import { Pressable, StyleSheet, Text, TextInput, View, type TextInputProps, type ViewStyle } from "react-native";
import { C, radius, shadow, space, type } from "../lib/theme";

/**
 * Screen background + consistent gutter. Every screen sits on the grouped
 * background so white cards read as raised paper.
 */
export function Screen({ children, style }: { children: React.ReactNode; style?: ViewStyle }) {
  return <View style={[u.screen, style]}>{children}</View>;
}

/**
 * Large in-content heading. Nav-bar titles are tiny and centred; Things puts
 * the screen name in the content at display size, which is what gives each
 * screen its sense of place.
 */
export function Title({ children, count }: { children: React.ReactNode; count?: number }) {
  return (
    <View style={u.titleRow}>
      <Text style={u.title}>{children}</Text>
      {count !== undefined && count > 0 && <Text style={u.titleCount}>{count}</Text>}
    </View>
  );
}

/** Small caps label above a group. Sentence case — SHOUTING CAPS reads dated. */
export function SectionHeader({ children, tone }: { children: React.ReactNode; tone?: string }) {
  return <Text style={[u.sectionHeader, !!tone && { color: tone }]}>{children}</Text>;
}

/**
 * Rounded white group. Rows inside are separated by inset hairlines rather
 * than full-bleed dividers, so the card keeps a clean silhouette.
 */
export function Card({ children, style }: { children: React.ReactNode; style?: ViewStyle }) {
  return <View style={[u.card, style]}>{children}</View>;
}

/** Inset hairline for use between rows inside a `Card`. */
export function Separator({ inset = 0 }: { inset?: number }) {
  return <View style={[u.separator, { marginLeft: inset }]} />;
}

/** Compact count/status pill. */
export function Pill({ label, tone }: { label: string; tone?: string }) {
  return (
    <View style={[u.pill, !!tone && { backgroundColor: `${tone}18` }]}>
      <Text style={[u.pillText, !!tone && { color: tone }]}>{label}</Text>
    </View>
  );
}

/** Centred empty state. One quiet line — no illustration, no exclamation. */
export function Empty({ children }: { children: React.ReactNode }) {
  return <Text style={u.empty}>{children}</Text>;
}

export function Field({ label, ...props }: TextInputProps & { label: string }) {
  return (
    <View style={{ marginBottom: space.lg }}>
      <Text style={u.label}>{label}</Text>
      <TextInput style={u.input} placeholderTextColor={C.muted} {...props} />
    </View>
  );
}

export function Chips<T extends string>({
  label,
  options,
  value,
  onChange,
  labels,
}: {
  label: string;
  options: T[];
  value: T | null;
  onChange: (v: T) => void;
  labels?: Record<string, string>;
}) {
  return (
    <View style={{ marginBottom: space.lg }}>
      <Text style={u.label}>{label}</Text>
      <View style={u.chipRow}>
        {options.map((o) => {
          const active = value === o;
          return (
            <Pressable
              key={o}
              style={({ pressed }) => [u.chip, active && u.chipActive, pressed && !active && u.chipPressed]}
              onPress={() => onChange(o)}
            >
              <Text style={[u.chipText, active && u.chipTextActive]}>{labels?.[o] ?? o}</Text>
            </Pressable>
          );
        })}
      </View>
    </View>
  );
}

export function Button({
  title,
  onPress,
  danger,
  secondary,
}: {
  title: string;
  onPress: () => void;
  danger?: boolean;
  secondary?: boolean;
}) {
  const variant = danger ? u.buttonDanger : secondary ? u.buttonSecondary : null;
  const textVariant = danger ? u.buttonTextDanger : secondary ? u.buttonTextSecondary : null;
  return (
    <Pressable
      style={({ pressed }) => [u.button, variant, pressed && { opacity: 0.75 }]}
      onPress={onPress}
    >
      <Text style={[u.buttonText, textVariant]}>{title}</Text>
    </Pressable>
  );
}

const u = StyleSheet.create({
  screen: { flex: 1, backgroundColor: C.bg },

  titleRow: {
    flexDirection: "row",
    alignItems: "center",
    gap: space.md,
    paddingHorizontal: space.lg,
    paddingTop: space.md,
    paddingBottom: space.lg,
  },
  title: { ...type.title, color: C.text },
  titleCount: { ...type.title, color: C.muted, fontWeight: "600" },

  sectionHeader: {
    ...type.section,
    color: C.textSecondary,
    paddingHorizontal: space.xs,
    paddingTop: space.xl,
    paddingBottom: space.sm,
  },

  card: {
    backgroundColor: C.surface,
    borderRadius: radius.lg,
    borderWidth: StyleSheet.hairlineWidth,
    borderColor: C.border,
    overflow: "hidden",
    ...shadow.card,
  },
  separator: { height: StyleSheet.hairlineWidth, backgroundColor: C.separator },

  pill: {
    paddingHorizontal: space.sm,
    paddingVertical: 3,
    borderRadius: radius.pill,
    backgroundColor: C.surface2,
  },
  pillText: { ...type.meta, color: C.textSecondary, fontWeight: "500" },

  empty: { color: C.muted, textAlign: "center", marginTop: 56, ...type.body },

  label: {
    ...type.section,
    color: C.textSecondary,
    marginBottom: space.sm,
  },
  input: {
    backgroundColor: C.surface,
    color: C.text,
    borderRadius: radius.md,
    borderWidth: StyleSheet.hairlineWidth,
    borderColor: C.border,
    paddingHorizontal: space.md,
    paddingVertical: space.md,
    fontSize: 16,
  },

  chipRow: { flexDirection: "row", flexWrap: "wrap", gap: space.sm },
  chip: {
    paddingVertical: space.sm,
    paddingHorizontal: space.lg - 2,
    borderRadius: radius.pill,
    backgroundColor: C.surface,
    borderWidth: StyleSheet.hairlineWidth,
    borderColor: C.border,
  },
  chipActive: { backgroundColor: C.accentSoft, borderColor: C.accent },
  chipPressed: { backgroundColor: C.surface2 },
  chipText: { ...type.chip, color: C.textSecondary },
  chipTextActive: { color: C.accent, fontWeight: "600" },

  button: {
    backgroundColor: C.accent,
    borderRadius: radius.md,
    paddingVertical: space.lg - 2,
    alignItems: "center",
    marginTop: space.sm,
    marginBottom: space.md,
  },
  buttonDanger: { backgroundColor: "transparent", borderWidth: StyleSheet.hairlineWidth, borderColor: C.danger },
  buttonSecondary: { backgroundColor: C.surface, borderWidth: StyleSheet.hairlineWidth, borderColor: C.border },
  buttonText: { fontSize: 16, fontWeight: "600", color: C.onAccent },
  buttonTextDanger: { color: C.danger },
  buttonTextSecondary: { color: C.text },
});