Adds first fully working version of code

build.gradle.kts

@@ -0,0 +1,58 @@
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+plugins {
+    id("org.springframework.boot") version "3.2.5"
+    id("io.spring.dependency-management") version "1.1.4"
+    kotlin("jvm") version "1.9.23"
+    kotlin("plugin.spring") version "1.9.23"
+}
+
+group = "net.halfbinary"
+version = "0.0.7-SNAPSHOT"
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_21
+}
+
+configurations {
+    compileOnly {
+        extendsFrom(configurations.annotationProcessor.get())
+    }
+}
+
+repositories {
+    mavenCentral()
+}
+
+val mp3agicVersion = "0.9.1"
+val kotlinLoggingVersion = "6.0.9"
+val slf4jApiVersion = "2.0.13"
+val logbackVersion = "1.5.6"
+val coroutinesVersion = "1.8.1"
+
+dependencies {
+    implementation("org.springframework.boot:spring-boot-starter-web")
+    implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
+    implementation("org.jetbrains.kotlin:kotlin-reflect")
+    implementation("com.mpatric:mp3agic:$mp3agicVersion")
+    implementation("io.github.oshai:kotlin-logging:$kotlinLoggingVersion")
+    implementation("org.slf4j:slf4j-api:$slf4jApiVersion")
+    implementation("ch.qos.logback:logback-core:$logbackVersion")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutinesVersion")
+    developmentOnly("org.springframework.boot:spring-boot-devtools")
+    annotationProcessor("org.springframework.boot:spring-boot-configuration-processor")
+    testImplementation("org.springframework.boot:spring-boot-starter-test")
+    testImplementation("ch.qos.logback:logback-classic:$logbackVersion")
+    testRuntimeOnly("org.junit.platform:junit-platform-launcher")
+}
+
+tasks.withType<KotlinCompile> {
+    kotlinOptions {
+        freeCompilerArgs += "-Xjsr305=strict"
+        jvmTarget = "21"
+    }
+}
+
+tasks.withType<Test> {
+    useJUnitPlatform()
+}

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

gradlew

@@ -0,0 +1,249 @@
+#!/bin/sh
+
+#
+# Copyright © 2015-2021 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd "${APP_HOME:-./}" > /dev/null && pwd -P ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -classpath "$CLASSPATH" \
+        org.gradle.wrapper.GradleWrapperMain \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

gradlew.bat

@@ -0,0 +1,92 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

settings.gradle.kts

@@ -0,0 +1 @@
+rootProject.name = "prettyplayerapi"

src/main/kotlin/net/halfbinary/prettyplayerapi/PrettyplayerapiApplication.kt

@@ -0,0 +1,12 @@
+package net.halfbinary.prettyplayerapi
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+@SpringBootApplication
+class PrettyplayerapiApplication
+
+
+fun main(args: Array<String>) {
+    runApplication<PrettyplayerapiApplication>(*args)
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/controller/AlbumController.kt

@@ -0,0 +1,16 @@
+package net.halfbinary.prettyplayerapi.controller
+
+import net.halfbinary.prettyplayerapi.model.AlbumInfo
+import net.halfbinary.prettyplayerapi.service.AlbumService
+import org.springframework.web.bind.annotation.CrossOrigin
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@CrossOrigin
+class AlbumController(private val albumService: AlbumService) {
+    @GetMapping("albums")
+    fun listFolders(): List<AlbumInfo> {
+        return albumService.getAlbumList()
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/controller/CacheController.kt

@@ -0,0 +1,15 @@
+package net.halfbinary.prettyplayerapi.controller
+
+import net.halfbinary.prettyplayerapi.service.AlbumCacheService
+import org.springframework.web.bind.annotation.CrossOrigin
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@CrossOrigin
+class CacheController(private val albumCacheService: AlbumCacheService) {
+    @GetMapping("cache")
+    fun refreshAlbumCache() {
+        albumCacheService.refreshAlbumCache()
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/controller/FolderController.kt

@@ -0,0 +1,15 @@
+package net.halfbinary.prettyplayerapi.controller
+
+import net.halfbinary.prettyplayerapi.service.FolderService
+import org.springframework.web.bind.annotation.CrossOrigin
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@CrossOrigin
+class FolderController(private val folderService: FolderService) {
+    @GetMapping("folders")
+    fun listFolders(): List<String> {
+        return folderService.getFolderList()
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/controller/ImageController.kt

@@ -0,0 +1,17 @@
+package net.halfbinary.prettyplayerapi.controller
+
+import net.halfbinary.prettyplayerapi.service.ImageService
+import org.springframework.http.MediaType
+import org.springframework.web.bind.annotation.CrossOrigin
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.PathVariable
+import org.springframework.web.bind.annotation.RestController
+
+@RestController
+@CrossOrigin
+class ImageController(private val imageService: ImageService) {
+    @GetMapping(value = ["image/{id}"], produces = [MediaType.IMAGE_JPEG_VALUE])
+    fun getImage(@PathVariable("id") id: String): ByteArray {
+        return imageService.getImage(id).readBytes()
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/controller/MusicController.kt

@@ -0,0 +1,19 @@
+package net.halfbinary.prettyplayerapi.controller
+
+import net.halfbinary.prettyplayerapi.service.MusicService
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.*
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody
+
+@RestController
+@RequestMapping("music")
+@CrossOrigin
+class MusicController(private val musicService: MusicService) {
+
+    @GetMapping(value = ["/album/{albumHash}/{trackNumber}"], produces = ["audio/mpeg3"])
+    fun getAlbum(@PathVariable albumHash: String, @PathVariable trackNumber: Int): ResponseEntity<StreamingResponseBody> {
+        val track = musicService.getMusic(albumHash, trackNumber)
+        val responseBody = StreamingResponseBody { stream -> stream.write(track.readBytes()) }
+        return ResponseEntity.ok().body(responseBody)
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/exception/AlbumHashNotFoundException.kt

@@ -0,0 +1,4 @@
+package net.halfbinary.prettyplayerapi.exception
+
+class AlbumHashNotFoundException(message: String) : RuntimeException(message) {
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/exception/EnvironmentVariableNotFoundException.kt

@@ -0,0 +1,4 @@
+package net.halfbinary.prettyplayerapi.exception
+
+class EnvironmentVariableNotFoundException(message: String) : RuntimeException(message) {
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/exception/GlobalExceptionHandler.kt

@@ -0,0 +1,28 @@
+package net.halfbinary.prettyplayerapi.exception
+
+import org.springframework.http.HttpStatus
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.ControllerAdvice
+import org.springframework.web.bind.annotation.ExceptionHandler
+
+@ControllerAdvice
+class GlobalExceptionHandler {
+    @ExceptionHandler
+    fun handleEnvironmentVariableNotFoundException(e: EnvironmentVariableNotFoundException): ResponseEntity<ErrorResponse> {
+        return ResponseEntity(
+            ErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.value(),
+            e.message ?:""), HttpStatus.INTERNAL_SERVER_ERROR)
+    }
+    @ExceptionHandler
+    fun handleException(e: RuntimeException): ResponseEntity<ErrorResponse> {
+        return ResponseEntity(
+            ErrorResponse(HttpStatus.INTERNAL_SERVER_ERROR.value(),
+            e.message?:""), HttpStatus.INTERNAL_SERVER_ERROR)
+    }
+
+}
+
+data class ErrorResponse(
+    private val responseCode: Int,
+    private val message: String
+)

src/main/kotlin/net/halfbinary/prettyplayerapi/model/AlbumInfo.kt

@@ -0,0 +1,3 @@
+package net.halfbinary.prettyplayerapi.model
+
+data class AlbumInfo(val albumTitle: String, val albumFolder: String, val hash: String)

src/main/kotlin/net/halfbinary/prettyplayerapi/repository/AlbumRepository.kt

@@ -0,0 +1,9 @@
+package net.halfbinary.prettyplayerapi.repository
+
+import net.halfbinary.prettyplayerapi.model.AlbumInfo
+import org.springframework.stereotype.Repository
+
+@Repository
+class AlbumRepository {
+    var albumCache: LinkedHashMap<String, AlbumInfo> = linkedMapOf()
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/AlbumCacheService.kt

@@ -0,0 +1,99 @@
+package net.halfbinary.prettyplayerapi.service
+
+import com.mpatric.mp3agic.Mp3File
+import io.github.oshai.kotlinlogging.KotlinLogging
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.runBlocking
+import net.halfbinary.prettyplayerapi.exception.EnvironmentVariableNotFoundException
+import net.halfbinary.prettyplayerapi.model.AlbumInfo
+import net.halfbinary.prettyplayerapi.repository.AlbumRepository
+import org.springframework.stereotype.Service
+import java.awt.Image
+import java.awt.image.BufferedImage
+import java.io.File
+import java.nio.file.Path
+import javax.imageio.ImageIO
+import kotlin.io.path.name
+
+private val logger = KotlinLogging.logger {}
+
+@Service
+class AlbumCacheService(private val albumRepository: AlbumRepository) {
+
+    fun refreshAlbumCache() {
+        runBlocking{
+            launch { cacheAlbums(true)}
+        }
+    }
+
+    fun getAlbumCache(): LinkedHashMap<String, AlbumInfo> {
+        return albumRepository.albumCache
+    }
+
+    suspend fun cacheAlbums(refresh: Boolean = false) {
+        createAlbumArtRootDir()
+        val list = getAlbumRootDir()
+            .walkTopDown()
+            .filter {
+                it.isFile && it.extension == "mp3" && it.name.startsWith("01.")
+            }
+            .toList()
+            .map { Pair(it, Mp3File(it)) }
+            .sortedWith(getMusicComparator())
+            .map {
+                val folder = it.first.parentFile.toPath()
+                val folderHash = folder.name.hashCode().toString()
+                runBlocking { launch {getAndWriteAlbumImageFile(it.first, folderHash, folder, refresh)} }
+                Pair(folderHash, AlbumInfo(it.second.id3v2Tag.album, it.first.parent, folderHash))
+            }
+
+        albumRepository.albumCache = convertAlbumListToMapForCache(list)
+        logger.info { "Albums cached: ${albumRepository.albumCache.size}" }
+    }
+
+    fun createAlbumArtRootDir() {
+        val root = File(ALBUM_ART_ROOT_DIR)
+        if(!root.exists()) {
+            root.mkdirs()
+        }
+        logger.info { "Album Art Directory: $root" }
+    }
+
+    fun getAlbumRootDir(): File {
+        val root = File(ALBUM_ROOT_DIR)
+        logger.info { "Albums Directory: $root" }
+        return root
+    }
+
+    fun getMusicComparator(): Comparator<Pair<File, Mp3File>> {
+        return compareBy({ it.second.id3v2Tag.albumArtist }, {it.second.id3v2Tag.album}, {it.second.id3v2Tag.year})
+    }
+
+    fun convertAlbumListToMapForCache(list: List<Pair<String, AlbumInfo>>): java.util.LinkedHashMap<String, AlbumInfo> {
+        val array = list.toTypedArray()
+        return linkedMapOf(*array)
+    }
+
+    suspend fun getAndWriteAlbumImageFile(file: File, folderHash: String, folder: Path, refresh: Boolean = false) {
+        val hashedFile = File("$ALBUM_ART_ROOT_DIR/$folderHash.jpg")
+        logger.info { "Looking at $hashedFile" }
+        if(refresh || !hashedFile.exists()) {
+            logger.debug { "No image for $folder, making one..." }
+            val imageByteStream = Mp3File(file).id3v2Tag.albumImage.inputStream()
+            val bufferedImage = ImageIO.read(imageByteStream)
+            val scaledImage = bufferedImage.getScaledInstance(300, 300, Image.SCALE_DEFAULT)
+            val outputImage = BufferedImage(300, 300, BufferedImage.TYPE_INT_RGB)
+            outputImage.graphics.drawImage(scaledImage, 0, 0, null)
+            ImageIO.write(outputImage, "jpg", hashedFile)
+            logger.debug { "Wrote new image file." }
+        }
+    }
+
+    companion object {
+        val ALBUM_ROOT_DIR = System.getenv("ALBUM_ROOT_DIR")
+            ?: throw EnvironmentVariableNotFoundException("Environment variable `ALBUM_ROOT_DIR` does not exist, please specify.") //"q:\\CDs"
+        val ALBUM_ART_ROOT_DIR = System.getenv("ALBUM_ART_ROOT_DIR")
+            ?: throw EnvironmentVariableNotFoundException("Environment variable `ALBUM_ART_ROOT_DIR` does not exist, please specify.") //"src/main/resources/images/"
+    }
+
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/AlbumService.kt

@@ -0,0 +1,11 @@
+package net.halfbinary.prettyplayerapi.service
+
+import net.halfbinary.prettyplayerapi.model.AlbumInfo
+import org.springframework.stereotype.Service
+
+@Service
+class AlbumService(private val albumCacheService: AlbumCacheService) {
+    fun getAlbumList(): List<AlbumInfo> {
+        return albumCacheService.getAlbumCache().map { (_,v) -> v }
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/FolderService.kt

@@ -0,0 +1,10 @@
+package net.halfbinary.prettyplayerapi.service
+
+import org.springframework.stereotype.Service
+
+@Service
+class FolderService(private val albumCacheService: AlbumCacheService) {
+    fun getFolderList(): List<String> {
+        return albumCacheService.getAlbumCache().map { (_,v) -> v.albumFolder }
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/ImageService.kt

@@ -0,0 +1,11 @@
+package net.halfbinary.prettyplayerapi.service
+
+import org.springframework.stereotype.Service
+import java.io.File
+
+@Service
+class ImageService {
+    fun getImage(id: String): File {
+        return File("${AlbumCacheService.ALBUM_ART_ROOT_DIR}/$id.jpg")
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/MusicService.kt

@@ -0,0 +1,17 @@
+package net.halfbinary.prettyplayerapi.service
+
+import net.halfbinary.prettyplayerapi.exception.AlbumHashNotFoundException
+import org.springframework.stereotype.Service
+import java.io.File
+
+@Service
+class MusicService(private val albumCacheService: AlbumCacheService) {
+    fun getMusic(albumHash: String, trackNumber: Int): File {
+        val albumInfo = albumCacheService.getAlbumCache()[albumHash]
+        return if(albumInfo != null) {
+            File(albumInfo.albumFolder).listFiles()[trackNumber-1]
+        } else {
+            throw AlbumHashNotFoundException("Album hash $albumHash not found")
+        }
+    }
+}

src/main/kotlin/net/halfbinary/prettyplayerapi/service/StartupService.kt

@@ -0,0 +1,15 @@
+package net.halfbinary.prettyplayerapi.service
+
+import jakarta.annotation.PostConstruct
+import org.springframework.stereotype.Component
+
+
+@Component
+class StartupService(private val albumCacheService: AlbumCacheService) {
+
+    @PostConstruct
+    fun onStartup() {
+        albumCacheService.refreshAlbumCache()
+    }
+
+}

src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=prettyplayerapi

src/test/kotlin/net/halfbinary/prettyplayerapi/PrettyplayerapiApplicationTests.kt

@@ -0,0 +1,13 @@
+package net.halfbinary.prettyplayerapi
+
+import org.junit.jupiter.api.Test
+import org.springframework.boot.test.context.SpringBootTest
+
+@SpringBootTest
+class PrettyplayerapiApplicationTests {
+
+    @Test
+    fun contextLoads() {
+    }
+
+}