6 py-12 text-center">
            <div className="flex size-14 items-center justify-center rounded-2xl bg-muted">
              <Trophy aria-hidden="true" className="size-7 text-muted-foreground" />
            </div>
            <h2 className="text-base font-bold text-foreground">Ingen Order of Merit-er ennå</h2>
            <p className="max-w-sm text-sm leading-relaxed text-muted-foreground text-pretty">
              Sett opp en sesong-sammenlagt rangering på tvers av flere turneringer.
            </p>
            <Button type="button" onClick={() => setCreating(true)} className="mt-2 h-11 rounded-2xl font-bold">
              <Plus aria-hidden="true" className="size-4" />
              Ny Order of Merit
            </Button>
          </div>
        ) : (
          <ul className="flex flex-col gap-3">
            {items.map((oom) => (
              <li key={oom.id}>
                <Link
                  href={`/organizations/${organizationId}/order-of-merit/${oom.id}?name=${encodeURIComponent(orgName)}`}
                  className="flex items-center gap-4 rounded-2xl border border-border bg-card p-5 shadow-md shadow-black/8 transition-colors hover:border-primary/50 hover:bg-accent/40 focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-offset-2 focus-visible:ring-offset-background"
                >
                  <div className="flex size-12 shrink-0 items-center justify-center rounded-xl bg-muted">
                    {oom.kind === "team" ? (
                      <Users aria-hidden="true" className="size-6 text-muted-foreground" />
                    ) : (
                      <Trophy aria-hidden="true" className="size-6 text-muted-foreground" />
                    )}
                  </div>
                  <div className="flex min-w-0 flex-1 flex-col gap-1.5">
                    <span className="truncate text-base font-bold text-foreground">{oom.name}</span>
                    <div className="flex flex-wrap gap-1.5">
                      <Badge>{KIND_LABELS[oom.kind]}</Badge>
                      <Badge>{RESULT_TYPE_LABELS[oom.result_type]}</Badge>
                      <Badge>{AGGREGATION_LABELS[oom.aggregation_mode]}</Badge>
                    </div>
                  </div>
                  <ChevronRight aria-hidden="true" className="size-5 shrink-0 text-muted-foreground" />
                </Link>
              </li>
            ))}
          </ul>
        )}
      </main>
    </div>
  )
}

function Badge({ children }: { children: React.ReactNode }) {
  return (
    <span className="inline-flex items-center rounded-full bg-secondary px-2.5 py-1 text-xs font-semibold text-secondary-foreground">
      {children}
    </span>
  )
}

function SegmentButton({
  selected,
  onClick,
  children,
}: {
  selected: boolean
  onClick: () => void
  children: React.ReactNode
}) {
  return (
    <button
      type="button"
      onClick={onClick}
      aria-pressed={selected}
      className={cn(
        "flex min-h-11 items-center justify-center rounded-xl border px-3 py-2.5 text-sm font-semibold transition-colors",
        selected
          ? "border-primary bg-primary/10 text-foreground"
          : "border-border bg-card text-muted-foreground hover:bg-accent/50 hover:text-foreground",
      )}
    >
      {children}
    </button>
  )
}

function CreateForm({
  onCreate,
  onCancel,
}: {
  onCreate: (input: { name: string; kind: OomKind; result_type: OomResultType; aggregation_mode: OomAggregationMode }) => void
  onCancel: () => void
}) {
  const [name, setName] = useState("")
  const [kind, setKind] = useState<OomKind>("player")
  const [resultType, setResultType] = useState<OomResultType>("stableford")
  const [aggregationMode, setAggregationMode] = useState<OomAggregationMode>("sum")
  const [submitting, setSubmitting] = useState(false)

  const showEclectic = eclecticAllowed(kind, resultType)

  function selectKind(k: OomKind) {
    setKind(k)
    if (aggregationMode === "eclectic" && !eclecticAllowed(k, resultType)) setAggregationMode("sum")
  }
  function selectResultType(rt: OomResultType) {
    setResultType(rt)
    if (aggregationMode === "eclectic" && !eclecticAllowed(kind, rt)) setAggregationMode("sum")
  }

  async function handleSubmit(e: React.FormEvent) {
    e.preventDefault()
    if (!name.trim() || submitting) return
    setSubmitting(true)
    await onCreate({ name: name.trim(), kind, result_type: resultType, aggregation_mode: aggregationMode })
    setSubmitting(false)
  }

  return (
    <form
      onSubmit={handleSubmit}
      className="flex flex-col gap-5 rounded-3xl border border-border bg-card p-5 shadow-md shadow-black/8 sm:p-6"
    >
      <h2 className="text-base font-bold text-foreground">Ny Order of Merit</h2>

      <div className="flex flex-col gap-1.5">
        <Label htmlFor="oom-name" className="text-sm font-semibold">
          Navn
        </Label>
        <Input
          id="oom-name"
          autoFocus
          value={name}
          onChange={(e) => setName(e.target.value)}
          placeholder="F.eks. Klubbmesterskap-serien 2026"
          className="h-11 rounded-xl"
        />
      </div>

      <div className="flex flex-col gap-2">
        <span className="text-sm font-semibold text-foreground">Type</span>
        <div className="grid grid-cols-2 gap-2">
          <SegmentButton selected={kind === "player"} onClick={() => selectKind("player")}>
            Spiller
          </SegmentButton>
          <SegmentButton selected={kind === "team"} onClick={() => selectKind("team")}>
            Lag
          </SegmentButton>
        </div>
      </div>

      <div className="flex flex-col gap-2">
        <span className="text-sm font-semibold text-foreground">Resultattype</span>
        <div className="grid grid-cols-2 gap-2 sm:grid-cols-3">
          {(Object.keys(RESULT_TYPE_LABELS) as OomResultType[]).map((rt) => (
            <SegmentButton key={rt} selected={resultType === rt} onClick={() => selectResultType(rt)}>
              {RESULT_TYPE_LABELS[rt]}
            </SegmentButton>
          ))}
        </div>
      </div>

      <div className="flex flex-col gap-2">
        <span className="text-sm font-semibold text-foreground">Aggregering</span>
        <div className={`grid grid-cols-2 gap-2 ${showEclectic ? "sm:grid-cols-3" : ""}`}>
          <SegmentButton selected={aggregationMode === "sum"} onClick={() => setAggregationMode("sum")}>
            Sum
          </SegmentButton>
          <SegmentButton selected={aggregationMode === "average"} onClick={() => setAggregationMode("average")}>
            Snitt
          </SegmentButton>
          {showEclectic && (
            <SegmentButton selected={aggregationMode === "eclectic"} onClick={() => setAggregationMode("eclectic")}>
              Eclectic
            </SegmentButton>
          )}
        </div>
      </div>

      <div className="flex gap-2">
        <Button type="submit" disabled={!name.trim() || submitting} className="h-11 flex-1 rounded-xl font-bold">
          {submitting ? "Oppretter…" : "Opprett"}
        </Button>
        <Button type="button" variant="ghost" onClick={onCancel} className="h-11 rounded-xl font-semibold text-muted-foreground">
          Avbryt
        </Button>
      </div>
    </form>
  )
}