.functions.macos

#!/bin/sh

# all of these functions are declared in subshells
# the reason is that ksh does not support 'local' (only typeset with function keyword) whereas dash does not support "typeset"

# unlike  'brew home' and 'brew homepage', print homepage of homebrew formula(e) without opening it
bhome() (
    # return Homebrew's homepage by default, which mimics 'brew home' behavior in the analogous situation
    if [ $# -eq 0 ]; then 
        bold="\033[1m"
        # cannot use 'end' as variable name because zsh's 'zargs' module uses it internally (zargs allows shell functions to be executed from std input, unlike xargs)
        # hence we use the variable name 'ending' instead so that we won't have a crah when our functions are provded as argument to the zargs fct in zsh 
        ending="\033[0m"
        homebrew_page="http://brew.sh"
        if [ -t 1 ]; then # use color when standard output is a terminal
            python -c "print(\"$bold\"+\"homebrew: \"+\"$ending\"+\"$homebrew_page\")"
        else
            printf "homebrew: %s\n" "$homebrew_page"
        fi
        return 0
    fi
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "homepage" $formulae
)

# print description and homepage of homebrew formula(e), in that order
bdeschome() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "desc homepage" $formulae
)

# print full name of homebrew formula(e)
bfname() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "full_name" $formulae
)

# print full name of homebrew formula(e)
bdep() {
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "dependencies" $formulae 
}
 
# print description, homepage and full name of homebrew formula(e), in that order  
bfull() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "desc homepage full_name" $formulae
)

# same as 'bfull', only the homepage comes before the description
bfullhome() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "homepage desc full_name" $formulae
)

# print description, homepage, dependencies and full name of homebrew formula(e), in that order
bfulldep() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "desc homepage dependencies full_name" $formulae
)

# same as 'bfulldep', only the homepage comes before the description
bfulldephome() (
    formulae="$*"
    # shellcheck disable=SC2086
    _brew_json "homepage desc dependencies full_name" $formulae
)

# make formula name bold, then gray out every second field
_build_line() (
    fields="$1"
    bold="\033[1m"
    ending="\033[0m"
    gray="\033[1;30m"
    line="print('$bold'+formula['name']"
    column_index=2
    command -v setopt >/dev/null 2>&1 && setopt shwordsplit
    for field in $fields; do
        line=$line"+': '+'$ending'"
        # make every odd column gray (except for first column, which gives 'name' by default and is bold)
        [ $((column_index%2)) -ne 0 ] && line=$line"+'$gray'"
        # ugly inline if else to turn python 2 unicode strings within list into regular string
        row="(formula['$field'] if not isinstance(formula['$field'],list) else str([ str(f) for f in formula['$field']]))"
        line=$line"+$row"
        column_index=$((column_index+1))
    done
    line=$line"+'$ending')"
    printf "%s" "$line"
)

# select the relevant info of the json string provided as first argument, with respect to the fields provided next to it
_select_brew_info() (
    json_brew_info="$1"
    fields="$2"

    if [ -t 1 ]; then # use color when std output is a terminal
        line=$(_build_line "$fields")
    else
        line="print(formula['name']"
        for field in $fields; do
            line=$line"+': '+str(formula['$field'])"
        done
        line=$line")"
    fi
    python_cmd="exec(\"import sys,json\\nfor formula in json.load(sys.stdin): $line\")"

    printf "%s" "$json_brew_info"   \
        | python -c "$python_cmd"
)

# mimic 'brew desc' error message when no formula is provided as argument
_try_brew_arguments() (
    if [ $# -eq 0 ]; then
        brew_desc_error_text="Invalid usage: This command requires a formula argument"
        if [ -t 1 ]; then # use only color when std output is a terminal
            red="\033[0;31m"
            underline="\033[4m"
            ending="\033[0m"
            python -c "print('$red'+'$underline'+'Error'+'$ending'+': $brew_desc_error_text')" >&2
            return 1
        else
            printf "Error: %s\n" "$brew_desc_error_text" >&2
            return 1
        fi
    fi
)

# get values of prescribed 'brew info' field names for each provided homebrew formula(e)
# mimic output format of 'brew desc', including no colorized output when piping
_brew_json() (
    fields="$1"
    shift # all the remaining arguments are expected to be homebrew formula(e)
    formulae="$*"
    # use word splitting of "formulae" when shell is zsh
    # as this option change is run within subshell, no need to keep the current shell option in memory by
    # using the type of solution that nvm needed to use here https://github.com/creationix/nvm/blob/master/nvm.sh#L801-L806
    command -v setopt > /dev/null 2>&1 && setopt shwordsplit
    # shellcheck disable=SC2086
    _try_brew_arguments $formulae || return 1 # reject commands without any formula

    if [ -t 1 ]; then
        # keep std error's colors of 'brew info' if std output is a termina
        # a 'script -q /dev/null' trick together with an 'if/else' is needed in order realize that
        # shellcheck disable=SC2086
        if ! json_brew_info="$(script -q /dev/null brew info --json=v1 $formulae)"; then
            printf "%s\n" "$json_brew_info" >&2
            return 1
        fi
    else
        # shellcheck disable=SC2086
        json_brew_info="$(brew info --json=v1 $formulae)" || return 1
    fi

    _select_brew_info "$json_brew_info" "$fields"
)