RemSound/src/RemSound.Core/AppConfig.cs

using System.Text.Json;

namespace RemSound.Core;

/// <summary>How often the self-updater polls GitHub Releases for a newer build. Values are
/// stable: don't reorder; deserialisation reads the underlying int from <c>remsound.config.json</c>.</summary>
public enum UpdateCheckFrequency
{
    Never = 0,
    EveryHour = 1,
    Every6Hours = 2,
    Every24Hours = 3,
}

/// <summary>
/// App-level configuration that lives next to the exe as <c>remsound.config.json</c>.
/// Distinct from <see cref="Profile"/>: profiles are user-chosen sets of audio /
/// connectivity / device settings; the app config is the *meta* layer that holds
/// preferences that should be sticky regardless of which profile is loaded. Profiles are
/// per-setup; this file is per-installation.
///
/// What lives here:
///   * <see cref="ProfilesDirectory"/> — where the profile JSONs are read from.
///
/// (Pre-2026-05-11 also held <c>BothModeWarningSuppressed</c> — the "do not show me again"
/// tick on the WASAPI+ASIO latency popup. The popup was retired along with the audio-mode
/// listbox; old config JSONs that still contain the key just have it ignored.)
///
/// Persisted location: <c>&lt;exe&gt;\remsound.config.json</c>. If the file is missing or
/// malformed, defaults are used and the app behaves exactly as it did pre-2026-05-05
/// (per-machine subfolder under the exe). The file is only written when the user
/// explicitly changes a setting.
/// </summary>
public sealed class AppConfig
{
    /// <summary>Filesystem path to the directory the app should read profiles from. When
    /// null, RemSound uses the legacy default: <c>&lt;exe&gt;\profiles\&lt;machine&gt;\</c>.
    /// When set to an explicit folder, that folder IS the profiles folder — no per-machine
    /// subfolder is appended (the user picked it, they meant it; that also lets a user point
    /// at a Dropbox folder shared between machines).</summary>
    public string? ProfilesDirectory { get; set; }

    /// <summary>True if the user has ticked "do not show me this message again" on the
    /// confirmation popup that fires when Save (Ctrl+S / File → Save) successfully
    /// overwrites the currently-loaded profile. Lives here (not in Profile) so the
    /// preference sticks across profile switches — once you've decided you don't need
    /// the "Profile saved" nag, you don't expect it to come back when you load a
    /// different profile. The Save-As path doesn't use this flag: the Save-As dialog
    /// itself is the user-visible confirmation, so a follow-up popup is redundant.</summary>
    public bool SaveProfileConfirmationSuppressed { get; set; }

    /// <summary>True if the user has ticked "do not show me this message again" on the
    /// "you are saving onto a read-only profile" warning. Once ticked, Ctrl+S / File → Save
    /// on a read-only profile saves silently through the lock instead of warning first.
    /// Machine-local (not per-profile) so the preference sticks across profile switches; the
    /// prompt itself is the same wording on any read-only profile so a single dismissal
    /// applies everywhere. 2026-05-23 — semantic shift from v2.x: in v2.x the read-only lock
    /// hard-blocked explicit saves and this flag suppressed the explanatory "save was skipped"
    /// popup. In v3.0 the lock only suppresses the automatic "you have unsaved changes" prompt
    /// on close / profile switch; explicit Ctrl+S / File → Save now goes through with a
    /// one-time warning gated by this flag. The JSON key was renamed alongside the semantic
    /// change so users upgrading from v2.x see the new warning at least once — a v2.x
    /// suppression flag is no longer applicable and is silently discarded on load.</summary>
    public bool SaveOnReadOnlyWarningSuppressed { get; set; }

    /// <summary>If true, RemSound minimises to the system tray immediately after the main
    /// window finishes loading. Lets the user "boot up the machine and have RemSound
    /// already running quietly". Default false.</summary>
    public bool StartMinimised { get; set; }

    /// <summary>If true (the default), the main window shows a "Volume, pan and EQ for peers" tab
    /// (positioned before "Audio profile") for setting per-peer volume, panning and EQ. Toggled by
    /// "Show the volume, pan and EQ for peers tab" on the Preferences General tab. Machine-wide (a
    /// UI-visibility preference, like which tabs exist) — the shaping VALUES are saved per profile, in
    /// <see cref="Profile.PeerShaping"/>.</summary>
    public bool ShowPanEqTab { get; set; } = true;

    /// <summary>If true (the default), RemSound plays the startup cue once, right after this
    /// copy wins the single-instance takeover and before the profile loads. Machine-wide (not
    /// per-<see cref="Profile"/>) because it fires before any profile — and its per-profile
    /// custom-cue dictionary — has been chosen. Like the connect/disconnect cues it's audible
    /// feedback, on by default; the user unticks "Startup sound" in Preferences to silence it.
    /// (The usual "auto-options default off" rule is about data-persistence toggles, not cues.)</summary>
    public bool EnableStartupCue { get; set; } = true;

    /// <summary>Optional custom WAV path for the startup cue. Null = use the bundled
    /// <c>sounds\start up.wav</c>. Machine-wide for the same reason as
    /// <see cref="EnableStartupCue"/>: the cue plays before any profile (and the per-profile
    /// custom-cue paths) is loaded, so it can't live on <see cref="Profile"/>.</summary>
    public string? StartupCueCustomPath { get; set; }

    /// <summary>The chosen default-sound FILENAME for each cue (e.g. "connect 2.wav"), keyed by
    /// the cue id (<c>MainForm.CueId</c>). The cue WAVs ship as numbered variants ("connect 1.wav",
    /// "connect 2.wav", ...); this records which one the user picked in Preferences. Machine-wide,
    /// so a user's preferred sound palette follows them across every profile. A cue absent from the
    /// dictionary uses the first available variant (the "1"s) by default. A per-profile custom WAV
    /// (<see cref="Profile.CustomCuePaths"/>) still overrides this choice.</summary>
    public Dictionary<string, string> DefaultCueSounds { get; set; } = new();

    /// <summary>If true (the default), typing into any edit field anywhere in RemSound plays a soft
    /// keyboard-click sound (one of several, picked at random), so a screen-reader user gets audible
    /// typing feedback. Password fields additionally play a distinct key sound at the same time.
    /// Machine-wide; the user unticks "Play keyboard clicks" in Preferences to silence it.</summary>
    public bool EnableKeyboardClicks { get; set; } = true;

    /// <summary>Per-cue enable flags for the machine-wide cues added 2026-06-13: the send/receive
    /// on/off toggle cues and the minimise(hide)/restore(show) cues. Machine-wide (like the startup
    /// cue) rather than per-profile - they're app-level feedback for an action, not a per-profile
    /// audio setting. All default on; the user unticks them in Preferences like any other cue.</summary>
    public bool EnableSendOnCue { get; set; } = true;
    public bool EnableSendOffCue { get; set; } = true;
    public bool EnableReceiveOnCue { get; set; } = true;
    public bool EnableReceiveOffCue { get; set; } = true;
    public bool EnableHideCue { get; set; } = true;
    public bool EnableShowCue { get; set; } = true;
    /// <summary>Tick / untick sounds played on every checkbox toggle anywhere in the app.</summary>
    public bool EnableCheckboxOnCue { get; set; } = true;
    public bool EnableCheckboxOffCue { get; set; } = true;
    /// <summary>Sound played whenever the user switches between tabs anywhere in the app (the main
    /// window's tab strip and every tabbed dialog). Machine-wide, default on.</summary>
    public bool EnableTabSwitchCue { get; set; } = true;

    /// <summary>Custom WAV overrides for the machine-wide cues above, keyed by cue id. The
    /// equivalent of <see cref="Profile.CustomCuePaths"/> but machine-wide, since these cues don't
    /// live on a profile. Empty = use the chosen default variant. The startup cue keeps its own
    /// <see cref="StartupCueCustomPath"/> field for backward compatibility.</summary>
    public Dictionary<string, string> MachineCueCustomPaths { get; set; } = new();

    /// <summary>If true, RemSound writes a tab-separated diagnostic log to
    /// <c>&lt;exe&gt;\logs\</c>. Lives here (not in <see cref="Profile"/>) because logging
    /// is a debugging affordance for the installation, not a user-facing audio preference —
    /// switching profiles shouldn't accidentally re-enable a flood of writes the user had
    /// turned off, and a one-machine "yes log everything" decision shouldn't have to ride
    /// along on every saved profile. Default false: no log file is created until the user
    /// ticks <em>Enable logs</em> in the Preferences dialog.</summary>
    public bool LoggingEnabled { get; set; }

    /// <summary>If true, RemSound checks the total size of the <c>logs\</c> folder at startup and,
    /// when it exceeds <see cref="LogsFolderWarnThresholdMb"/> megabytes, shows a one-time warning so
    /// the user can prune or clear it. Off by default (opt-in, like the other behaviour toggles).
    /// Machine-local — a "watch my disk on this box" decision, not a per-profile audio setting.</summary>
    public bool WarnIfLogsFolderExceeds { get; set; }

    /// <summary>The size threshold in megabytes for <see cref="WarnIfLogsFolderExceeds"/>. Default
    /// 100 MB. Only consulted when that flag is on.</summary>
    public int LogsFolderWarnThresholdMb { get; set; } = 100;

    /// <summary>If true, RemSound deletes log files older than <see cref="PruneOldLogsDays"/> days
    /// from the <c>logs\</c> folder at startup. Off by default (opt-in). The currently-open log file
    /// is never a candidate (it's today's). Machine-local.</summary>
    public bool PruneOldLogs { get; set; }

    /// <summary>Age in days for <see cref="PruneOldLogs"/>: log files last written more than this many
    /// days ago are deleted at startup. Range 1–30, default 14. Only consulted when that flag is on.</summary>
    public int PruneOldLogsDays { get; set; } = 14;

    /// <summary>The keyboard shortcuts, machine-wide as of v4.4. Before v4.4 these lived on each
    /// <see cref="Profile"/>, so a shortcut set on one profile didn't apply on another (issue #14).
    /// They now live here — one set shared by every profile, loaded/saved via
    /// <see cref="RemSoundSettingsStore"/>'s Load*/Save* hotkey methods. Null = use the built-in default
    /// for that action. The old per-profile <see cref="HotkeyRecord"/> fields on <see cref="Profile"/>
    /// are kept only so old profile JSONs still deserialise; they are no longer read or written.</summary>
    public HotkeyRecord? ReceiveMuteHotkey { get; set; }
    public HotkeyRecord? SendMuteHotkey { get; set; }
    public HotkeyRecord? TrayHotkey { get; set; }
    public HotkeyRecord? VolumeUpHotkey { get; set; }
    public HotkeyRecord? VolumeDownHotkey { get; set; }
    public HotkeyRecord? ToggleRecordingHotkey { get; set; }
    public HotkeyRecord? RemoteVolumeUpHotkey { get; set; }
    public HotkeyRecord? RemoteVolumeDownHotkey { get; set; }
    public HotkeyRecord? RemoteMuteToggleHotkey { get; set; }
    public HotkeyRecord? SystemVolumeUpHotkey { get; set; }
    public HotkeyRecord? SystemVolumeDownHotkey { get; set; }
    public HotkeyRecord? SystemMuteToggleHotkey { get; set; }
    public HotkeyRecord? QuickProfileSwitchHotkey { get; set; }
    public HotkeyRecord? SpeakStatusLineHotkey { get; set; }
    /// <summary>Global shortcut that toggles the "Enable volume, pan and EQ for all peers" master
    /// switch. Machine-wide and unset by default; NOT stored in any profile (unlike the shaping
    /// values). The user binds it in Keyboard shortcuts.</summary>
    public HotkeyRecord? ToggleAllPeerShapingHotkey { get; set; }

    /// <summary>True once the one-time "your keyboard shortcuts are now shared across profiles" notice
    /// has been shown (to an upgrader), or silently marked done on a fresh install that had nothing to
    /// reset. Stops the notice re-appearing. v4.4. (Superseded by the import offer below; kept so the
    /// flag on an existing v4.4 config still deserialises.)</summary>
    public bool KeyboardShortcutsGlobalNoticeShown { get; set; }

    /// <summary>True once the one-time "bring your keyboard shortcuts across?" import offer has been
    /// resolved (the user chose to import from a profile, or to start fresh). Deliberately SEPARATE from
    /// <see cref="KeyboardShortcutsGlobalNoticeShown"/> so that users who already updated to v4.4 (and
    /// were reset) are STILL offered the chance to import their old per-profile shortcuts — which remain
    /// readable in their profile files.</summary>
    public bool KeyboardShortcutsImportOffered { get; set; }

    /// <summary>If true, the "Use Windows default output" follower at the top of the received-sound
    /// output list is ticked at startup, so received sound plays to whatever Windows currently calls
    /// the default output and re-routes when that changes (plug in headphones, it follows). Unlike a
    /// specific device tick — which can go stale and play to the wrong card — a follower can never be
    /// wrong, so it's safe to persist. Default false (opt-in). <see cref="UseDefaultInputDevice"/> is
    /// the same idea for the send-input list.</summary>
    public bool UseDefaultOutputDevice { get; set; }
    public bool UseDefaultInputDevice { get; set; }

    /// <summary>Remembered answer to the "untick the other outputs/inputs when you turn on Use Windows
    /// default?" prompt. Null = ask each time; true = always untick; false = never untick. Set when the
    /// user ticks "Don't ask again" on that prompt. Machine-wide.</summary>
    public bool? UntickOthersWhenUsingDefaultOutput { get; set; }
    public bool? UntickOthersWhenUsingDefaultInput { get; set; }

    /// <summary>If non-null and a profile with this title exists, RemSound skips the
    /// startup profile picker and loads this profile directly. Combine with
    /// <see cref="StartMinimised"/> + the Windows auto-start registry entry
    /// (see <c>StartupAutoStart</c>) to get a fully unattended boot-into-streaming flow.
    /// To re-show the picker temporarily, untick "Start with a specific profile" in the
    /// Startup behaviour dialog. Null = always show the picker (legacy behaviour).</summary>
    public string? StartWithProfileTitle { get; set; }

    /// <summary>How often RemSound polls the GitHub Releases API for a newer build. Default
    /// <see cref="UpdateCheckFrequency.Every24Hours"/>. Set to <see cref="UpdateCheckFrequency.Never"/>
    /// to disable background checks entirely (the user can still trigger a manual check via
    /// the Preferences button or the Help menu).</summary>
    public UpdateCheckFrequency UpdateCheckFrequency { get; set; } = UpdateCheckFrequency.Every24Hours;

    /// <summary>If true, RemSound downloads and applies a new release without prompting:
    /// the running instance writes the new files to a staging folder, spawns a small
    /// detached helper that waits for the exe to exit, swaps in the new files, and restarts
    /// RemSound. Default false — the user gets a confirmation dialog before each install.</summary>
    public bool SilentlyInstallUpdates { get; set; }

    /// <summary>If true (the default), RemSound runs an update check shortly after launch in
    /// addition to whatever <see cref="UpdateCheckFrequency"/> drives in the background. The
    /// startup check is what catches users who quit and re-open the app within the polling
    /// interval — without it they could miss an update for hours. Set to false to disable the
    /// startup check; the periodic timer (if set) still runs.</summary>
    public bool CheckForUpdatesOnStartup { get; set; } = true;

    /// <summary>If true, RemSound opens the About box (which leads with the latest release
    /// notes) once on the first launch AFTER an update has been installed, so the user sees
    /// "what's new" without going looking. Default false — opt-in. Detected by comparing the
    /// running version against <see cref="LastWhatsNewVersion"/> at launch, so it only fires
    /// when the version actually changed, never on an ordinary relaunch. On by default — it's a
    /// discoverability aid (see what changed), not a data-persistence toggle, so the usual
    /// "auto-options default off" rule doesn't really apply; users can untick it.</summary>
    public bool ShowWhatsNewAfterUpdate { get; set; } = true;

    /// <summary>The app version recorded at the last launch. Used only to detect "the version
    /// changed since last run" for <see cref="ShowWhatsNewAfterUpdate"/>. Null until first
    /// recorded, so a fresh install never counts as an update.</summary>
    public string? LastWhatsNewVersion { get; set; }

    /// <summary>If true, RemSound tries to open the audio port (UDP 47830) on the local router
    /// using UPnP / NAT-PMP / PCP, so peers on the public internet can reach this machine
    /// without manual port forwarding. Default false — the toggle opt-in only, because some
    /// networks (corporate, hostile shared) shouldn't have apps poking the router. When
    /// successful, RemSound surfaces the external address in the Preferences dialog so the
    /// user knows what to give peers. Falls back gracefully when the router doesn't support
    /// UPnP — RemSound just doesn't open anything.</summary>
    public bool UpnpEnabled { get; set; }

    /// <summary>UTC timestamp of the last successful update check. Used by the background
    /// update timer to space out polls across launches — if you set the frequency to
    /// "every 24 hours" and re-launch the app three times that day, it still hits the API
    /// only once. Null on a fresh install.</summary>
    public DateTime? LastUpdateCheckUtc { get; set; }

    /// <summary>Most-recently-opened profile paths, newest first, capped at
    /// <see cref="MaxRecentProfiles"/>. Populated by <see cref="NoteRecentProfile"/> every
    /// time a profile is loaded, surfaced in the File → Recent profiles submenu. Stored as
    /// full paths so profiles saved outside the canonical profiles folder are also
    /// reachable (Save-As to an arbitrary path stays in the recents list).</summary>
    public List<string> RecentProfiles { get; set; } = new();

    /// <summary>Cap on how many entries we keep in <see cref="RecentProfiles"/>. Five is the
    /// most that fits comfortably as 1–5 single-digit mnemonics inside a submenu without
    /// the user needing to read the names to remember which row they want.</summary>
    public const int MaxRecentProfiles = 5;

    /// <summary>Push a profile path to the front of the recents list. Removes any existing
    /// entry that matches (case-insensitive) so a recently re-opened profile rises to the
    /// top instead of being duplicated. Caps the list at <see cref="MaxRecentProfiles"/>.
    /// Caller must <see cref="Save"/> after mutating.</summary>
    public void NoteRecentProfile(string? path)
    {
        if (string.IsNullOrWhiteSpace(path)) return;
        RecentProfiles.RemoveAll(p => string.Equals(p, path, StringComparison.OrdinalIgnoreCase));
        RecentProfiles.Insert(0, path);
        while (RecentProfiles.Count > MaxRecentProfiles)
        {
            RecentProfiles.RemoveAt(RecentProfiles.Count - 1);
        }
    }

    /// <summary>Friendly names of ASIO drivers RemSound must never touch — it won't probe them,
    /// won't list them in the driver picker, and won't open them for streaming. Global (not
    /// per-profile) because "this driver is broken on this machine" is about the hardware/driver
    /// install, not any one profile. Populated when the user answers "yes" to the Realtek-ASIO
    /// compatibility warning, or toggles the Options-menu entry. Matched case-insensitively.</summary>
    public List<string> DisabledAsioDrivers { get; set; } = new();

    /// <summary>Friendly names of ASIO drivers RemSound has already shown its compatibility warning
    /// for, so a user who answered "no, keep using it" isn't nagged on every launch. Independent of
    /// <see cref="DisabledAsioDrivers"/>: a driver can be warned-about-but-still-enabled.</summary>
    public List<string> AsioDriversWarnedAbout { get; set; } = new();

    /// <summary>True if RemSound should refuse to interact with the named ASIO driver in any way.</summary>
    public bool IsAsioDriverDisabled(string? driverName) =>
        !string.IsNullOrWhiteSpace(driverName)
        && DisabledAsioDrivers.Exists(d => string.Equals(d, driverName, StringComparison.OrdinalIgnoreCase));

    /// <summary>Disable or re-enable the named ASIO driver. Caller must <see cref="Save"/> after.</summary>
    public void SetAsioDriverDisabled(string driverName, bool disabled)
    {
        if (string.IsNullOrWhiteSpace(driverName)) return;
        DisabledAsioDrivers.RemoveAll(d => string.Equals(d, driverName, StringComparison.OrdinalIgnoreCase));
        if (disabled) DisabledAsioDrivers.Add(driverName);
    }

    /// <summary>True once the compatibility warning has been shown for this driver. Case-insensitive.</summary>
    public bool HasWarnedAboutAsioDriver(string driverName) =>
        AsioDriversWarnedAbout.Exists(d => string.Equals(d, driverName, StringComparison.OrdinalIgnoreCase));

    /// <summary>Record that the compatibility warning has been shown for this driver (so we don't
    /// re-nag a user who chose to keep it). Caller must <see cref="Save"/> after.</summary>
    public void MarkAsioDriverWarned(string driverName)
    {
        if (string.IsNullOrWhiteSpace(driverName)) return;
        if (!HasWarnedAboutAsioDriver(driverName)) AsioDriversWarnedAbout.Add(driverName);
    }

    /// <summary>True if the named ASIO driver looks like a Realtek HD Audio ASIO driver (its name
    /// or description contains "Realtek"). Realtek's bundled ASIO driver (rthdasio64.dll) leaks OS
    /// handles on every open and is broadly known to misbehave with ASIO hosts; ASUS and other OEMs
    /// ship the same Realtek driver under their own branding, so we match "Realtek" anywhere in the
    /// name. RemSound uses this to proactively offer to disable the driver.</summary>
    public static bool IsRealtekAsioDriver(string? driverName) =>
        !string.IsNullOrWhiteSpace(driverName)
        && driverName.Contains("Realtek", StringComparison.OrdinalIgnoreCase);

    /// <summary>The single per-user folder next to the exe — <c>&lt;exe&gt;\user settings and logs\</c> —
    /// that holds EVERYTHING this machine's user owns: the global config file, the <c>profiles\</c>
    /// subfolder, <c>logs\</c>, and <c>sounds\</c>. 2026-06-10: consolidated here from the loose files
    /// / the earlier <c>config\</c> folder so the install root stays tidy and the auto-updater can
    /// exclude one folder to leave ALL user state (including custom cue WAVs) untouched.</summary>
    public const string UserDataFolderName = "user settings and logs";

    /// <summary>Process-wide override for <see cref="UserDataDirectory"/>. Null = the default
    /// folder next to the exe. Set once at startup from the <c>--config-dir</c> switch so the test
    /// suite (and a portable layout) can point ALL user state - config, profiles, logs, cue sounds -
    /// at an explicit throwaway folder without touching the user's real settings. Must be set before
    /// anything reads config/profiles/logs/sounds.</summary>
    private static string? _userDataDirectoryOverride;

    /// <summary>Redirect every user-state folder to <paramref name="path"/> for this process only.
    /// Call before <see cref="MigrateLegacyLayoutIfNeeded"/> / any config read. Idempotent.</summary>
    public static void SetUserDataDirectoryOverride(string path)
    {
        if (!string.IsNullOrWhiteSpace(path)) _userDataDirectoryOverride = Path.GetFullPath(path);
    }

    public static string UserDataDirectory =>
        _userDataDirectoryOverride ?? Path.Combine(AppContext.BaseDirectory, UserDataFolderName);

    /// <summary>Where the per-machine log files are written.</summary>
    public static string LogsDirectory => Path.Combine(UserDataDirectory, "logs");

    /// <summary>Where the shipped DEFAULT cue WAVs live: a <c>default sounds\</c> folder next to the
    /// exe. This is part of the INSTALL, not user state — the auto-updater (and a dev republish)
    /// always overwrites it, so a changed default sound reaches every user, including existing ones.
    /// Deliberately NOT under <see cref="UserDataDirectory"/> and NOT redirected by <c>--config-dir</c>:
    /// these are shipped defaults, not per-user data. The user's OWN custom sounds are never stored
    /// here — they're explicit file paths (the Preferences "Browse" picker) that live in the user's
    /// own location, which the updater never touches. 2026-06-13: moved here out of the per-user
    /// <c>sounds\</c> folder, whose never-overwrite seeding meant a tweaked default could never land
    /// for anyone who already had the old one.</summary>
    public static string SoundsDirectory => Path.Combine(AppContext.BaseDirectory, "default sounds");

    /// <summary>The OLD per-user sounds folder (<c>...\user settings and logs\sounds\</c>), now
    /// defunct after sounds moved to the install-side <see cref="SoundsDirectory"/>. Kept only so the
    /// startup migration can delete the orphan. Do NOT read cues from here.</summary>
    public static string LegacyUserSoundsDirectory => Path.Combine(UserDataDirectory, "sounds");

    /// <summary>The base profiles folder (ProfileStore appends the per-machine subfolder).</summary>
    public static string ProfilesBaseDirectory => Path.Combine(UserDataDirectory, "profiles");

    private static string ConfigPath => Path.Combine(UserDataDirectory, "global config.json");

    /// <summary>What <see cref="MigrateLegacyLayoutIfNeeded"/> relocated this launch. True only on the
    /// one launch where an older layout was found and moved — the caller uses it to show a one-time
    /// "everything moved" notice.</summary>
    public readonly record struct LayoutMigrationResult(bool MovedAnything);

    /// <summary>
    /// One-time, idempotent consolidation of EVERY older layout into
    /// <c>&lt;exe&gt;\user settings and logs\</c>. Handles all the field permutations, each move guarded
    /// by "source exists AND destination doesn't" so it's safe to run every launch and never clobbers
    /// already-migrated data:
    ///   * global config: <c>&lt;exe&gt;\remsound.config.json</c> (oldest) OR
    ///                     <c>&lt;exe&gt;\config\global config.json</c> (the 2026-06-07 interim layout)
    ///   * profiles:       <c>&lt;exe&gt;\config\profiles\</c> (interim) OR <c>&lt;exe&gt;\profiles\</c> (oldest)
    ///   * logs:           <c>&lt;exe&gt;\logs\</c>
    /// → all under <c>...\user settings and logs\</c>. (Sounds are NOT part of this folder any more —
    /// the shipped defaults live install-side in <see cref="SoundsDirectory"/>; Program deletes the
    /// two orphaned old sounds folders on startup.) Runs BEFORE anything reads config/profiles/
    /// logs. A custom <see cref="ProfilesDirectory"/> is untouched. Directory moves fall back to
    /// copy-then-delete across a volume boundary.
    /// </summary>
    public static LayoutMigrationResult MigrateLegacyLayoutIfNeeded()
    {
        var moved = false;
        try
        {
            Directory.CreateDirectory(UserDataDirectory);
            var root = AppContext.BaseDirectory;
            var interimConfigDir = Path.Combine(root, "config");

            // Global config — interim location wins over the oldest loose file.
            if (!File.Exists(ConfigPath))
            {
                var interimGlobal = Path.Combine(interimConfigDir, "global config.json");
                var oldestGlobal = Path.Combine(root, "remsound.config.json");
                if (File.Exists(interimGlobal)) { File.Move(interimGlobal, ConfigPath); moved = true; }
                else if (File.Exists(oldestGlobal)) { File.Move(oldestGlobal, ConfigPath); moved = true; }
            }

            // Profiles — interim location wins over the oldest.
            if (!Directory.Exists(ProfilesBaseDirectory))
            {
                var interimProfiles = Path.Combine(interimConfigDir, "profiles");
                var oldestProfiles = Path.Combine(root, "profiles");
                if (Directory.Exists(interimProfiles)) { MoveDirectoryResilient(interimProfiles, ProfilesBaseDirectory); moved = true; }
                else if (Directory.Exists(oldestProfiles)) { MoveDirectoryResilient(oldestProfiles, ProfilesBaseDirectory); moved = true; }
            }

            // Logs (only ever lived loose in the root).
            var oldLogs = Path.Combine(root, "logs");
            if (Directory.Exists(oldLogs) && !Directory.Exists(LogsDirectory)) { MoveDirectoryResilient(oldLogs, LogsDirectory); moved = true; }

            // Remove the now-empty 2026-06-07 interim config\ folder.
            try
            {
                if (Directory.Exists(interimConfigDir) && Directory.GetFileSystemEntries(interimConfigDir).Length == 0)
                    Directory.Delete(interimConfigDir);
            }
            catch { /* leave it if it isn't empty / can't be removed */ }
        }
        catch
        {
            // Best-effort: a failed move (permissions, file in use) just means the app falls
            // back to defaults / an empty profiles list rather than crashing on launch.
        }
        return new LayoutMigrationResult(moved);
    }

    /// <summary>Move a directory, falling back to recursive copy-then-delete when a plain
    /// <see cref="Directory.Move"/> can't cross a volume boundary (e.g. the user-data folder is a
    /// junction onto another drive). Copy uses overwrite:false so an already-present destination
    /// file is never clobbered.</summary>
    private static void MoveDirectoryResilient(string source, string dest)
    {
        try { Directory.Move(source, dest); }
        catch (IOException)
        {
            CopyDirectoryRecursive(source, dest);
            try { Directory.Delete(source, recursive: true); } catch { /* copy succeeded; leaving the source is harmless */ }
        }
    }

    private static void CopyDirectoryRecursive(string source, string dest)
    {
        Directory.CreateDirectory(dest);
        foreach (var file in Directory.GetFiles(source))
            File.Copy(file, Path.Combine(dest, Path.GetFileName(file)), overwrite: false);
        foreach (var dir in Directory.GetDirectories(source))
            CopyDirectoryRecursive(dir, Path.Combine(dest, Path.GetFileName(dir)));
    }

    /// <summary>Reads the app config from disk. Always returns a non-null instance — a missing
    /// or malformed file becomes a defaults-only AppConfig rather than throwing.</summary>
    public static AppConfig Load()
    {
        try
        {
            if (!File.Exists(ConfigPath)) return new AppConfig();
            var json = File.ReadAllText(ConfigPath);
            return JsonSerializer.Deserialize<AppConfig>(json) ?? new AppConfig();
        }
        catch
        {
            // Corrupt config file shouldn't keep RemSound from launching. Fall back to
            // defaults; the user can re-pick a folder via the dialog and we'll overwrite
            // the bad file on the next save.
            return new AppConfig();
        }
    }

    /// <summary>Writes this config to disk. Throws on filesystem failures (caller should
    /// surface a MessageBox — failure to persist a directory choice is user-visible).</summary>
    public void Save()
    {
        Directory.CreateDirectory(UserDataDirectory);
        var json = JsonSerializer.Serialize(this, new JsonSerializerOptions { WriteIndented = true });
        // Atomic replace — write a temp then move it over, so a torn write (crash / power-loss /
        // the updater force-closing us mid-save) can't truncate the file and silently revert config
        // to defaults.
        var tmp = ConfigPath + ".tmp";
        try
        {
            File.WriteAllText(tmp, json);
            File.Move(tmp, ConfigPath, overwrite: true);
        }
        catch
        {
            try { if (File.Exists(tmp)) File.Delete(tmp); } catch { /* ignore */ }
            throw;
        }
    }

    /// <summary>Convenience: build the appropriate <see cref="ProfileStore"/> for the
    /// current config. Falls back to the default store (per-machine subfolder) if the
    /// configured folder is missing, blank, or doesn't exist on disk.</summary>
    public ProfileStore CreateStore()
    {
        if (!string.IsNullOrWhiteSpace(ProfilesDirectory) && Directory.Exists(ProfilesDirectory))
        {
            return new ProfileStore(ProfilesDirectory);
        }
        return new ProfileStore();
    }
}