add caching to commands

lib/0-utils.sh

@@ -0,0 +1,261 @@
+#!/usr/bin/env bash
+
+# many functions are invoked via variables
+# shellcheck disable=SC2329
+
+# check commands exist
+# "$@" commands to check
+have_cmd() {
+    for cmd in "$@"; do
+        command -v "${cmd}" &>/dev/null || return 1
+    done
+}
+
+# validate results from `jq -r`
+jq_result_valid() {
+    local result="$1"
+    if [[ -z "${result}" || "${result}" == 'null' ]]; then
+        return 1
+    fi
+    return 0
+}
+
+stderr() { echo "$*" 1>&2; }
+info() { stderr "INFO [${FUNCNAME[1]}]: $*"; }
+error() { stderr "ERROR [${FUNCNAME[1]}]: $*"; }
+
+# only echo "$@" if ${DEBUG} is true
+debug() {
+    if [[ ${DEBUG} == false ]]; then
+        return 0
+    fi
+
+    stderr "$@"
+}
+
+# do not do anything
+# if ${DRY_RUN} is enabled
+void() {
+    local cmd=("$@")
+    if [[ ${DRY_RUN} == true ]]; then
+        return 0
+    else
+        "${cmd[@]}"
+        return $?
+    fi
+}
+
+# print out "$@" formatted for bash
+# if ${DRY_RUN} is enabled
+# otherwise, execute the actual command
+dry() {
+    local cmd=("$@")
+    if [[ ${DRY_RUN} == true ]]; then
+        local numCmd="${#cmd[@]}"
+        test "${numCmd}" -eq 0 && return 0
+        local firstLine="'${cmd[0]}'"
+        test "${numCmd}" -gt 1 && firstLine+=' \'
+        stderr "${firstLine}"
+        local earlyStop=$((numCmd - 1))
+        for ((i = 1; i < earlyStop; i++)); do
+            stderr "  '${cmd[${i}]}' \\"
+        done
+        stderr "  '${cmd[${i}]}'"
+    else
+        "${cmd[@]}"
+        return $?
+    fi
+}
+
+# check required utilities for this project
+check_required_utils() {
+    local utils=(
+        base64
+        cat
+        ffprobe
+        jq
+        librelyrics
+        spotify # uv tool install --python 3.8 spotify-cli
+    )
+    local missing=false
+    for util in "${utils[@]}"; do
+        if ! have_cmd "${util}"; then
+            error "missing ${util}!"
+            missing=true
+        fi
+    done
+
+    if [[ ${missing} == true ]]; then
+        return 1
+    else
+        return 0
+    fi
+}
+
+cache_command() {
+    local cmd=("$@")
+    local hash cacheFile cmdOut contents ret
+    hash="$(sha256sum <<<"${cmd[*]}")" || return 1
+    read -r cacheFile _ <<<"${hash}"
+    cacheFilePath="${CACHE_DIR}/${cacheFile}"
+    if [[ -f "${cacheFilePath}" && ${DRY_RUN} == false ]]; then
+        mapfile -t contents <"${cacheFilePath}"
+        ret=$?
+        # skip first line since it is the command
+        printf '%s\n' "${contents[@]:1}"
+    else
+        cmdOut="$(dry "${cmd[@]}")"
+        ret=$?
+        if [[ ${ret} -eq 0 && ${DRY_RUN} == false ]]; then
+            {
+                echo "${cmd[*]}"
+                echo "${cmdOut}"
+            } >"${cacheFilePath}" || return 1
+            echo "${cmdOut}"
+        fi
+    fi
+
+    return "${ret}"
+}
+
+create_tmp_dir() {
+    TMPDIR="$(mktemp -d)" || return 1
+    readonly TMPDIR
+    trap 'rm -rf ${TMPDIR}' EXIT
+}
+
+check_tmp_dir_empty() {
+    for f in "${TMPDIR}"/*; do
+        if [[ -f "${f}" ]]; then
+            error "tempdir ${TMPDIR} is not empty!"
+            error "aborting operation"
+            return 1
+        fi
+    done
+
+    return 0
+}
+
+# librelyrics only exposes a directory to download to
+# so this wrapper function downloads to a directory
+# and then outputs the contents of the downloaded file
+# to stdout so it can effectively be cached
+librelyrics_dl() {
+    local url="$1"
+    check_tmp_dir_empty || return 1
+    librelyrics \
+        --directory "${TMPDIR}" \
+        "${url}" 1>&2
+    local librelyricsRet=$?
+
+    local downloadedFile=''
+    for f in "${TMPDIR}/"*; do
+        if [[ -f "${f}" ]]; then
+            downloadedFile="${f}"
+            break
+        fi
+    done
+
+    if [[ ${librelyricsRet} -eq 0 && -z ${downloadedFile} ]]; then
+        error "failed to download file for ${url} despite no librelyrics error"
+        return 1
+    fi
+
+    local fileContents=''
+    if [[ -n "${downloadedFile}" ]]; then
+        fileContents="$(<"${downloadedFile}")"
+        rm "${downloadedFile}" || return 1
+    fi
+
+    if [[ ${librelyricsRet} -eq 0 && -z ${fileContents} ]]; then
+        error "failed to read file for ${url} despite no librelyrics error"
+        return 1
+    fi
+
+    echo "${fileContents}"
+}
+
+download_with_librelyrics() {
+    local isrc="$1"
+    local output="$2"
+    local urlType="$3"
+
+    if [[ ! "${urlType}" =~ spotify|deezer ]]; then
+        error "only spotify|deezer are supported"
+        return 1
+    fi
+
+    local url=''
+    url="$(get_"${urlType}"_url "${isrc}")" || return 1
+
+    local lyrics=''
+    lyrics="$(cache_command \
+        librelyrics_dl \
+        "${url}")"
+
+    if [[ -z "${lyrics}" ]]; then
+        error "could not get lyrics for ${isrc} using ${urlType}"
+        return 1
+    fi
+
+    info "found lyrics for ${isrc} with ${urlType}"
+    echo "${lyrics}" >"${output}"
+}
+
+output_eval_functions() {
+    while read -r line; do
+        IFS=' ' read -r _ _ function <<<"${line}"
+        [[ "${function}" == '_determine_inputs_'* ||
+            "${function}" == set_default_options ]] || continue
+        ${line}
+    done <<<"$(declare -F)"
+}
+
+get_file_isrc() {
+    local file="$1"
+    local probe='' jqResult=''
+
+    local probe=''
+    probe="$(
+        ffprobe \
+            -v error \
+            -show_entries stream \
+            -of json \
+            "${file}"
+    )" || return 1
+
+    local jqFilter='.streams[] | select(.codec_type == "audio") | .tags | with_entries(.key |= ascii_downcase) | .isrc'
+    jqResult="$(jq -r "${jqFilter}" <<<"${probe}")"
+
+    if [[ "${jqResult}" == 'null' ]]; then
+        error "failed to find ISRC for ${file}"
+        return 1
+    fi
+    echo "${jqResult}"
+}
+
+set_lyric_file_name() {
+    local file="$1"
+    if [[ ! "${file}" =~ ${MUSIC_EXTENSION_REGEX} ]]; then
+        echo "${file} is not a music file"
+        return 1
+    fi
+
+    echo "${file%.opus}.lrc"
+}
+
+is_valid_lrc() {
+    local file="$1"
+
+    test -f "${file}" || return 1
+
+    local valid=0
+    while read -r line; do
+        if [[ "${line}" != '['* ]]; then
+            valid=1
+            break
+        fi
+    done <"${file}"
+
+    return ${valid}
+}