import { Card, Skeleton, Text } from "@mantine/core";
import type { LucideIcon } from "lucide-react";
import type { ElementType, ReactNode } from "react";
import { Link } from "react-router-dom";

import { cn } from "@/lib/utils";

export interface KpiItem {
  label: string;
  value: ReactNode;
  /** Optional leading icon rendered in a tinted chip. */
  icon?: LucideIcon;
  /** Secondary line under the label (e.g. a unit or comparison). */
  hint?: string;
  /**
   * Mantine color name for the icon chip (e.g. "edr-green", "red", "yellow").
   * Defaults to the brand green so a strip reads as uniform unless a page opts
   * into semantic tints.
   */
  color?: string;
  /**
   * Optional change vs a prior period, rendered as a ▲/▼ chip next to the value
   * (green up, red down, muted zero). E.g. today's count minus yesterday's.
   */
  delta?: number;
  /**
   * Optional route the cell links to — its detail view. When set the cell
   * becomes clickable (pointer, hover tint); when absent it stays static.
   */
  href?: string;
}

export interface KpiStripProps {
  items: KpiItem[];
  /** Show skeletons in place of values while data loads. */
  loading?: boolean;
}

/**
 * A single bordered card divided into up to five KPI cells:
 * `[ kpi | kpi | kpi ]`. Hairline dividers separate cells (vertical on wide
 * screens, horizontal when they wrap). Surface, border and shadow all come from
 * the theme — no per-cell backgrounds, gradients or custom shadows.
 */
export function KpiStrip({ items, loading = false }: KpiStripProps) {
  // The spec caps a strip at five cells; extra items are dropped rather than
  // silently overflowing into an unreadable row.
  const cells = items.slice(0, 5);

  return (
    <Card withBorder shadow="sm" p={0} className="overflow-hidden">
      <div className="flex flex-col sm:flex-row">
        {cells.map((item, index) => {
          const Icon = item.icon;
          const color = item.color ?? "edr-green";
          // A cell with an href becomes a link to its detail; without one it
          // stays a plain div. Same layout classes either way.
          const Cell: ElementType = item.href ? Link : "div";
          const linkProps = item.href
            ? { to: item.href, "aria-label": `${item.label} — view detail` }
            : {};
          return (
            <Cell
              key={item.label}
              {...(linkProps as Record<string, unknown>)}
              className={cn(
                "flex flex-1 items-center gap-3 px-5 py-4",
                index > 0 &&
                  "border-t border-edr-border sm:border-l sm:border-t-0",
                item.href &&
                  "cursor-pointer no-underline transition-colors hover:bg-gray-50 focus-visible:bg-gray-50",
              )}
            >
              {Icon ? (
                <div
                  className="flex size-10 shrink-0 items-center justify-center rounded-lg"
                  style={{
                    background: `var(--mantine-color-${color}-1)`,
                    color: `var(--mantine-color-${color}-7)`,
                  }}
                >
                  <Icon size={20} strokeWidth={2} />
                </div>
              ) : null}

              <div style={{ minWidth: 0 }}>
                {loading ? (
                  <Skeleton height={26} width={72} radius="sm" my={2} />
                ) : (
                  <div className="flex items-baseline gap-2">
                    <Text
                      fw={800}
                      fz={24}
                      lh={1.05}
                      c="edr-text"
                      style={{ letterSpacing: "-0.02em" }}
                      truncate
                    >
                      {item.value}
                    </Text>
                    {item.delta != null && item.delta !== 0 ? (
                      <Text
                        component="span"
                        fz="xs"
                        fw={700}
                        c={item.delta > 0 ? "edr-green.7" : "red.7"}
                        style={{
                          whiteSpace: "nowrap",
                          background:
                            item.delta > 0
                              ? "var(--mantine-color-edr-green-0)"
                              : "var(--mantine-color-red-0)",
                          borderRadius: 999,
                          padding: "1px 7px",
                        }}
                      >
                        {item.delta > 0 ? "▲" : "▼"}
                        {Math.abs(item.delta)}
                      </Text>
                    ) : null}
                  </div>
                )}
                <Text size="xs" fw={600} c="edr-muted" truncate>
                  {item.label}
                  {item.hint ? ` · ${item.hint}` : ""}
                </Text>
              </div>
            </Cell>
          );
        })}
      </div>
    </Card>
  );
}

export default KpiStrip;