@use '@vialiq/flux-ui/styles/variables' as tokens;
@use '../styles/functions' as func;

@layer components {

// ─────────────────────────────────────────────────────────────────────────────
// vi-tabs — Container, tablist, SLIDING CURSOR, indicator, all variants
//
// Architecture:
//  • .vi-tabs__cursor  → absolutely positioned, slides between tabs (JS-positioned)
//                         Used by: pill, card, enclosed (the "selected surface")
//  • .vi-tabs__indicator → absolutely positioned thin line at bottom/side (JS-positioned)
//                          Used by: line, secondary (the "underline signal")
//
// The cursor element ALWAYS exists in the DOM. CSS on each variant controls
// whether it's visible (opacity, border-radius, shadow etc.)
// ─────────────────────────────────────────────────────────────────────────────


  .vi-tabs {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    position: relative;
  }

  .vi-tabs__scroll-btn {
    grid-area: 1 / 1;
    align-self: stretch;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px; // Wider to accommodate the gradient safely
    z-index: 10;
    border: none;
    color: var(--vi-tabs-text-color, #{tokens.$text-primary});
    cursor: pointer;
    transition: opacity 0.2s;
    
    &[disabled] {
      opacity: 0;
      pointer-events: none;
    }

    &:hover, &:focus-visible {
      color: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      outline: none;
    }

    &--left {
      justify-self: start;
      background: linear-gradient(to right, var(--vi-tabs-surface-primary, #{tokens.$layer-01}) 50%, transparent 100%);
      padding-right: 12px; // Push icon slightly left
    }

    &--right {
      justify-self: end;
      background: linear-gradient(to left, var(--vi-tabs-surface-primary, #{tokens.$layer-01}) 50%, transparent 100%);
      padding-left: 12px; // Push icon slightly right
    }
  }



// ─────────────────────────────────────────────────────────────────────────────
// Add Button
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs__add-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    flex-shrink: 0;
    background: transparent;
    border: none;
    border-radius: 50%;
    color: var(--vi-tabs-add-btn-color, #{tokens.$text-secondary});
    cursor: pointer;
    margin-left: 4px;
    outline: none;
    position: relative;
    transition: background-color 0.2s, color 0.2s;
    order: 9998; // Ensure it stays right before the More menu

    &::before {
      content: '';
      position: absolute;
      inset: 4px;
      border-radius: 50%;
      background-color: currentColor;
      opacity: 0;
      transition: opacity 0.2s;
    }

    &:hover::before,
    &:focus-visible::before {
      opacity: 0.08;
    }

    &:active::before {
      opacity: 0.12;
    }

    &:focus-visible {
      border-radius: #{func.to-rem(4px)}; // Square focus ring for accessibility
      outline: 2px solid var(--vi-tabs-focus-ring, #{tokens.$color-primary});
      outline-offset: 2px;
    }

    svg {
      position: relative; // Above the hover state
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
//  Shared tablist base
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs__tablist {
    grid-area: 1 / 1;
    position: relative;
    display: flex;
    flex-direction: row;
    align-items: stretch;
    gap: 0;
    // overflow: visible so overflow-menu dropdown is not clipped.
    // Each variant overrides this as needed.
    overflow: visible;
    min-width: 0;
  }

// ─────────────────────────────────────────────────────────────────────────────
// SLIDING CURSOR — the magic that makes this feel premium
//
// Positioned absolutely by JS. Each variant styles it differently.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs__cursor {
    position: absolute;
    top: 0;
    left: 0;
    pointer-events: none;
    opacity: 0;
    z-index: 0;

    // Transitions — fast out slow in, matching motion system
    transition:
      left    220ms cubic-bezier(0.4, 0, 0.2, 1),
      top     220ms cubic-bezier(0.4, 0, 0.2, 1),
      width   220ms cubic-bezier(0.4, 0, 0.2, 1),
      height  220ms cubic-bezier(0.4, 0, 0.2, 1),
      opacity 120ms ease;
  }

// ─────────────────────────────────────────────────────────────────────────────
// BOTTOM-LINE INDICATOR — for line / secondary variants
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs__indicator {
    position: absolute;
    bottom: 0;
    left: 0;
    height: var(--vi-tabs-indicator-thickness, 2px);
    width: 0;
    background: var(--vi-tabs-indicator-color, #{tokens.$color-primary});
    border-radius: #{func.to-rem(2px)} #{func.to-rem(2px)} 0 0;
    opacity: 0;
    pointer-events: none;
    z-index: 2;

    transition:
      left    220ms cubic-bezier(0.4, 0, 0.2, 1),
      width   220ms cubic-bezier(0.4, 0, 0.2, 1),
      top     220ms cubic-bezier(0.4, 0, 0.2, 1),
      height  220ms cubic-bezier(0.4, 0, 0.2, 1),
      opacity 120ms ease;
  }

// ─────────────────────────────────────────────────────────────────────────────
// VARIANT: line (default) — clean underline, minimal strip
//
// Design reference: Vercel, Linear, GitHub navigation
// Strip: barely-there border, no bg. Typography + indicator do the work.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--line {
    .vi-tabs__tablist {
      border-bottom: 1px solid var(--vi-tabs-border-color, #{tokens.$color-grey-200});
      background: transparent;
      padding: 0;
      gap: 0;
    }

    // Cursor hidden — line variant uses indicator only
    .vi-tabs__cursor {
      display: none;
    }

    // Indicator: solid 2px line
    .vi-tabs__indicator {
      bottom: -1px;
      height: 2px;
      background: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      border-radius: #{func.to-rem(2px)} #{func.to-rem(2px)} 0 0;
      box-shadow: 0 0 0 0 transparent; // no glow on line variant — keep clean
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// VARIANT: pill — segmented control / HeroUI / shadcn style
//
// Design reference: Apple iOS, shadcn/ui, HeroUI
// The cursor IS the active pill — white card that slides between tabs.
// Container: inset-shadow tray. Active: white card with shadow.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--pill {
    .vi-tabs__tablist {
      background: var(--vi-tabs-pill-bg, #{tokens.$color-grey-100});
      border: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      border-radius: #{func.to-rem(10px)};
      padding: var(--vi-tabs-spacing-xs, 4px);
      gap: var(--vi-tabs-gap-xs, 2px);
      // Inset shadow creates a "recessed tray" feel
      box-shadow: #{tokens.$shadow-inner-deep};
    }

    // The sliding white pill cursor
    .vi-tabs__cursor {
      display: block;
      inset: 4px auto;          // matches tablist padding
      border-radius: #{func.to-rem(7px)};
      background: var(--vi-tabs-surface-primary, #{tokens.$layer-01});
      // Multi-layer shadow for floating card feel
      box-shadow: #{tokens.$shadow-sm};
    }

    // Indicator hidden — cursor does selection work
    .vi-tabs__indicator {
      display: none;
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// VARIANT: secondary (M3 — sub-hierarchy, thinner indicator)
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--secondary {
    .vi-tabs__tablist {
      border-bottom: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      background: transparent;
      padding: 0;
    }

    .vi-tabs__cursor { display: none; }

    .vi-tabs__indicator {
      bottom: -1px;
      height: 2px;
      background: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      border-radius: #{func.to-rem(2px)} #{func.to-rem(2px)} 0 0;
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// VARIANT: card — browser-tab file-folder aesthetic
//
// Design reference: browser tabs, VS Code editor tabs
// Active tab: white surface merges with content area below.
// The cursor element becomes the white card + side borders.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--card {
    .vi-tabs__tablist {
      background: var(--vi-tabs-surface-secondary, #{tokens.$layer-02});
      border-bottom: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      padding: var(--vi-tabs-spacing-md-md-none, 8px 8px 0);
      gap: var(--vi-tabs-gap-sm, 4px);
      align-items: flex-end;
    }

    // The cursor is the active card surface
    .vi-tabs__cursor {
      $surface-color: var(--vi-tabs-surface-primary, #{tokens.$layer-01});
      display: block;
      border-radius: #{func.to-rem(8px)} #{func.to-rem(8px)} 0 0;
      background: $surface-color;
      border: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      border-bottom-color: $surface-color; // Merges with content below
      margin-top: 8px;
      box-shadow: #{tokens.$shadow-sm};
    }

    .vi-tabs__indicator { display: none; }
  }

// ─────────────────────────────────────────────────────────────────────────────
// VARIANT: enclosed — bordered box with shared header/content border
//
// Design reference: Mantine, Chakra UI enclosed tabs
// The entire component lives in a border box. Active tab has indicator only.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--enclosed {
    border: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
    border-radius: #{func.to-rem(10px)};
    overflow: clip;  // Enclosed: clip cursor inside rounded border box
    box-shadow: #{tokens.$shadow-sm};

    .vi-tabs__tablist {
      background: var(--vi-tabs-surface-secondary, #{tokens.$layer-02});
      border-bottom: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      padding: 0;
      gap: 0;
    }

    // Cursor: subtle active tab highlight within the enclosed strip
    .vi-tabs__cursor {
      display: block;
      top: 0;
      border-radius: 0;
      background: rgba(#{tokens.$color-primary}, 0.06);
      border-right: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      border-left: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
    }

    // Thin indicator at bottom of strip header
    .vi-tabs__indicator {
      bottom: 0;
      height: 3px;
      background: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      box-shadow: 0 0 8px color-mix(in srgb, #{tokens.$color-primary} 50%, transparent);
      border-radius: 0;
    }

    ::slotted(vi-tab) {
      border-right: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border}) !important;
      min-height: 44px !important;
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// ORIENTATION: vertical (sidebar settings pattern)
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--vertical {
    grid-template-columns: auto minmax(0, 1fr);
    align-items: stretch;

    .vi-tabs__tablist {
      flex-direction: column;
      align-items: stretch;
      background: var(--vi-tabs-surface-secondary, #{tokens.$layer-02});
      border-right: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
      border-bottom: none;
      padding: var(--vi-tabs-spacing-sm-xs, 6px 4px);
      min-width: 168px;
      gap: var(--vi-tabs-gap-xs, 2px);
    }

    // Cursor becomes the sliding bg highlight in vertical mode
    .vi-tabs__cursor {
      display: block;
      left: 4px !important;
      right: 4px;
      width: calc(100% - 8px) !important; // Override JS width — fills sidebar
      border-radius: #{func.to-rem(8px)};
      background: var(--vi-tabs-surface-primary, #{tokens.$layer-01});
      box-shadow: #{tokens.$shadow-sm};
    }

    // Vertical indicator — right edge accent line
    .vi-tabs__indicator {
      bottom: auto;
      top: 0;
      left: auto;
      right: 0;
      width: 3px !important;
      height: 0;
      border-radius: #{func.to-rem(3px)} 0 0 #{func.to-rem(3px)};
      background: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      box-shadow: 0 0 6px color-mix(in srgb, #{tokens.$color-primary} 40%, transparent);
    }

    ::slotted(vi-tab) {
      justify-content: flex-start !important;
      min-height: 40px !important;
      text-align: left !important;
    }

    &.vi-tabs--line ::slotted(vi-tab[active]) {
      background: var(--vi-tabs-surface-primary, #{tokens.$layer-01});
      border-radius: #{func.to-rem(8px)};
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// Reduced motion — respect system preferences
// ─────────────────────────────────────────────────────────────────────────────

  @media (prefers-reduced-motion: reduce) {
    .vi-tabs__cursor,
    .vi-tabs__indicator {
      transition: opacity 100ms ease;
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// OVERFLOW: scroll
//
// Tablist scrolls horizontally. Fade gradients hint at hidden content.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--overflow-scroll .vi-tabs__tablist {
    overflow-x: auto;
    overflow-y: hidden;
    scrollbar-width: none;
    &::-webkit-scrollbar { display: none; }

    // Premium visual indicator using mask-image to fade tabs at the scroll edges
    mask-image: linear-gradient(to right, transparent 0%, black 24px, black calc(100% - 24px), transparent 100%);
    -webkit-mask-image: linear-gradient(to right, transparent 0%, black 24px, black calc(100% - 24px), transparent 100%);
  
    // When at scroll start, hide left fade
    &[data-scroll-start] {
      mask-image: linear-gradient(to right, black 0%, black calc(100% - 24px), transparent 100%);
      -webkit-mask-image: linear-gradient(to right, black 0%, black calc(100% - 24px), transparent 100%);
    }

    // When at scroll end, hide right fade
    &[data-scroll-end] {
      mask-image: linear-gradient(to right, transparent 0%, black 24px, black 100%);
      -webkit-mask-image: linear-gradient(to right, transparent 0%, black 24px, black 100%);
    }

    // When no scroll possible, no fades
    &[data-scroll-none] {
      mask-image: none;
      -webkit-mask-image: none;
    }
  }

// ─────────────────────────────────────────────────────────────────────────────
// OVERFLOW: wrap
//
// Tabs wrap to the next line.
// ─────────────────────────────────────────────────────────────────────────────

  .vi-tabs--overflow-wrap .vi-tabs__tablist {
    flex-wrap: wrap;
    overflow: visible;
    height: auto;
  }

// ─────────────────────────────────────────────────────────────────────────────
// OVERFLOW: menu — "More" button + dropdown
// ─────────────────────────────────────────────────────────────────────────────

// More wrapper sits at end of tablist
  .vi-tabs__more-wrapper {
    position: relative;
    display: inline-flex;
    align-items: stretch;
    flex-shrink: 0;
    margin-left: auto;
    order: 9999; // ensure it sits after visually reordered tabs
  }

// More trigger button
  .vi-tabs__more-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--vi-tabs-gap-sm, 4px);
    padding: var(--vi-tabs-spacing-none-lg, 0 14px);
    min-height: 44px;
    border: none;
    background: transparent;
    cursor: pointer;
    font-family: inherit;
    font-size: #{func.to-rem(13px)};
    font-weight: 500;
    color: var(--vi-tabs-text-secondary, #{tokens.$text-secondary});
    border-radius: #{func.to-rem(6px)} #{func.to-rem(6px)} 0 0;
    transition: color 150ms ease, background-color 150ms ease;

    &:hover {
      color: var(--vi-tabs-text-primary, #{tokens.$text-primary});
      background: rgba(0, 0, 0, 0.04);
    }

    &--open {
      color: var(--vi-tabs-primary-color, #{tokens.$color-primary});
    }
  }

  .vi-tabs__more-chevron {
    flex-shrink: 0;
    transition: transform 200ms ease;

    .vi-tabs__more-btn--open & {
      transform: rotate(180deg);
    }
  }

// More dropdown menu
  .vi-tabs__more-menu {
    position: absolute;
    top: calc(100% + 4px);
    right: 0;
    z-index: 100;
    min-width: 180px;
    background: var(--vi-tabs-surface-primary, #{tokens.$layer-01});
    border: 1px solid var(--vi-tabs-border-color, #{tokens.$color-border});
    border-radius: #{func.to-rem(8px)};
    box-shadow: #{tokens.$shadow-md};
    padding: var(--vi-tabs-spacing-xs, 4px);
    animation: vi-menu-appear 150ms cubic-bezier(0.4, 0, 0.2, 1);
    transform-origin: top right;
  }

  @keyframes vi-menu-appear {
    from { opacity: 0; transform: scale(0.95) translateY(-4px); }
    to   { opacity: 1; transform: scale(1)    translateY(0); }
  }

// Individual menu item
  .vi-tabs__more-item {
    display: flex;
    align-items: center;
    width: 100%;
    padding: var(--vi-tabs-spacing-md-lg, 8px 12px);
    border: none;
    border-radius: #{func.to-rem(6px)};
    background: transparent;
    font-family: inherit;
    font-size: #{func.to-rem(13.5px)};
    font-weight: 500;
    color: var(--vi-tabs-text-secondary, #{tokens.$text-secondary});
    cursor: pointer;
    text-align: left;
    transition: background-color 100ms ease, color 100ms ease;

    &:hover:not(:disabled) {
      background: var(--vi-tabs-surface-secondary, #{tokens.$layer-02});
      color: var(--vi-tabs-text-primary, #{tokens.$text-primary});
    }

    &:disabled {
      color: var(--vi-tabs-text-disabled, #{tokens.$text-disabled});
      cursor: not-allowed;
    }

    &--active {
      color: var(--vi-tabs-primary-color, #{tokens.$color-primary});
      font-weight: 600;
      background: color-mix(in srgb, #{tokens.$color-primary} 6%, transparent);

      &:hover {
        background: color-mix(in srgb, #{tokens.$color-primary} 10%, transparent);
      }
    }
  }


}