#!/usr/bin/env bash

set -u -o pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
REPORT_DIR="$ROOT_DIR/reports"
ERROR_REPORT="$REPORT_DIR/errors.md"
GENERATED_REPORT="$REPORT_DIR/generated-files.md"
STATUS_FILE="$REPORT_DIR/customer-code-status.txt"
TMP_DIR=""

FILES_CHECKED=0
WARNINGS=0
ERRORS=0

DETAILS=()
GENERATED_FILES=()

EXCLUDES=(
  ".git"
  ".forgejo"
  "node_modules"
  "vendor"
  "Library"
  "Temp"
  "Logs"
  "obj"
  "bin"
)

cleanup() {
  if [[ -n "$TMP_DIR" && -d "$TMP_DIR" ]]; then
    rm -rf "$TMP_DIR"
  fi
}

trap cleanup EXIT

record_generated_file() {
  local file="$1"
  local rel="${file#"$ROOT_DIR"/}"
  local existing

  for existing in "${GENERATED_FILES[@]}"; do
    if [[ "$existing" == "$rel" ]]; then
      return
    fi
  done

  GENERATED_FILES+=("$rel")
}

escape_md() {
  printf '%s' "$1" | sed 's/|/\\|/g'
}

have_tool() {
  command -v "$1" >/dev/null 2>&1
}

ensure_report_dir() {
  mkdir -p "$REPORT_DIR" || {
    printf 'Failed to create report directory: %s\n' "$REPORT_DIR" >&2
    return 1
  }
}

add_warning() {
  local message="$1"
  WARNINGS=$((WARNINGS + 1))
  DETAILS+=("- Warning: $(escape_md "$message")")
}

add_error() {
  local message="$1"
  ERRORS=$((ERRORS + 1))
  DETAILS+=("- Error: $(escape_md "$message")")
}

add_ok() {
  local message="$1"
  DETAILS+=("- OK: $(escape_md "$message")")
}

relative_path() {
  local path="$1"
  path="${path#"$ROOT_DIR"/}"
  printf '%s' "$path"
}

join_by() {
  local delimiter="$1"
  shift || true
  local first=1
  local item

  for item in "$@"; do
    [[ -z "$item" ]] && continue

    if [[ $first -eq 1 ]]; then
      printf '%s' "$item"
      first=0
    else
      printf '%s%s' "$delimiter" "$item"
    fi
  done
}

collect_files() {
  local find_args=("$ROOT_DIR")
  local exclude

  if ((${#EXCLUDES[@]} > 0)); then
    find_args+=("(")
    for exclude in "${EXCLUDES[@]}"; do
      find_args+=(-name "$exclude" -o)
    done
    unset 'find_args[${#find_args[@]}-1]'
    find_args+=(")" -prune -o)
  fi

  find_args+=(-type f -print0)
  find "${find_args[@]}"
}

run_check() {
  local label="$1"
  local file="$2"
  shift 2

  local stdout_file="$TMP_DIR/stdout.log"
  local stderr_file="$TMP_DIR/stderr.log"
  local stdout=""
  local stderr=""
  local combined=""

  FILES_CHECKED=$((FILES_CHECKED + 1))

  : >"$stdout_file"
  : >"$stderr_file"

  if "$@" >"$stdout_file" 2>"$stderr_file"; then
    add_ok "$label passed: $(relative_path "$file")"
  else
    stdout="$(tr '\n' ' ' <"$stdout_file" | sed 's/[[:space:]]\+/ /g; s/^ //; s/ $//')"
    stderr="$(tr '\n' ' ' <"$stderr_file" | sed 's/[[:space:]]\+/ /g; s/^ //; s/ $//')"
    combined="$(join_by ' | ' "${stdout:-}" "${stderr:-}")"
    add_error "$label failed: $(relative_path "$file")${combined:+ | $combined}"
  fi
}

run_repo_build_checks() {
  local sln_files=()
  local csproj_files=()
  local cmake_file="$ROOT_DIR/CMakeLists.txt"
  local tmp_cmake_dir=""

  while IFS= read -r -d '' file; do
    sln_files+=("$file")
  done < <(find "$ROOT_DIR" -path "$ROOT_DIR/.git" -prune -o -path "$ROOT_DIR/.forgejo" -prune -o -name '*.sln' -type f -print0)

  while IFS= read -r -d '' file; do
    csproj_files+=("$file")
  done < <(find "$ROOT_DIR" -path "$ROOT_DIR/.git" -prune -o -path "$ROOT_DIR/.forgejo" -prune -o -name '*.csproj' -type f -print0)

  if ((${#sln_files[@]} > 0 || ${#csproj_files[@]} > 0)); then
    if have_tool dotnet; then
      if ((${#sln_files[@]} > 0)); then
        local file
        for file in "${sln_files[@]}"; do
          run_check "dotnet build" "$file" dotnet build "$file" --nologo --verbosity minimal
        done
      else
        local file
        for file in "${csproj_files[@]}"; do
          run_check "dotnet build" "$file" dotnet build "$file" --nologo --verbosity minimal
        done
      fi
    else
      add_warning "dotnet not installed; skipping C# project validation."
    fi
  fi

  if [[ -f "$cmake_file" ]]; then
    if have_tool cmake; then
      FILES_CHECKED=$((FILES_CHECKED + 1))
      tmp_cmake_dir="$(mktemp -d)"
      if cmake -S "$ROOT_DIR" -B "$tmp_cmake_dir" >"$TMP_DIR/stdout.log" 2>"$TMP_DIR/stderr.log"; then
        add_ok "cmake configure passed: CMakeLists.txt"
      else
        local stdout stderr combined
        stdout="$(tr '\n' ' ' <"$TMP_DIR/stdout.log" | sed 's/[[:space:]]\+/ /g; s/^ //; s/ $//')"
        stderr="$(tr '\n' ' ' <"$TMP_DIR/stderr.log" | sed 's/[[:space:]]\+/ /g; s/^ //; s/ $//')"
        combined="$(join_by ' | ' "${stdout:-}" "${stderr:-}")"
        add_error "cmake configure failed: CMakeLists.txt${combined:+ | $combined}"
      fi
      rm -rf "$tmp_cmake_dir"
    else
      add_warning "cmake not installed; skipping C/C++ validation."
    fi
  fi
}

validate_file() {
  local file="$1"
  local base

  base="$(basename "$file")"

  case "$file" in
    *.php)
      if have_tool php; then
        run_check "php -l" "$file" php -l "$file"
      else
        add_warning "php not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.py)
      if have_tool python3; then
        run_check "python3 -m py_compile" "$file" python3 -m py_compile "$file"
      else
        add_warning "python3 not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.rb)
      if have_tool ruby; then
        run_check "ruby -c" "$file" ruby -c "$file"
      else
        add_warning "ruby not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.pl|*.pm)
      if have_tool perl; then
        run_check "perl -c" "$file" perl -c "$file"
      else
        add_warning "perl not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.sh|*.bash)
      if have_tool bash; then
        run_check "bash -n" "$file" bash -n "$file"
      else
        add_warning "bash not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.js|*.mjs|*.cjs)
      if have_tool node; then
        run_check "node --check" "$file" node --check "$file"
      else
        add_warning "node not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.json)
      if have_tool jq; then
        run_check "jq validation" "$file" jq empty "$file"
      else
        add_warning "jq not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.yml|*.yaml)
      if have_tool yamllint; then
        run_check "yamllint" "$file" yamllint -f parsable "$file"
      else
        add_warning "yamllint not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *.html|*.htm)
      if have_tool tidy; then
        run_check "tidy validation" "$file" tidy -qe "$file"
      else
        add_warning "tidy not installed; skipping $(relative_path "$file")"
      fi
      ;;
    *)
      if [[ "$base" == "Dockerfile" ]]; then
        FILES_CHECKED=$((FILES_CHECKED + 1))
        add_ok "Detected Dockerfile: $(relative_path "$file")"
      fi
      ;;
  esac
}

write_generated_files_report() {
  {
    printf '# Generated Files\n\n'
    if ((${#GENERATED_FILES[@]} == 0)); then
      printf 'No report files were generated.\n'
    else
      local file
      for file in "${GENERATED_FILES[@]}"; do
        printf -- '- %s\n' "$file"
      done
    fi
  } >"$GENERATED_REPORT" || return 1

  record_generated_file "$GENERATED_REPORT"
}

write_status_file() {
  local status_line="NO CUSTOMER CODE ERRORS FOUND"
  if ((ERRORS > 0)); then
    status_line="CUSTOMER CODE ERRORS FOUND"
  fi

  printf '%s\n' "$status_line" >"$STATUS_FILE" || return 1
  record_generated_file "$STATUS_FILE"
}

write_error_report() {
  local status_line="NO CUSTOMER CODE ERRORS FOUND"
  if ((ERRORS > 0)); then
    status_line="CUSTOMER CODE ERRORS FOUND"
  fi

  {
    printf '# Validation Summary\n\n'
    printf '%s\n\n' "$status_line"
    printf -- '- Files Checked: %s\n' "$FILES_CHECKED"
    printf -- '- Warnings: %s\n' "$WARNINGS"
    printf -- '- Errors: %s\n\n' "$ERRORS"
    printf '## Detailed Results\n\n'
    if ((${#DETAILS[@]} == 0)); then
      printf 'No validation steps were run.\n'
    else
      printf '%s\n' "${DETAILS[@]}"
    fi
  } >"$ERROR_REPORT" || return 1

  record_generated_file "$ERROR_REPORT"
}

print_terminal_summary() {
  local status_line="NO CUSTOMER CODE ERRORS FOUND"
  if ((ERRORS > 0)); then
    status_line="CUSTOMER CODE ERRORS FOUND"
  fi

  printf '===== VALIDATION SUMMARY =====\n'
  printf '%s\n' "$status_line"
  printf 'Files checked: %s\n' "$FILES_CHECKED"
  printf 'Warnings: %s\n' "$WARNINGS"
  printf 'Errors: %s\n' "$ERRORS"
  printf 'Reports written:\n'

  local file
  for file in "${GENERATED_FILES[@]}"; do
    printf -- '- %s\n' "$file"
  done
}

main() {
  ensure_report_dir || return 1
  TMP_DIR="$(mktemp -d)" || {
    printf 'Failed to create temporary directory.\n' >&2
    return 1
  }

  while IFS= read -r -d '' file; do
    validate_file "$file"
  done < <(collect_files)

  run_repo_build_checks

  write_status_file || return 1
  write_error_report || return 1
  write_generated_files_report || return 1
  print_terminal_summary

  return 0
}

main "$@"