{ config, lib, nixosConfig, pkgs, ... }:
let
  mpv-prescalers = pkgs.fetchFromGitHub {
    owner = "bjin";
    repo = "mpv-prescalers";
    rev = "b37d0f12223720f5ce48e149678162ae0a984176";
    sha256 = "1mmf5827qsyph0wqkyvi7zfng1cskkapngn5hf9073zc61n4398y";

    meta.license = lib.licenses.lgpl3Plus;
  };

  shaders = {
    fsrcnnx_x2 = pkgs.fetchurl {
      name = "FSRCNNX_x2_8-0-4-1.glsl";
      url = "https://web.archive.org/web/20220609155212/https://objects.githubusercontent.com/github-production-release-asset-2e65be/99480330/aa89f8b1-35e1-49b5-8c04-9039d5263eb3?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=AKIAIWNJYAX4CSVEH53A%2F20220609%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20220609T155212Z&X-Amz-Expires=300&X-Amz-Signature=8c60c1bbae7befb9a3f803f286a0471fdad6b77b83cfd87e3ff3b74f0a1bfb3f&X-Amz-SignedHeaders=host&actor_id=0&key_id=0&repo_id=99480330&response-content-disposition=attachment%3B%20filename%3DFSRCNNX_x2_8-0-4-1.glsl&response-content-type=application%2Foctet-stream";
      sha256 = "sha256-6ADbxcHJUYXMgiFsWXckUz/18ogBefJW7vYA8D6Nwq4=";

      meta.license = lib.licenses.mit;
    };

    SSimDownscaler = pkgs.fetchurl {
      url = "https://gist.github.com/igv/36508af3ffc84410fe39761d6969be10/raw/ac09db2c0664150863e85d5a4f9f0106b6443a12/SSimDownscaler.glsl";
      sha256 = "1c3fp6llg0n8zdxadsg6g3kcvhqvikalbc9q61zgwvsx8q3d8rph";

      meta.license = lib.licenses.lgpl3Plus;
    };

    KrigBilateral = pkgs.fetchurl {
      url = "https://gist.github.com/igv/a015fc885d5c22e6891820ad89555637/raw/c471ef6dcbd3c4a977e1c95dc40944ee38fad08a/KrigBilateral.glsl";
      sha256 = "11s0h6i0y3h2nrfp6lax6hzwvjbn93akjr6d61jrmz09zdf1iwmc";

      meta.license = lib.licenses.lgpl3Plus;
    };
  };

  gallery-view = pkgs.fetchFromGitHub {
    owner = "occivink";
    repo = "mpv-gallery-view";
    rev = "eca93f9ff2b8716ac750824c9980f6eb766756cf";
    sha256 = "01ys2nd166lvcppnrch8ls5n6jhrha2z0jcn9hnfip63gvv2c5gn";

    meta.license = lib.licenses.gpl2;
  };

  cycleShaders = shaders: "cycle-values glsl-shaders ${lib.concatStringsSep " " shaders}";
in
{
  programs.mpv = {
    # mpv can also be useful without a display (e.g. for encoding)
    enable = nixosConfig.sbruder.gui.enable || nixosConfig.sbruder.full;

    package = pkgs.wrapMpv
      (pkgs.mpv-unwrapped.override ({
        vapoursynthSupport = true;
        vapoursynth = pkgs.vapoursynth.withPlugins (with pkgs; [
          vapoursynth-mvtools
        ]);
      } // (if (pkgs.lib.versionAtLeast (pkgs.lib.substring 0 5 pkgs.lib.version) "23.05") then {
        # TODO: Remove with 23.05
        ffmpeg_5 = pkgs.ffmpeg_5-full;
      } else {
        ffmpeg = pkgs.ffmpeg-full;
      })))
      {
        scripts = with pkgs.mpvScripts; [
          pitchcontrol
          sponsorblock
        ];
      };

    defaultProfiles = [
      "gpu-hq" # High quality by default
    ];

    config = {
      # Main application font
      osd-font = "monospace";

      # Subtitles (adapted from https://github.com/LightArrowsEXE/dotfiles/blob/75973b6c8493368bbdee6e8e632964045fcf22ec/mpv/.config/mpv/mpv.conf#L76)
      sub-bold = true;
      sub-border-color = "#ff000000";
      sub-border-size = 2.4;
      sub-color = "#ffffff";
      sub-font = "Gandhi Sans"; # see osd-font
      sub-font-size = 50;
      sub-shadow-color = "#a0000000";
      sub-shadow-offset = 0.75;
      sub-use-margins = false;

      # Nicer looking vobsub/PGS subtitles
      sub-gauss = 0.5;
      sub-gray = true;

      # Allow higher volumes
      volume-max = 150;

      # Downmix to stereo by default
      audio-channels = "stereo";

      # Allow seeking in streamed media
      force-seekable = true;

      # Enable hardware decoding when avaliable
      hwdec = "auto-safe";

      # Do not show images only one second
      image-display-duration = "inf";

      # Not too high quality by default (otherwise too high frame drop)
      deband = false;
      dither-depth = "auto";

      # Lossless screenshots
      screenshot-format = "png";

      # Use youtube-dl’s format configuration
      ytdl-format = "ytdl";
    };

    bindings = {
      # Audio filter bs2b (for headphones)
      "b" = "af toggle bs2b";

      # Toggle debanding
      "D" = "cycle deband";

      # Variable correction of audio pitch when changing speed
      "k" = "cycle-values audio-pitch-correction no yes";

      # Reverse cycling for audio and video (shift modifier on german keyboard layout)
      "'" = "cycle audio down";
      "-" = "cycle video down";

      # Cycle between audio downmixes
      "c" = "cycle-values audio-channels stereo mono auto";

      # Cycle between smart scalers (and /dev/null = disabled)
      "K" = cycleShaders
        ((map
          (radius: "${mpv-prescalers}/compute/ravu-r${toString radius}.hook")
          [
            4
            3
            2
          ]) ++ [ "/dev/null" ]);
      "Alt+k" = cycleShaders
        ((map
          (neurons: "${mpv-prescalers}/compute/nnedi3-nns${toString neurons}-win8x4.hook")
          [
            256
            128
            64
            32
            16
          ]) ++ [ "/dev/null" ]);

      # Toggle pitchcontrol
      "Ctrl+p" = "script-message-to pitchcontrol toggle";

      # more granular panning
      "Alt+left" = "add video-pan-x  0.05";
      "Alt+right" = "add video-pan-x -0.05";
      "Alt+up" = "add video-pan-y  0.05";
      "Alt+down" = "add video-pan-y -0.05";

      # sub-delay for fixing 24 empty frames on blu-ray
      "Alt+z" = "add sub-delay -1";
      "Alt+Z" = "add sub-delay +1";

      # sub-delay for fixing exact frame offsets (for signs)
      "Ctrl+z" = "add sub-delay -0.04170833333";
      "Ctrl+Z" = "add sub-delay +0.04170833333";

      # sponsorblock: set segment boundaries
      "alt+g" = "script-binding sponsorblock/set_segment";

      # Exits with error to not mark the video as watched in ytcc
      "Shift+q" = "quit-watch-later 1";
    };

    profiles =
      let
        mkVisualiser = width: height: rate: {
          lavfi-complex = lib.concatStringsSep ";" [
            "[aid1]asplit=4[ao][a1][a2][a3]"
            "[a1]avectorscope=m=lissajous:s=${toString (width / 3)}x${toString (height / 2)}:draw=dot:r=${toString rate}[avectorscope]"
            "[a2]aresample=44100,showwaves=s=${toString (width / 3 * 2)}x${toString (height / 2)}:mode=p2p:colors=red|lightgreen:r=${toString rate}[showwaves]"
            "[a3]showcqt=s=${toString width}x${toString (height / 2)}:axis=0:axis_h=0:r=${toString rate}[showcqt]"
            "[showwaves][avectorscope]hstack=shortest=1[top]"
            "[top][showcqt]vstack=shortest=1,fps=${toString rate}[vo]"
          ];
          alpha = false;
        };
      in
      {
        visualiser = mkVisualiser 1920 1200 30;
        visualiser-60 = mkVisualiser 1920 1200 60;
        visualiser-1080 = mkVisualiser 1920 1080 30;
        visualiser-1080-60 = mkVisualiser 1920 1080 60;
        visualiser-2160 = mkVisualiser 3840 2160 30;
        visualiser-2160-60 = mkVisualiser 3840 2160 60;

        hqencode = {
          ovc = "libx264";
          ovcopts-add = "crf=18";
          oac = "flac";
          audio-format = "s16";
        };

        lq = {
          scale = "bicubic_fast";
          cscale = "bicubic_fast";
          dscale = "bicubic_fast";
        };

        hq = {
          scale = "ewa_lanczossharp";
          dscale = "mitchell";
          linear-downscaling = "no"; # for KrigBilateral
          cscale = "ewa_lanczos";
          glsl-shader = [
            "${shaders.SSimDownscaler}" # dscale
            "${shaders.KrigBilateral}" # cscale
            "${shaders.fsrcnnx_x2}" # scale
          ];
        };

        interpolate = {
          blend-subtitles = true;
          video-sync = "display-resample";
          interpolation = true;
          tscale = "box";
          tscale-window = "sphinx";
          tscale-radius = 1.0;
          tscale-clamp = 0.0;
        };

        mvinterpolate.vf-add = "vapoursynth=${./mvinterpolate.py}";

        # adapted from https://github.com/mpv-player/mpv/issues/4418#issuecomment-368272929
        clear-speed.af-add = "scaletempo=stride=18:overlap=.6:search=10";
      };
  };

  xdg.configFile = {
    # scripts that are incompatible with home-manager’s mechanism
    "mpv/scripts/lib.disable/gallery.lua".source = "${gallery-view}/scripts/lib.disable/gallery.lua";
    "mpv/scripts/playlist-view.lua".source = "${gallery-view}/scripts/playlist-view.lua";

    # script options
    "mpv/script-opts/playlist_view.conf".text = ''
      thumbs_dir=${config.xdg.cacheHome}/thumbnails/mpv
    '';
    "mpv/script-opts/sponsorblock.conf".text = ''
      local_database=no
    '';

    # make ytdl-hook use yt-dlp
    "mpv/script-opts/ytdl_hook.conf".text = ''
      ytdl_path=${pkgs.unstable.yt-dlp}/bin/yt-dlp
    '';

    "mpv/script-opts/stats.conf".text = ''
      font=${config.programs.mpv.config.osd-font}
      font_mono=${config.programs.mpv.config.osd-font}
      font_size=10
      redraw_delay=0.25
    '';
    # mpv-gallery-view’s thumbnail generation mechanism supports multithreading by linking it multiple times
  } // lib.listToAttrs
    (map
      (i: lib.nameValuePair
        "mpv/scripts/gallery-thumbgen-${toString i}.lua"
        { source = "${gallery-view}/scripts/gallery-thumbgen.lua"; })
      (lib.range 1 16));

  # dummy file
  home.file."${config.xdg.cacheHome}/thumbnails/mpv/.create".text = "";
}