#!/usr/bin/env bash
# purpose: enforce the theme contract — every var(--token) a consumer's CSS uses must be defined in the synced theme (or the consumer's own CSS), and a theme's colors must live only in :root | usage: bash scripts/theme-contract.sh --theme <theme.css> | bash scripts/theme-contract.sh --consumer <src-dir> <theme.css> | inputs: css files | outputs: missing-token list + exit 0/1
set -euo pipefail

MODE="${1:-}"
case "$MODE" in
  --theme)
    THEME_CSS="${2:?usage: theme-contract.sh --theme <theme.css>}"
    ;;
  --consumer)
    SRC_DIR="${2:?usage: theme-contract.sh --consumer <src-dir> <theme.css>}"
    THEME_CSS="${3:?usage: theme-contract.sh --consumer <src-dir> <theme.css>}"
    ;;
  *)
    echo "usage: theme-contract.sh --theme <theme.css> | --consumer <src-dir> <theme.css>" >&2
    exit 2
    ;;
esac

[ -f "$THEME_CSS" ] || { echo "theme-contract: theme.css not found: $THEME_CSS" >&2; exit 1; }

# Tokens DEFINED in the theme: lines like "  --token-name: value;" (any scope).
# Note: pipelines end in `|| true` — grep exits 1 on no match and set -e
# would otherwise abort the script on the first token-less file.
theme_tokens() {
  sed -E 's|/\*.*\*/||g' "$THEME_CSS" \
    | grep -oE '[[:space:]]*--[A-Za-z0-9_-]+[[:space:]]*:' \
    | sed -E 's/^[[:space:]]*(--[A-Za-z0-9_-]+)[[:space:]]*:$/\1/' \
    | sort -u || true
}

extract_defined_tokens() { # $1 = css file -> defined --token names
  sed -E 's|/\*.*\*/||g' "$1" \
    | grep -oE '[[:space:]]*--[A-Za-z0-9_-]+[[:space:]]*:' \
    | sed -E 's/^[[:space:]]*(--[A-Za-z0-9_-]+)[[:space:]]*:$/\1/' \
    || true
}

extract_used_vars() { # $1 = css file -> used var(--token) names
  sed -E 's|/\*.*\*/||g' "$1" \
    | grep -oE 'var\(--[A-Za-z0-9_-]+' \
    | sed -E 's/^var\((--[A-Za-z0-9_-]+)$/\1/' \
    || true
}

if [ "$MODE" = "--theme" ]; then
  # Theme-side rule: no hardcoded colors outside the :root block.
  OUTSIDE_COLORS=$(awk '/:root/{inroot=1} /^\}/{inroot=0} !inroot' "$THEME_CSS" \
    | grep -cE '#[0-9a-fA-F]{3,8}|hsl\(|rgb\(' || true)
  if [ "$OUTSIDE_COLORS" -ne "0" ]; then
    echo "theme-contract FAIL: $OUTSIDE_COLORS hardcoded color(s) outside :root in $THEME_CSS (tokens only, then var())" >&2
    exit 1
  fi
  echo "theme-contract: theme OK — token count: $(theme_tokens | wc -l | tr -d ' '), all colors inside :root"
  exit 0
fi

# Consumer-side rule: every var(--x) in consumer CSS resolves to a token
# defined in the theme OR in the consumer's own CSS.
[ -d "$SRC_DIR" ] || { echo "theme-contract: src dir not found: $SRC_DIR" >&2; exit 1; }

THEME_TOKENS=$(theme_tokens)
DEFINED="$THEME_TOKENS"
USED_FILE=$(mktemp)
trap 'rm -f "$USED_FILE"' EXIT

# Gather consumer-defined tokens + used vars from every css file under SRC_DIR,
# skipping node_modules and the synced theme copy itself (it IS the theme).
while IFS= read -r css; do
  case "$css" in
    */node_modules/*|*/src/styles/theme/*) continue ;;
  esac
  DEFINED="$DEFINED
$(extract_defined_tokens "$css")"
  extract_used_vars "$css" >> "$USED_FILE"
done < <(find "$SRC_DIR" -name '*.css' -type f)

sort -u "$USED_FILE" > "$USED_FILE.sorted"
mv "$USED_FILE.sorted" "$USED_FILE"

MISSING=0
while IFS= read -r tok; do
  [ -z "$tok" ] && continue
  if ! grep -qxF -- "$tok" <<< "$DEFINED" 2>/dev/null; then
    echo "theme-contract: undefined token used: $tok" >&2
    MISSING=1
  fi
done < "$USED_FILE"

if [ "$MISSING" -ne "0" ]; then
  echo "theme-contract FAIL: consumer CSS references tokens not defined in theme.css or its own CSS" >&2
  exit 1
fi
echo "theme-contract: consumer OK — $(wc -l < "$USED_FILE" | tr -d ' ') unique var() tokens all resolve"
exit 0