"use client";

import { useEffect, useState } from "react";
import { ConstructionEta } from "@/components/frontend/baseManagement/ConstructionEta";

interface ConstructionMaterial {
  name: string;
  required: number;
  delivered: number;
}

interface ConstructionPanelProps {
  status: "awaiting_materials" | "building" | "complete" | null;
  startedAt: string | null;
  completesAt: string | null;
  durationMinutes: number | null;
  materials: ConstructionMaterial[];
  crew?: { required: number; effective: number } | null;
}

const STATUS_LABELS: Record<string, { label: string; className: string }> = {
  awaiting_materials: {
    label: "Awaiting Materials",
    className: "border-amber-500/40 bg-amber-500/10 text-amber-300",
  },
  building: {
    label: "Building",
    className: "border-blue-500/40 bg-blue-500/10 text-blue-300",
  },
  complete: {
    label: "Operational",
    className: "border-emerald-500/40 bg-emerald-500/10 text-emerald-300",
  },
};

function progressPct(startedAt: string | null, completesAt: string | null, nowMs: number): number {
  if (!startedAt || !completesAt) return 0;
  const start = new Date(startedAt).getTime();
  const end = new Date(completesAt).getTime();
  if (!Number.isFinite(start) || !Number.isFinite(end) || end <= start) return 0;
  const ratio = (nowMs - start) / (end - start);
  if (!Number.isFinite(ratio)) return 0;
  return Math.min(100, Math.max(0, Math.round(ratio * 100)));
}

export function ConstructionPanel({
  status,
  startedAt,
  completesAt,
  durationMinutes,
  materials,
  crew,
}: ConstructionPanelProps) {
  const [nowMs, setNowMs] = useState(() => Date.now());

  useEffect(() => {
    const timer = setInterval(() => setNowMs(Date.now()), 1000);
    return () => clearInterval(timer);
  }, []);

  if (!status || status === "complete") return null;

  const statusInfo = STATUS_LABELS[status] ?? STATUS_LABELS.awaiting_materials;
  const allDelivered = materials.every((material) => material.delivered >= material.required);
  const pct = status === "building" ? progressPct(startedAt, completesAt, nowMs) : 0;

  const crewRequired = crew?.required ?? 0;
  const crewEffective = crew?.effective ?? 0;
  const crewFactor = crewRequired > 0 ? Math.min(1, crewEffective / crewRequired) : 1;
  const crewLine =
    crewRequired > 0
      ? crewEffective <= 0
        ? {
            text:
              status === "building"
                ? "No crew assigned: construction is crawling at minimum speed."
                : "No crew assigned: construction cannot start once materials arrive.",
            className: "text-amber-300",
          }
        : crewFactor < 1
          ? {
              text: `Crew ${crewEffective.toLocaleString()} / ${crewRequired.toLocaleString()}: understaffed, building at ${Math.round(crewFactor * 100)}% speed.`,
              className: "text-amber-300",
            }
          : {
              text: `Crew ${crewEffective.toLocaleString()} / ${crewRequired.toLocaleString()}: full build speed.`,
              className: "text-emerald-400",
            }
      : null;

  return (
    <div className="rounded-lg border border-border p-5 flex flex-col gap-3">
      <div className="flex items-center justify-between gap-2">
        <h2 className="text-sm font-semibold">Construction</h2>
        <span
          className={`rounded-sm border px-2 py-0.5 text-xs uppercase tracking-wide ${statusInfo.className}`}
        >
          {statusInfo.label}
        </span>
      </div>

      {status === "building" && (
        <div className="flex flex-col gap-1">
          <div className="flex justify-between text-xs text-muted-foreground">
            <span>
              Build time {durationMinutes != null ? `${durationMinutes.toLocaleString()} min` : ""}
            </span>
            <span>{pct}%</span>
          </div>
          <div className="h-1.5 w-full overflow-hidden rounded-full bg-muted">
            <div className="h-full rounded-full bg-blue-400" style={{ width: `${pct}%` }} />
          </div>
          <div className="flex justify-end text-xs tabular-nums text-muted-foreground">
            <ConstructionEta completesAt={completesAt} />
          </div>
        </div>
      )}

      {status === "awaiting_materials" && (
        <p className="text-xs text-muted-foreground">
          Ship the required materials to this site. Construction starts automatically once
          everything has arrived.
        </p>
      )}

      {crewLine && <p className={`text-xs ${crewLine.className}`}>{crewLine.text}</p>}

      <div className="flex flex-col gap-1.5">
        {materials.map((material) => {
          const met = material.delivered >= material.required;
          return (
            <div
              key={material.name}
              className="flex items-center justify-between gap-2 rounded-md bg-muted/40 px-3 py-1.5 text-sm"
            >
              <span>{material.name}</span>
              <span className={`tabular-nums ${met ? "text-emerald-400" : "text-amber-300"}`}>
                {material.delivered.toLocaleString()} / {material.required.toLocaleString()}
              </span>
            </div>
          );
        })}
        {materials.length === 0 && (
          <p className="text-xs text-muted-foreground">No materials required by this blueprint.</p>
        )}
      </div>

      {status === "awaiting_materials" && !allDelivered && (
        <p className="text-xs text-muted-foreground">
          {materials.filter((material) => material.delivered < material.required).length} material
          type(s) still missing.
        </p>
      )}
    </div>
  );
}