// Button Component - Material Design 3
// =====================================
// Implements M3 button specifications using official M3 tokens
// https://m3.material.io/components/buttons/specs

@use '../tokens' as m3;

// Base button styles
.button {
  // Layout
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  border-radius: m3.$corner-full;
  cursor: pointer;
  text-decoration: none;
  overflow: hidden;
  user-select: none;
  vertical-align: middle;
  -webkit-appearance: none;

  // Typography (M3 label-large)
  @include m3.typography(label-large);

  // Transitions
  transition:
    background-color m3.$motion-duration-short4 m3.$motion-easing-standard,
    box-shadow m3.$motion-duration-short4 m3.$motion-easing-standard,
    border-color m3.$motion-duration-short4 m3.$motion-easing-standard;

  // Touch target (48px minimum)
  &::after {
    content: '';
    position: absolute;
    inset: 50% auto auto 50%;
    transform: translate(-50%, -50%);
    width: 48px;
    height: 48px;
  }

  // Focus ring
  &:focus-visible {
    outline: 2px solid m3.$primary;
    outline-offset: 2px;
  }

  // Disabled base state
  &:disabled {
    @include m3.disabled;
  }

  // Icon sizing
  .icon {
    display: inline-flex;
    font-size: 1.125rem;
    width: 1.125rem;
    height: 1.125rem;
  }

  // ============================================
  // Size Variants
  // ============================================

  &--small {
    height: 32px;
    padding: 0 16px;
    font-size: 0.75rem;

    .icon {
      font-size: 1rem;
      width: 1rem;
      height: 1rem;
    }
  }

  &--medium {
    height: 40px;
    padding: 0 24px;
  }

  &--large {
    height: 48px;
    padding: 0 32px;
    font-size: 1rem;

    .icon {
      font-size: 1.25rem;
      width: 1.25rem;
      height: 1.25rem;
    }
  }

  // ============================================
  // Filled Button (High Emphasis)
  // ============================================

  &--filled {
    background: m3.$primary;
    color: m3.$on-primary;

    &:hover:not(:disabled) {
      // M3: state layer with on-primary color at hover opacity
      background: color-mix(
        in srgb,
        m3.$primary calc(100% - 8%),
        m3.$on-primary
      );
    }

    &:focus-visible:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary calc(100% - 12%),
        m3.$on-primary
      );
    }

    &:active:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary calc(100% - 12%),
        m3.$on-primary
      );
    }

    &:disabled {
      background: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-container-opacity * 100%},
        transparent
      );
      color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-content-opacity * 100%},
        transparent
      );
    }
  }

  // ============================================
  // Outlined Button (Medium Emphasis)
  // ============================================

  &--outlined {
    background: transparent;
    color: m3.$primary;
    border: 1px solid m3.$outline;

    &:hover:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 8%,
        transparent
      );
    }

    &:focus-visible:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 12%,
        transparent
      );
      border-color: m3.$primary;
    }

    &:active:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 12%,
        transparent
      );
    }

    &:disabled {
      color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-content-opacity * 100%},
        transparent
      );
      border-color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-container-opacity * 100%},
        transparent
      );
    }
  }

  // ============================================
  // Text Button (Low Emphasis)
  // ============================================

  &--text {
    background: transparent;
    color: m3.$primary;
    padding: 0 12px;

    &:hover:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 8%,
        transparent
      );
    }

    &:focus-visible:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 12%,
        transparent
      );
    }

    &:active:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$primary 12%,
        transparent
      );
    }

    &:disabled {
      color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-content-opacity * 100%},
        transparent
      );
    }
  }

  // ============================================
  // Tonal Button (Secondary Container)
  // ============================================

  &--tonal {
    background: m3.$secondary-container;
    color: m3.$on-secondary-container;

    &:hover:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$secondary-container calc(100% - 8%),
        m3.$on-secondary-container
      );
    }

    &:focus-visible:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$secondary-container calc(100% - 12%),
        m3.$on-secondary-container
      );
    }

    &:active:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$secondary-container calc(100% - 12%),
        m3.$on-secondary-container
      );
    }

    &:disabled {
      background: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-container-opacity * 100%},
        transparent
      );
      color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-content-opacity * 100%},
        transparent
      );
    }
  }

  // ============================================
  // Elevated Button (With Shadow)
  // ============================================

  &--elevated {
    background: m3.$surface-container-low;
    color: m3.$primary;
    box-shadow: m3.$elevation-level1;

    &:hover:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$surface-container-low calc(100% - 8%),
        m3.$primary
      );
      box-shadow: m3.$elevation-level2;
    }

    &:focus-visible:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$surface-container-low calc(100% - 12%),
        m3.$primary
      );
      box-shadow: m3.$elevation-level1;
    }

    &:active:not(:disabled) {
      background: color-mix(
        in srgb,
        m3.$surface-container-low calc(100% - 12%),
        m3.$primary
      );
      box-shadow: m3.$elevation-level1;
    }

    &:disabled {
      background: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-container-opacity * 100%},
        transparent
      );
      color: color-mix(
        in srgb,
        m3.$on-surface #{m3.$disabled-content-opacity * 100%},
        transparent
      );
      box-shadow: m3.$elevation-level0;
    }
  }
}