#!/usr/bin/env bash

# Bazelisk looks for this file, and runs it in place of the Bazel command if present.	
# See https://github.com/bazelbuild/bazelisk/blob/master/README.md#other-features	
# This gives us a place to create a custom environment for Bazel to run in.

set -eu

BOLD=$([ -t 0 ] && tput bold || echo "")
RED=$([ -t 0 ] && tput setaf 1 || echo "")
GREEN=$([ -t 0 ] && tput setaf 2 || echo "")
YELLOW=$([ -t 0 ] && tput setaf 3 || echo "")
CL=$([ -t 0 ] && tput sgr0 || echo "") # reset

readonly COMPLETION_SNIPPET_DELIM="bazel-completion"
readonly COMPLETION_SNIPPET_BEGIN_DELIM="# BEGIN-${COMPLETION_SNIPPET_DELIM}"
readonly COMPLETION_SNIPPET_END_DELIM="# END-${COMPLETION_SNIPPET_DELIM}"

ARGS=( "$@" )
TARGETS_AND_FLAGS=( "${ARGS[@]:1}" )
TARGETS=( "${TARGETS_AND_FLAGS[@]%%-*}" )

print_help() {
    VERB=${1}
    DESC=${2}

    LENGTH=${#VERB}
    while [[ ${LENGTH} -lt 20 ]]; do
        VERB="${VERB} "
        LENGTH=${#VERB}
    done

    echo "  ${VERB}${DESC}"
}

#######################################
# Modify an rcfile with a snippet without duplication.
#
# Globals:
#   COMPLETION_SNIPPET_BEGIN_DELIM
#   COMPLETION_SNIPPET_END_DELIM
# Arguments:
#   RCFILE - the rcfile to modify
#   SNIPPET_TMP - a file containing the snippet to append to RCFILE
#######################################
append_to_rcfile() {
    RCFILE="${1}"
    SNIPPET_TMP="${2}"

    RCFILE_TMP=$(mktemp)
    PATTERN_TMP=$(mktemp)

    echo "/^${COMPLETION_SNIPPET_BEGIN_DELIM}/,/^${COMPLETION_SNIPPET_END_DELIM}/{next}1" > "${PATTERN_TMP}"
    awk -f "${PATTERN_TMP}" "$RCFILE" > "${RCFILE_TMP}"
    cat "${SNIPPET_TMP}" >> "${RCFILE_TMP}"
    cp "${RCFILE_TMP}" "${RCFILE}"
    rm "${PATTERN_TMP}" "${SNIPPET_TMP}" "${RCFILE_TMP}"

    echo -e "${YELLOW}Completion snippet added to ${RCFILE}${CL}"
}

#######################################
# Configure autocompletion for bazel.
# Optimistically tries to configure for both zsh and bash.
#
# Globals:
#   HOME
#   COMPLETION_SNIPPET_BEGIN_DELIM
#   COMPLETION_SNIPPET_END_DELIM
# Arguments:
#   None
#######################################
configure_bazel_autocompletion() {
    readonly ZSHRC="${HOME}/.zshrc"
    readonly BASH_PROFILE="${HOME}/.bash_profile"
    readonly WORKSPACE_DIR=$(bazel info workspace --ui_event_filters=-INFO)

    DID_CONFIGURE="none"

    ##
    ## Zsh
    ##
    if [[ -f "${ZSHRC}" ]]; then
        readonly ZSH_COMPLETION_SCRIPT="${WORKSPACE_DIR}/bazel/completion/zsh/_bazel"
        readonly ZSH_SNIPPET_TMP=$(mktemp)

        mkdir -p "${HOME}/.zsh/completion/"
        cp "${ZSH_COMPLETION_SCRIPT}" "${HOME}/.zsh/completion/"
        cat << EOF >> "${ZSH_SNIPPET_TMP}"
${COMPLETION_SNIPPET_BEGIN_DELIM}
autoload -U +X compinit && compinit
zstyle ':completion:*' use-cache on
zstyle ':completion:*' cache-path ~/.zsh/cache
fpath[1,0]=~/.zsh/completion/
${COMPLETION_SNIPPET_END_DELIM}
EOF
        append_to_rcfile "${ZSHRC}" "${ZSH_SNIPPET_TMP}"
        DID_CONFIGURE="zsh"
    fi 

    ##
    ## Bash
    ##
    if [[ -f "${BASH_PROFILE}" ]]; then
        readonly BASH_COMPLETION_SCRIPT="${WORKSPACE_DIR}/bazel/completion/bash/bazel.bash"
        readonly BASH_SNIPPET_TMP=$(mktemp)

        cat << EOF >> "${BASH_SNIPPET_TMP}"
${COMPLETION_SNIPPET_BEGIN_DELIM}
if [ -f "${BASH_COMPLETION_SCRIPT}" ]; then
    source "${BASH_COMPLETION_SCRIPT}"
fi
${COMPLETION_SNIPPET_END_DELIM}
EOF
        append_to_rcfile "${BASH_PROFILE}" "${BASH_SNIPPET_TMP}"
        DID_CONFIGURE="bash"
    fi

    if [[ "${DID_CONFIGURE}" == "none" ]]; then
        echo -e "${RED}Completion setup was expecting to find ${BASH_PROFILE} or ${ZSHRC}${CL}."
        echo -e "${YELLOW}Please contact the #bazel slack channel for help.${CL}"
        exit 1
    fi

    echo -e "${GREEN}Bazel completion should now be available (in a new terminal) 🎉${CL}"
}

case "${ARGS[0]}" in
    "completion")
        if [ ! -x ${TARGETS+x} ]; then
            echo -e "${RED}ERROR${CL}: 'bazel completion' does not take any arguments."
            exit 1
        fi

        configure_bazel_autocompletion
    ;;
    "outputs")
        if [ -x ${TARGETS+x} ]; then
            echo -e "${RED}ERROR${CL} Requested an empty set of targets\nUsage: 'bazel outputs <targets>'"
            exit 1
        fi

        echo -e "Querying for outputs for ${TARGETS[*]}\n"

        for T in "${TARGETS[@]}"; do
            OUTS=$(${BAZEL_REAL} aquery "${T}" --include_commandline=false --output jsonproto 2> /dev/null |\
                jq --raw-output '((.actions[]?.outputIds)[] as $ids | (.artifacts[] | select(.id | IN( $ids )))) as $art | $art.execPath')

            echo "${BOLD}${T}${CL}:"
            if [ -x ${OUTS+x} ]; then
                echo -e "\t${YELLOW}No outputs${CL}"
            else
                printf "\t${GREEN}%s${CL}\n" "${OUTS[@]}"
            fi
        done
    ;;
    "help" | "--help")
        ${BAZEL_REAL} "$@"

        if [[ "${#ARGS[@]}" -eq 1 ]]; then
            echo -e "\nCustom commands:"
            print_help "outputs" "Prints the output paths to any artifacts that are created when requesting a build"
            print_help "completion" "Configures bazel CLI autocompletion for ~/.zshrc and/or ~/.bash_profile."
        fi
    ;;
    *)
        exec -a bazel "${BAZEL_REAL}" "$@"
esac