#!/usr/bin/env bash
# check-browser-parity.sh — Verify Chrome/Firefox extension parity for all providers.
#
# Compares all source files between Firefox (-exporter-extension) and Chrome
# (-exporter-chrome) variants. The only allowed difference is the
# browser_specific_settings.gecko block in manifest.json.
#
# Usage: scripts/check-browser-parity.sh

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
EXT_ROOT="$REPO_ROOT/browser-extensions/history-extensions"

PROVIDERS=(gemini copilot deepseek grok perplexity poe)

# Files that must be byte-identical between variants.
PARITY_FILES=(
  src/content/content.js
  src/lib/export.js
  src/lib/popup-core.js
  src/lib/popup-utils.js
  src/popup/popup.js
  src/popup/popup.html
  src/popup/popup.css
  src/popup/permissions.html
)

log() {
  printf '[parity] %s\n' "$*"
}

err() {
  printf '[parity] FAIL: %s\n' "$*" >&2
}

failures=0
checks=0

for provider in "${PROVIDERS[@]}"; do
  firefox_dir="$EXT_ROOT/${provider}-exporter-extension"
  chrome_dir="$EXT_ROOT/${provider}-exporter-chrome"

  if [[ ! -d "$firefox_dir" ]]; then
    err "$provider — Firefox directory missing: $firefox_dir"
    failures=$((failures + 1))
    continue
  fi

  if [[ ! -d "$chrome_dir" ]]; then
    err "$provider — Chrome directory missing: $chrome_dir"
    failures=$((failures + 1))
    continue
  fi

  for file in "${PARITY_FILES[@]}"; do
    checks=$((checks + 1))
    ff_path="$firefox_dir/$file"
    cr_path="$chrome_dir/$file"

    if [[ ! -f "$ff_path" ]]; then
      err "$provider — Firefox missing: $file"
      failures=$((failures + 1))
      continue
    fi

    if [[ ! -f "$cr_path" ]]; then
      err "$provider — Chrome missing: $file"
      failures=$((failures + 1))
      continue
    fi

    if ! diff -q "$ff_path" "$cr_path" >/dev/null 2>&1; then
      err "$provider — $file differs between Firefox and Chrome"
      failures=$((failures + 1))
    fi
  done

  # Validate manifest.json: only browser_specific_settings.gecko should differ.
  checks=$((checks + 1))
  ff_manifest="$firefox_dir/manifest.json"
  cr_manifest="$chrome_dir/manifest.json"

  if [[ ! -f "$ff_manifest" || ! -f "$cr_manifest" ]]; then
    err "$provider — manifest.json missing from one or both variants"
    failures=$((failures + 1))
    continue
  fi

  # Strip browser_specific_settings block from Firefox manifest and normalize
  # trailing commas so the remaining JSON structure matches Chrome.
  ff_stripped=$(sed '/"browser_specific_settings"/,/^  }/d' "$ff_manifest" | sed '/^$/d' | sed 's/,$//')
  cr_stripped=$(sed '/^$/d' "$cr_manifest" | sed 's/,$//')

  if ! diff -q <(echo "$ff_stripped") <(echo "$cr_stripped") >/dev/null 2>&1; then
    err "$provider — manifest.json has unexpected differences beyond browser_specific_settings"
    failures=$((failures + 1))
  fi
done

echo ""
passed=$((checks - failures))
log "Results: ${passed} passed, ${failures} failed (${checks} checks across ${#PROVIDERS[@]} providers)"

if [[ "$failures" -gt 0 ]]; then
  err "Browser parity check failed."
  exit 1
fi

log "All browser parity checks passed."
exit 0