#!/usr/bin/env bash
# check-process.sh
# Process compliance checks for PR branches.
# Validates: no main commits, no .DS_Store, scripts executable,
# spec artifacts exist, iteration counter incremented, commit tags,
# and file-scope allowlist enforcement.
set -euo pipefail

BASE_REF="${1:-origin/main}"

if ! git rev-parse --verify "$BASE_REF" >/dev/null 2>&1; then
  BASE_REF="HEAD~1"
fi

BRANCH="$(git rev-parse --abbrev-ref HEAD)"
# In GitHub Actions merge refs, HEAD is detached. Derive branch from GITHUB_HEAD_REF
# or from the spec directory that matches changed files.
if [[ "$BRANCH" == "HEAD" ]]; then
  if [[ -n "${GITHUB_HEAD_REF:-}" ]]; then
    BRANCH="$GITHUB_HEAD_REF"
  else
    # Fallback: find the spec directory from changed files
    for f in "${CHANGED_FILES[@]:-}"; do
      if [[ "$f" == specs/*/spec.md ]]; then
        BRANCH="${f#specs/}"
        BRANCH="${BRANCH%/spec.md}"
        break
      fi
    done
  fi
fi
if [[ "$BRANCH" == "main" ]]; then
  echo "[check-process] Failing: direct changes on 'main' are not allowed."
  exit 1
fi

CHANGED_FILES=()
while IFS= read -r line; do
  [[ -n "$line" ]] && CHANGED_FILES+=("$line")
done < <(git diff --name-only "$BASE_REF"...HEAD)

if [[ ${#CHANGED_FILES[@]} -eq 0 ]]; then
  echo "[check-process] No changed files relative to $BASE_REF."
  exit 0
fi

FAILURES=0

# --- Check 1: No .DS_Store ---
if command -v rg >/dev/null 2>&1; then
  HAS_DS_STORE="$(printf '%s\n' "${CHANGED_FILES[@]}" | rg -q '(^|/)\.DS_Store$' && echo 1 || echo 0)"
else
  HAS_DS_STORE="$(printf '%s\n' "${CHANGED_FILES[@]}" | grep -Eq '(^|/)\.DS_Store$' && echo 1 || echo 0)"
fi
if [[ "$HAS_DS_STORE" == "1" ]]; then
  echo "[check-process] FAIL: .DS_Store must not be committed."
  FAILURES=$((FAILURES + 1))
fi

# --- Check 2: Scripts executable ---
for file in "${CHANGED_FILES[@]}"; do
  if [[ "$file" == scripts/*.sh ]] && [[ -f "$file" ]] && [[ ! -x "$file" ]]; then
    echo "[check-process] FAIL: script is not executable: $file"
    FAILURES=$((FAILURES + 1))
  fi
done

# --- Check 3: Spec artifacts exist ---
SPEC_DIR="specs/${BRANCH}"
if [[ -d "$SPEC_DIR" ]]; then
  for artifact in spec.md plan.md tasks.md allowed-files.txt; do
    if [[ ! -f "$SPEC_DIR/$artifact" ]]; then
      echo "[check-process] FAIL: missing spec artifact: $SPEC_DIR/$artifact"
      FAILURES=$((FAILURES + 1))
    fi
  done
else
  echo "[check-process] FAIL: spec directory not found: $SPEC_DIR"
  FAILURES=$((FAILURES + 1))
fi

# --- Check 4: ITERATION incremented ---
if [[ -f ITERATION ]]; then
  BRANCH_ITER="$(tr -d '[:space:]' < ITERATION)"
  BASE_ITER="$(git show "$BASE_REF":ITERATION 2>/dev/null | tr -d '[:space:]' || echo "0")"
  if [[ "$BRANCH_ITER" -le "$BASE_ITER" ]] 2>/dev/null; then
    echo "[check-process] FAIL: ITERATION ($BRANCH_ITER) must be > base ($BASE_ITER)"
    FAILURES=$((FAILURES + 1))
  fi
fi

# --- Check 5: Commit messages contain [iter N] ---
# Skip merge commits (merge resolution, GitHub merge refs) — they don't carry iter tags.
COMMITS_WITHOUT_TAG=0
while IFS= read -r msg; do
  # Skip merge commits (start with "Merge " or "merge:")
  if echo "$msg" | grep -qEi '^(Merge |merge:)'; then
    continue
  fi
  if ! echo "$msg" | grep -qE '\[iter [0-9]+\]'; then
    echo "[check-process] FAIL: commit missing [iter N] tag: $msg"
    COMMITS_WITHOUT_TAG=$((COMMITS_WITHOUT_TAG + 1))
  fi
done < <(git log --format='%s' "$BASE_REF"...HEAD)
if [[ $COMMITS_WITHOUT_TAG -gt 0 ]]; then
  FAILURES=$((FAILURES + COMMITS_WITHOUT_TAG))
fi

# --- Check 6: File-scope allowlist ---
ALLOWLIST="$SPEC_DIR/allowed-files.txt"
if [[ -f "$ALLOWLIST" ]]; then
  ALLOWED_PATTERNS=()
  while IFS= read -r line; do
    # Skip comments and blank lines
    line="$(echo "$line" | sed 's/#.*//' | xargs)"
    [[ -z "$line" ]] && continue
    ALLOWED_PATTERNS+=("$line")
  done < "$ALLOWLIST"

  for file in "${CHANGED_FILES[@]}"; do
    MATCHED=false
    for pattern in "${ALLOWED_PATTERNS[@]}"; do
      # Use bash pattern matching (supports * and **)
      # Convert ** to match any path and * to match within directory
      local_pattern="${pattern}"
      # shellcheck disable=SC2254
      if [[ "$file" == $local_pattern ]]; then
        MATCHED=true
        break
      fi
      # Also try fnmatch-style: specs/foo/* should match specs/foo/bar.md
      if command -v python3 >/dev/null 2>&1; then
        if python3 -c "import fnmatch; exit(0 if fnmatch.fnmatch('$file', '$local_pattern') else 1)" 2>/dev/null; then
          MATCHED=true
          break
        fi
      fi
    done
    if [[ "$MATCHED" == "false" ]]; then
      echo "[check-process] FAIL: file not in allowlist: $file"
      FAILURES=$((FAILURES + 1))
    fi
  done
fi

# --- Result ---
if [[ $FAILURES -gt 0 ]]; then
  echo "[check-process] FAILED ($FAILURES issues)"
  exit 1
fi

echo "[check-process] PASS ($BASE_REF...HEAD)"