"use client";

import Link from "next/link";
import { useRef, useState, useTransition } from "react";
import type { Project, ProjectExpertScore, RikxRonde } from "../../../lib/db";
import { PROJECT_STATUSES } from "../../../lib/projectStatus";
import {
  BONUS_MALUS_OPTIONS,
  EXPERT_COUNT,
  EXPERT_CRITERIA,
  calculateRikx,
  type ExpertScore,
} from "../../../lib/rikxCalculatie";
import { parseProjectPlanJson } from "../../../lib/projectPlan";
import { setRikxCalculatie, updateProject } from "../actions";
import { ProjectPlanFields } from "./ProjectPlanFields";

const inputClass =
  "w-full h-10 rounded-lg border border-zinc-300 dark:border-zinc-700 bg-white dark:bg-zinc-800 px-3 text-sm text-zinc-900 dark:text-zinc-100 focus:outline-none focus:ring-2 focus:ring-rikx-orange";
const labelClass = "text-sm font-medium text-zinc-700 dark:text-zinc-300";
const cardClass = "bg-white dark:bg-zinc-900 rounded-xl border border-zinc-200 dark:border-zinc-800 p-6";

function toNumber(value: FormDataEntryValue | null): number | null {
  if (typeof value !== "string" || value.trim() === "") return null;
  const n = Number(value.replace(",", "."));
  return Number.isFinite(n) ? n : null;
}

function rondeById(rondes: RikxRonde[], id: number | null) {
  return rondes.find((r) => r.id === id) ?? null;
}

function readInput(form: HTMLFormElement, rondes: RikxRonde[]) {
  const fd = new FormData(form);
  const ronde = rondeById(rondes, Number(fd.get("ronde_id")) || null);
  return {
    ronde_id: ronde?.id ?? null,
    projectkosten: toNumber(fd.get("projectkosten")),
    deelnemers_werk: toNumber(fd.get("deelnemers_werk")),
    deelnemers_skills: toNumber(fd.get("deelnemers_skills")),
    financiering_extern_pct: toNumber(fd.get("financiering_extern_pct")),
    bonus_malus: (fd.get("bonus_malus") as string) || null,
    rikx_waarde: ronde?.rikx_waarde ?? null,
    rikx_prijs: ronde?.rikx_prijs ?? null,
    expert_scores: Array.from({ length: EXPERT_COUNT }, (_, i) =>
      Object.fromEntries(EXPERT_CRITERIA.map((c) => [c.id, toNumber(fd.get(`expert_${i + 1}_${c.id}`))]))
    ) as ExpertScore[],
  };
}

const nl = (digits: number) => new Intl.NumberFormat("nl-NL", { maximumFractionDigits: digits });
const euro = new Intl.NumberFormat("nl-NL", { style: "currency", currency: "EUR" });
const fmt = (v: number | null, kind: "getal" | "euro" | "geheel" = "getal") =>
  v === null ? "—" : kind === "euro" ? euro.format(v) : nl(kind === "geheel" ? 0 : 2).format(v);

function Field({
  label,
  hint,
  children,
}: {
  label: string;
  hint?: string;
  children: React.ReactNode;
}) {
  return (
    <label className="flex flex-col gap-1">
      <span className={labelClass}>{label}</span>
      {children}
      {hint && <span className="text-xs text-zinc-500">{hint}</span>}
    </label>
  );
}

function StepHeading({ step, title, description }: { step: number; title: string; description: string }) {
  return (
    <div className="flex items-start gap-3 mb-5">
      <span className="flex items-center justify-center w-7 h-7 shrink-0 rounded-full bg-rikx-orange text-white text-sm font-semibold">
        {step}
      </span>
      <div>
        <h2 className="font-semibold text-zinc-900 dark:text-zinc-100">{title}</h2>
        <p className="text-sm text-zinc-500">{description}</p>
      </div>
    </div>
  );
}

export function ProjectDetailForm({
  project,
  expertScores,
  rondes,
}: {
  project: Project;
  expertScores: ProjectExpertScore[];
  rondes: RikxRonde[];
}) {
  const formRef = useRef<HTMLFormElement>(null);
  const [calcOn, setCalcOn] = useState(project.rikx_calculatie_aan === 1);
  const [pending, startTransition] = useTransition();
  const initialRonde = rondeById(rondes, project.ronde_id);
  const [input, setInput] = useState(() => ({
    ronde_id: initialRonde?.id ?? null,
    projectkosten: project.projectkosten,
    deelnemers_werk: project.deelnemers_werk,
    deelnemers_skills: project.deelnemers_skills,
    financiering_extern_pct: project.financiering_extern_pct,
    bonus_malus: project.bonus_malus,
    rikx_waarde: initialRonde?.rikx_waarde ?? null,
    rikx_prijs: initialRonde?.rikx_prijs ?? null,
    expert_scores: Array.from({ length: EXPERT_COUNT }, (_, i) => {
      const s = expertScores.find((e) => e.expert === i + 1);
      return {
        duur_impact: s?.duur_impact ?? null,
        levensdomeinen: s?.levensdomeinen ?? null,
        basissituatie: s?.basissituatie ?? null,
      };
    }),
  }));
  const result = calculateRikx(input);
  const ronde = rondeById(rondes, input.ronde_id);

  function toggleCalc() {
    const next = !calcOn;
    setCalcOn(next);
    startTransition(() => setRikxCalculatie(project.id, next));
  }

  const results: { label: string; value: string; strong?: boolean }[] = [
    { label: "N-score", value: fmt(result.n_score) },
    { label: "Scale", value: fmt(result.scale, "geheel") },
    { label: "Impactscore M", value: fmt(result.impactscore_m) },
    { label: "IS +/- BM", value: fmt(result.is_bm) },
    { label: "Impactwaarde", value: fmt(result.impactwaarde) },
    { label: "Minus cofinanciering", value: fmt(result.minus_cofinanciering) },
    { label: "I - cofin", value: fmt(result.i_cofin) },
    { label: "Kosten/impact", value: fmt(result.kosten_impact) },
    { label: "Totale impactwaarde", value: fmt(result.totale_impactwaarde, "euro"), strong: true },
    { label: "Totaal aantal Rikx", value: fmt(result.totaal_aantal_rikx), strong: true },
    { label: "Meerwaarde", value: fmt(result.meerwaarde, "euro"), strong: true },
    { label: "Efficiëntiewaarde", value: fmt(result.efficientie_waarde), strong: true },
  ];

  return (
    <form
      ref={formRef}
      action={updateProject}
      onInput={() => formRef.current && setInput(readInput(formRef.current, rondes))}
      className="flex flex-col gap-6"
    >
      <input type="hidden" name="id" value={project.id} />

      <section className={`${cardClass} grid grid-cols-1 sm:grid-cols-3 gap-4`}>
        <Field label="Projectnaam">
          <input name="name" required defaultValue={project.name} className={inputClass} />
        </Field>
        <Field label="Status">
          <select name="status" defaultValue={project.status} className={inputClass}>
            {PROJECT_STATUSES.map((s) => (
              <option key={s.id} value={s.id}>
                {s.label}
              </option>
            ))}
          </select>
        </Field>
        <Field label="Rikx Ronde">
          <select name="ronde_id" defaultValue={project.ronde_id ?? ""} className={inputClass}>
            <option value="">Geen ronde</option>
            {rondes.map((r) => (
              <option key={r.id} value={r.id}>
                {r.label}
              </option>
            ))}
          </select>
        </Field>
      </section>

      <section className={cardClass}>
        <StepHeading step={1} title="Project plan" description="In te vullen door de sociaal ondernemer." />
        <ProjectPlanFields project={project} plan={parseProjectPlanJson(project.project_plan)} />
      </section>

      <div className="flex items-center justify-between gap-4 rounded-xl border border-zinc-200 dark:border-zinc-800 bg-white dark:bg-zinc-900 px-6 py-4">
        <div>
          <p className="font-medium text-zinc-900 dark:text-zinc-100">Rikx calculatie</p>
          <p className="text-sm text-zinc-500">Toon de waardebepaling volgens de Rikx-rekenmethode.</p>
        </div>
        <button
          type="button"
          role="switch"
          aria-checked={calcOn}
          aria-label="Rikx calculatie tonen"
          onClick={toggleCalc}
          disabled={pending}
          className={`relative inline-flex h-7 w-12 shrink-0 items-center rounded-full transition-colors disabled:opacity-60 ${
            calcOn ? "bg-rikx-orange" : "bg-zinc-300 dark:bg-zinc-700"
          }`}
        >
          <span
            className={`inline-block h-5 w-5 rounded-full bg-white shadow transition-transform ${
              calcOn ? "translate-x-6" : "translate-x-1"
            }`}
          />
        </button>
      </div>

      {/* Verborgen in plaats van weggelaten, zodat de waarden bij opslaan bewaard blijven. */}
      <section className={cardClass} hidden={!calcOn}>
        <StepHeading
          step={2}
          title="Rikx calculatie"
          description="Waardebepaling door het expertteam en Rikx. Uitkomsten worden live berekend."
        />

        <h3 className="text-sm font-semibold text-zinc-900 dark:text-zinc-100 mb-2">Expertscores (1–10)</h3>
        <div className="overflow-x-auto mb-6">
          <table className="w-full text-sm">
            <thead>
              <tr className="text-zinc-500">
                <th className="text-left font-medium py-2 pr-3">Criterium</th>
                {Array.from({ length: EXPERT_COUNT }, (_, i) => (
                  <th key={i} className="text-left font-medium py-2 px-1 min-w-24">
                    Expert {i + 1}
                  </th>
                ))}
              </tr>
            </thead>
            <tbody>
              {EXPERT_CRITERIA.map((c) => (
                <tr key={c.id}>
                  <td className="py-1 pr-3 text-zinc-700 dark:text-zinc-300 whitespace-nowrap">{c.label}</td>
                  {Array.from({ length: EXPERT_COUNT }, (_, i) => (
                    <td key={i} className="py-1 px-1">
                      <input
                        name={`expert_${i + 1}_${c.id}`}
                        type="number"
                        min={1}
                        max={10}
                        step="0.5"
                        aria-label={`${c.label}, expert ${i + 1}`}
                        defaultValue={input.expert_scores[i][c.id] ?? ""}
                        className={inputClass}
                      />
                    </td>
                  ))}
                </tr>
              ))}
            </tbody>
          </table>
          <p className="text-xs text-zinc-500 mt-1">Voorlopig handmatig; met Module 4 vullen de experts dit zelf in.</p>
        </div>

        <div className="grid grid-cols-1 sm:grid-cols-2 gap-4 mb-6">
          <Field label="Bonus / Malus" hint="Collectief oordeel van de experts: ++ 1,2 · + 1,1 · geen 1,0 · - 0,9 · -- 0,8">
            <select name="bonus_malus" defaultValue={project.bonus_malus ?? ""} className={inputClass}>
              {BONUS_MALUS_OPTIONS.map((o) => (
                <option key={o.label} value={o.id}>
                  {o.label}
                </option>
              ))}
            </select>
          </Field>
          <div className="flex flex-col gap-1">
            <span className={labelClass}>Rikx waarde en Rikx prijs</span>
            {ronde ? (
              <p className="h-10 flex items-center gap-4 rounded-lg bg-zinc-50 dark:bg-zinc-800/50 px-3 text-sm tabular-nums text-zinc-800 dark:text-zinc-200">
                <span>Waarde {fmt(ronde.rikx_waarde)}</span>
                <span>Prijs {fmt(ronde.rikx_prijs, "euro")}</span>
              </p>
            ) : (
              <p className="h-10 flex items-center rounded-lg bg-zinc-50 dark:bg-zinc-800/50 px-3 text-sm text-zinc-500">
                Kies eerst een Rikx Ronde
              </p>
            )}
            <span className="text-xs text-zinc-500">
              Uit de Rikx Ronde{ronde ? ` "${ronde.label}"` : ""}; aan te passen bij{" "}
              <Link href="/rondes" className="underline hover:text-rikx-orange-dark">
                Rikx rondes
              </Link>
              .
            </span>
          </div>
        </div>

        <h3 className="text-sm font-semibold text-zinc-900 dark:text-zinc-100 mb-2">Uitkomsten</h3>
        <dl className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-x-6 rounded-lg bg-zinc-50 dark:bg-zinc-800/50 px-4 py-2">
          {results.map((r) => (
            <div key={r.label} className="flex items-center justify-between gap-4 py-2 border-b border-zinc-200/70 dark:border-zinc-700/70">
              <dt className="text-sm text-zinc-600 dark:text-zinc-400">{r.label}</dt>
              <dd className={`text-sm tabular-nums ${r.strong ? "font-semibold text-zinc-900 dark:text-zinc-100" : "text-zinc-800 dark:text-zinc-200"}`}>
                {r.value}
              </dd>
            </div>
          ))}
        </dl>
      </section>

      <div className="flex gap-3">
        <button
          type="submit"
          className="rounded-lg bg-rikx-maroon hover:bg-rikx-maroon-light px-5 py-2 text-sm font-medium text-white transition-colors"
        >
          Opslaan
        </button>
        <Link
          href="/projecten"
          className="rounded-lg border border-zinc-300 dark:border-zinc-700 px-5 py-2 text-sm text-zinc-700 dark:text-zinc-300 hover:bg-zinc-100 dark:hover:bg-zinc-800 transition-colors"
        >
          Annuleren
        </Link>
      </div>
    </form>
  );
}