#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
cd "$ROOT_DIR"

HAS_RG=0
if command -v rg >/dev/null 2>&1; then
  HAS_RG=1
else
  echo "warn: ripgrep (rg) not found; using find/grep fallback (slower)."
fi

NON_TEST_GLOBS=(
  -g '*.rs'
  -g '!**/tests/**'
  -g '!**/tests.rs'
  -g '!**/test_*.rs'
  -g '!**/*_test.rs'
)

FAILED=0

list_non_test_rust_files() {
  if [[ "$HAS_RG" -eq 1 ]]; then
    rg --files src "${NON_TEST_GLOBS[@]}"
  else
    find src -type f -name '*.rs' \
      ! -path '*/tests/*' \
      ! -name 'tests.rs' \
      ! -name 'test_*.rs' \
      ! -name '*_test.rs' \
      | sort
  fi
}

count_matching_files() {
  local needle="$1"
  local file_path
  local count=0

  while IFS= read -r file_path; do
    if grep -Fq -- "$needle" "$file_path"; then
      count=$((count + 1))
    fi
  done < <(list_non_test_rust_files)

  echo "$count"
}

find_non_test_layer_matches() {
  local layer_dir="$1"
  local regex="$2"
  local file_path
  local match_tmp

  match_tmp="$(mktemp)"
  while IFS= read -r file_path; do
    [[ "$file_path" == "${layer_dir}/"* ]] || continue
    grep -n -E -- "$regex" "$file_path" >> "$match_tmp" || true
  done < <(list_non_test_rust_files)

  if [[ -s "$match_tmp" ]]; then
    cat "$match_tmp"
  fi
  rm -f "$match_tmp"
}

check_forbidden_crates_in_layer() {
  local layer_dir="$1"
  shift
  local crates=("$@")

  if [[ ! -d "$layer_dir" ]]; then
    echo "skip: ${layer_dir} not present"
    return 0
  fi

  local crate_name
  for crate_name in "${crates[@]}"; do
    local regex="\\b${crate_name}::"
    local matches
    if [[ "$HAS_RG" -eq 1 ]]; then
      matches="$(rg -n "${NON_TEST_GLOBS[@]}" "$regex" "$layer_dir" || true)"
    else
      matches="$(find_non_test_layer_matches "$layer_dir" "$regex")"
    fi
    if [[ -n "$matches" ]]; then
      echo "error: forbidden '${crate_name}' usage detected in ${layer_dir}"
      printf '%s\n' "$matches"
      FAILED=1
    else
      echo "ok: ${layer_dir} has no '${crate_name}' usage"
    fi
  done
}

check_forbidden_pattern_in_layer() {
  local layer_dir="$1"
  local description="$2"
  local regex="$3"

  if [[ ! -d "$layer_dir" ]]; then
    echo "skip: ${layer_dir} not present"
    return 0
  fi

  local matches
  if [[ "$HAS_RG" -eq 1 ]]; then
    matches="$(rg -n "${NON_TEST_GLOBS[@]}" "$regex" "$layer_dir" || true)"
  else
    matches="$(find_non_test_layer_matches "$layer_dir" "$regex")"
  fi
  if [[ -n "$matches" ]]; then
    echo "error: forbidden ${description} detected in ${layer_dir}"
    printf '%s\n' "$matches"
    FAILED=1
  else
    echo "ok: ${layer_dir} has no ${description}"
  fi
}

print_top_module_edges() {
  local edge_tmp
  edge_tmp="$(mktemp)"

  while IFS= read -r file_path; do
    local source_module
    source_module="${file_path#src/}"
    source_module="${source_module%%/*}"

    while IFS= read -r ref; do
      local target_module
      target_module="${ref#crate::}"
      [[ "$target_module" == "$source_module" ]] && continue
      printf '%s -> %s\n' "$source_module" "$target_module" >> "$edge_tmp"
    done < <(find_use_refs "$file_path")
  done < <(list_non_test_rust_files)

  if [[ ! -s "$edge_tmp" ]]; then
    echo "  (none)"
    rm -f "$edge_tmp"
    return 0
  fi

  awk '{count[$0]++} END {for (k in count) printf "%d\t%s\n", count[k], k}' "$edge_tmp" \
    | sort -nr -k1,1 -k2,2 \
    | head -n 10 \
    | awk -F'\t' '{printf "  %s (%s)\n", $2, $1}'

  rm -f "$edge_tmp"
}

find_use_refs() {
  local file_path="$1"
  if [[ "$HAS_RG" -eq 1 ]]; then
    rg --no-filename '^use ' "$file_path" \
      | rg -o 'crate::[A-Za-z_][A-Za-z0-9_]*' \
      | sort -u \
      || true
  else
    grep -E '^use ' "$file_path" \
      | grep -oE 'crate::[A-Za-z_][A-Za-z0-9_]*' \
      | sort -u \
      || true
  fi
}

echo "Architecture boundary checks"
check_forbidden_crates_in_layer "src/domain" "clap" "reqwest" "tokio" "ratatui" "crossterm"
check_forbidden_crates_in_layer "src/application" "clap"
check_forbidden_pattern_in_layer "src/application" "'TesterArgs' references" "\\bTesterArgs\\b"
check_forbidden_pattern_in_layer "src/application" "'crate::args' imports" "crate::args::"
check_forbidden_pattern_in_layer "src/application" "'crate::app' imports" "crate::app::"
check_forbidden_pattern_in_layer "src/application" "'crate::distributed' imports" "crate::distributed::"
check_forbidden_pattern_in_layer "src/distributed" "'crate::app' imports" "crate::app::"
check_forbidden_pattern_in_layer "src/distributed" "'crate::application' imports" "crate::application::"
check_forbidden_pattern_in_layer "src/entry" "'crate::app' imports" "crate::app::"
check_forbidden_pattern_in_layer "src/entry" "'crate::distributed' imports" "crate::distributed::"
check_forbidden_pattern_in_layer "src/entry" "'crate::service' imports" "crate::service::"

echo
echo "Coupling baseline metrics"
echo "  non_test_rust_files: $(list_non_test_rust_files | wc -l | tr -d '[:space:]')"
echo "  files_referencing_crate_args: $(count_matching_files 'crate::args')"
echo "  files_referencing_tester_args: $(count_matching_files 'TesterArgs')"
echo "  top_cross_module_edges:"
print_top_module_edges

if [[ "$FAILED" -ne 0 ]]; then
  exit 1
fi