#!/bin/bash
# Copyright 2020 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

#### CATEGORY=Source tree
### print lines in the Fuchsia sources matching the given pattern

## usage: fx grep [options] <pattern> [-- type_filter...]
##
## Convenience wrapper around 'jiri grep' to search the Fuchsia source tree and
## print lines matching the given pattern.
##
## Narrow your search to specific file types:
##   c, cpp: C/C++ source and header files
##   rs, rust: Rust source files
##   py, python: Python source files
##   go: Go source files
##   dart: Dart source files
##   fidl: FIDL source files
##   service, config: Services configuration files
##   cm, manifest: Component manifest files
##   gn, build: GN build files
##   md, doc: Documentation source files
##
## The following example searches both C++ and Python files for 'tcgetattr':
##   fx grep tcgetattr -- cpp py

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/../lib/vars.sh || exit $?

set -e

# Map supported options to list of file types
SELECTED_FILE_TYPES=()
get_type_list() {
  case $1 in
      'c'|'cpp') SELECTED_FILE_TYPES+=('*.c' '*.cc' '*.cpp' '*.h' '*.hpp');;
      'rs'|'rust') SELECTED_FILE_TYPES+=('*.rs');;
      'py'|'python') SELECTED_FILE_TYPES+=('*.py');;
      'go') SELECTED_FILE_TYPES+=('*.go');;
      'dart') SELECTED_FILE_TYPES+=('*.dart');;
      'fidl') SELECTED_FILE_TYPES+=('*.fidl');;
      'service'|'config') SELECTED_FILE_TYPES+=('*.config');;
      'cm'|'manifest') SELECTED_FILE_TYPES+=('*.cml');;
      'gn'|'build') SELECTED_FILE_TYPES+=('*.gn' '*.gni');;
      'md'|'doc') SELECTED_FILE_TYPES+=('*.md');;
      *) fx-error "Unsupported file type: $1" && fx-command-help && exit 1;;
  esac
}

# Separate grep arguments from file filters
COMMAND_OPTS=()
while [[ $# -gt 0 ]]; do
  case "$1" in
      --help|-h)
        fx-command-help
        exit 0
        ;;
      --)
        shift
        break
        ;;
      -*)
        COMMAND_OPTS+=( $1 )
        shift
        ;;
      *)
        COMMAND_QUERY="$1"
        shift
        ;;
  esac
done

# Check arguments for a valid query pattern
if [[ -z "$COMMAND_QUERY" ]]; then
  # No pattern argument available
  fx-error "grep requires a query pattern"
  fx-command-help
  exit 1
fi

# Check filter arguments
for i in "$@"; do
  get_type_list "$i"
done

# Build pathspec from chosen file types
FILTER_ARGS=()
if [[ ${#SELECTED_FILE_TYPES[@]} -ne 0 ]]; then
    # Search selected file types
    FILTER_ARGS+=(--)
    for i in "${SELECTED_FILE_TYPES[@]}"; do
      FILTER_ARGS+=( ":/**/${i}" )
    done
fi

fx-command-run jiri grep "${COMMAND_OPTS[@]}" "${COMMAND_QUERY}" "${FILTER_ARGS[@]}"