import type { ReactNode } from "react";
import { Ionicons } from "@expo/vector-icons";
import {
  ActivityIndicator,
  Pressable,
  View,
  type PressableProps,
  type StyleProp,
  type ViewStyle,
} from "react-native";
import { Text } from "@/components/ui/Text";
import { colors, radii, shadows } from "@/lib/theme";

type Variant = "primary" | "brand" | "dark" | "outline" | "ghost" | "soft" | "danger";
type Size = "sm" | "md" | "lg";

type Props = Omit<PressableProps, "style"> & {
  title: string;
  variant?: Variant;
  size?: Size;
  icon?: keyof typeof Ionicons.glyphMap;
  iconRight?: keyof typeof Ionicons.glyphMap;
  loading?: boolean;
  fullWidth?: boolean;
  elevated?: boolean;
  style?: StyleProp<ViewStyle>;
};

const skins: Record<Variant, { bg: string; fg: string; border: string }> = {
  // Lime fill with ink text: on-brand and far more legible than white-on-lime.
  primary: { bg: colors.brand, fg: colors.ink, border: "transparent" },
  brand: { bg: colors.brand, fg: colors.ink, border: "transparent" },
  dark: { bg: colors.ink, fg: colors.surface, border: "transparent" },
  outline: { bg: "transparent", fg: colors.ink, border: colors.line },
  ghost: { bg: "transparent", fg: colors.ink, border: "transparent" },
  soft: { bg: colors.brandSoft, fg: colors.brandText, border: "transparent" },
  danger: { bg: colors.dangerSoft, fg: colors.danger, border: "transparent" },
};

const sizing: Record<Size, { py: number; px: number; gap: number; icon: number }> = {
  sm: { py: 9, px: 14, gap: 6, icon: 15 },
  md: { py: 13, px: 18, gap: 8, icon: 17 },
  lg: { py: 16, px: 22, gap: 9, icon: 19 },
};

export function Button({
  title,
  variant = "primary",
  size = "lg",
  icon,
  iconRight,
  loading,
  disabled,
  fullWidth = true,
  elevated,
  style,
  ...rest
}: Props) {
  const skin = skins[variant];
  const dims = sizing[size];
  const inactive = disabled || loading;

  return (
    <Pressable
      disabled={inactive}
      style={({ pressed }) => [
        {
          backgroundColor: inactive ? colors.surfaceAlt : skin.bg,
          borderColor: skin.border,
          borderWidth: variant === "outline" ? 1.5 : 0,
          borderRadius: radii.pill,
          paddingVertical: dims.py,
          paddingHorizontal: dims.px,
          flexDirection: "row",
          alignItems: "center",
          justifyContent: "center",
          gap: dims.gap,
          alignSelf: fullWidth ? "stretch" : "flex-start",
          opacity: pressed ? 0.88 : 1,
          transform: [{ scale: pressed ? 0.99 : 1 }],
        },
        elevated && !inactive && shadows.sm,
        style,
      ]}
      {...rest}
    >
      {loading ? (
        <ActivityIndicator size="small" color={inactive ? colors.subtle : skin.fg} />
      ) : (
        <>
          {icon ? (
            <Ionicons
              name={icon}
              size={dims.icon}
              color={inactive ? colors.subtle : skin.fg}
            />
          ) : null}
          <Text
            variant={size === "sm" ? "label" : "h3"}
            color={inactive ? colors.subtle : skin.fg}
          >
            {title}
          </Text>
          {iconRight ? (
            <Ionicons
              name={iconRight}
              size={dims.icon}
              color={inactive ? colors.subtle : skin.fg}
            />
          ) : null}
        </>
      )}
    </Pressable>
  );
}

/** Circular icon button used in headers and cards. */
export function IconButton({
  icon,
  onPress,
  size = 40,
  tone = "surface",
  color,
  accessibilityLabel,
}: {
  icon: keyof typeof Ionicons.glyphMap;
  onPress?: () => void;
  size?: number;
  tone?: "surface" | "brand" | "dark" | "plain";
  color?: string;
  accessibilityLabel?: string;
}) {
  const bg =
    tone === "brand"
      ? colors.brand
      : tone === "dark"
        ? colors.ink
        : tone === "plain"
          ? "transparent"
          : colors.surface;
  const fg = color ?? (tone === "dark" ? colors.surface : colors.ink);

  return (
    <Pressable
      accessibilityRole="button"
      accessibilityLabel={accessibilityLabel}
      onPress={onPress}
      style={({ pressed }) => [
        {
          width: size,
          height: size,
          borderRadius: size / 2,
          backgroundColor: bg,
          alignItems: "center",
          justifyContent: "center",
          opacity: pressed ? 0.7 : 1,
        },
        tone === "surface" && { borderWidth: 1, borderColor: colors.line },
      ]}
    >
      <Ionicons name={icon} size={size * 0.46} color={fg} />
    </Pressable>
  );
}

/** Small round "+" affordance on product cards. */
export function AddButton({
  onPress,
  disabled,
  size = 34,
}: {
  onPress?: () => void;
  disabled?: boolean;
  size?: number;
}) {
  return (
    <Pressable
      accessibilityRole="button"
      accessibilityLabel="Add to cart"
      disabled={disabled}
      onPress={onPress}
      hitSlop={8}
      style={({ pressed }) => ({
        width: size,
        height: size,
        borderRadius: size / 2,
        backgroundColor: disabled ? colors.surfaceAlt : colors.brand,
        alignItems: "center",
        justifyContent: "center",
        opacity: pressed ? 0.8 : 1,
      })}
    >
      <Ionicons name="add" size={size * 0.55} color={disabled ? colors.subtle : colors.ink} />
    </Pressable>
  );
}

export function ButtonRow({ children }: { children: ReactNode }) {
  return <View style={{ flexDirection: "row", gap: 10 }}>{children}</View>;
}