# Legacy impermanence module for defiant
# See legacy-storage.nix for the full incremental migration plan.
#
# This file is consumed in two phases:
#
# Phase 3 (after generateBase is enabled):
#   Remove the SYSTEM-LEVEL entries marked [PHASE 3] below. These will be
#   handled automatically by storage.nix, ssh.nix, and the impermanence module:
#     - var-lib-private-permissions activation script
#     - /etc/machine-id
#     - SSH host keys
#     - /var/lib/nixos
#     - /var/lib/systemd/coredump
#     - /persist/system/var/log persistence block
#
# Phase 4 (migrate services one at a time, any order):
#   For each service:
#     1. Remove the service's section marked [PHASE 4] from this file
#     2. Remove `impermanence.enable = false` for that service in configuration.nix
#   For jellyfin/qbittorrent, also remove the separate media persistence blocks.
#
# Phase 5: Delete this file once empty.
{
  config,
  lib,
  ...
}: {
  config = lib.mkIf config.storage.impermanence.enable {
    # [PHASE 3] Remove this activation script after enabling generateBase
    system.activationScripts = {
      "var-lib-private-permissions" = {
        deps = ["specialfs"];
        text = ''
          mkdir -p /persist/system/root/var/lib/private
          chmod 0700 /persist/system/root/var/lib/private
        '';
      };
    };

    environment.persistence."/persist/system/root" = {
      enable = true;
      hideMounts = true;
      # [PHASE 3] Remove this files block after enabling generateBase
      files = lib.mkMerge [
        ["/etc/machine-id"]
        # SSH host keys
        (lib.mkIf config.services.openssh.enable (
          lib.lists.flatten (
            builtins.map (hostKey: [
              hostKey.path
              "${hostKey.path}.pub"
            ])
            config.services.openssh.hostKeys
          )
        ))
      ];
      directories = lib.mkMerge [
        # [PHASE 3] Remove these system directories after enabling generateBase
        [
          "/var/lib/nixos"
          "/var/lib/systemd/coredump"
        ]

        # [PHASE 4] PostgreSQL
        (lib.mkIf config.services.postgresql.enable [
          {
            directory = "/var/lib/postgresql/16";
            user = "postgres";
            group = "postgres";
          }
        ])

        # [PHASE 4] Reverse Proxy (ACME)
        (lib.mkIf config.services.reverseProxy.enable [
          {
            directory = "/var/lib/acme";
            user = "acme";
            group = "acme";
          }
        ])

        # [PHASE 4] Ollama
        (lib.mkIf config.services.ollama.enable [
          {
            directory = "/var/lib/private/ollama";
            user = config.services.ollama.user;
            group = config.services.ollama.group;
            mode = "0700";
          }
        ])

        # [PHASE 4] Tailscale
        (lib.mkIf config.services.tailscale.enable [
          {
            directory = "/var/lib/tailscale";
            user = "root";
            group = "root";
          }
        ])

        # [PHASE 4] Syncthing
        (lib.mkIf config.services.syncthing.enable [
          {
            directory = "/mnt/sync";
            user = "syncthing";
            group = "syncthing";
          }
          {
            directory = "/etc/syncthing";
            user = "syncthing";
            group = "syncthing";
          }
        ])

        # [PHASE 4] Fail2ban
        (lib.mkIf config.services.fail2ban.enable [
          {
            directory = "/var/lib/fail2ban";
            user = "fail2ban";
            group = "fail2ban";
          }
        ])

        # [PHASE 4] Jellyfin (data/cache only - media is on separate dataset)
        (lib.mkIf config.services.jellyfin.enable [
          {
            directory = "/var/lib/jellyfin";
            user = "jellyfin";
            group = "jellyfin";
          }
          {
            directory = "/var/cache/jellyfin";
            user = "jellyfin";
            group = "jellyfin";
          }
        ])

        # [PHASE 4] Immich
        (lib.mkIf config.services.immich.enable [
          {
            directory = "/var/lib/immich";
            user = "immich";
            group = "immich";
          }
        ])

        # [PHASE 4] Forgejo
        (lib.mkIf config.services.forgejo.enable [
          {
            directory = "/var/lib/forgejo";
            user = "forgejo";
            group = "forgejo";
          }
        ])

        # [PHASE 4] Actual
        (lib.mkIf config.services.actual.enable [
          {
            directory = "/var/lib/private/actual";
            user = "actual";
            group = "actual";
          }
        ])

        # [PHASE 4] Home Assistant
        (lib.mkIf config.services.home-assistant.enable [
          {
            directory = "/var/lib/hass";
            user = "hass";
            group = "hass";
          }
        ])

        # [PHASE 4] Paperless
        (lib.mkIf config.services.paperless.enable [
          {
            directory = "/var/lib/paperless";
            user = "paperless";
            group = "paperless";
          }
        ])

        # [PHASE 4] Crab-hole
        (lib.mkIf config.services.crab-hole.enable [
          {
            directory = "/var/lib/private/crab-hole";
            user = "crab-hole";
            group = "crab-hole";
          }
        ])

        # [PHASE 4] qBittorrent (config only - media is on separate dataset)
        (lib.mkIf config.services.qbittorrent.enable [
          {
            directory = "/var/lib/qBittorrent/";
            user = "qbittorrent";
            group = "qbittorrent";
          }
        ])

        # [PHASE 4] Sonarr
        (lib.mkIf config.services.sonarr.enable [
          {
            directory = "/var/lib/sonarr/.config/NzbDrone";
            user = "sonarr";
            group = "sonarr";
          }
        ])

        # [PHASE 4] Radarr
        (lib.mkIf config.services.radarr.enable [
          {
            directory = "/var/lib/radarr/.config/Radarr";
            user = "radarr";
            group = "radarr";
          }
        ])

        # [PHASE 4] Bazarr
        (lib.mkIf config.services.bazarr.enable [
          {
            directory = "/var/lib/bazarr";
            user = "bazarr";
            group = "bazarr";
          }
        ])

        # [PHASE 4] Lidarr
        (lib.mkIf config.services.lidarr.enable [
          {
            directory = "/var/lib/lidarr/.config/Lidarr";
            user = "lidarr";
            group = "lidarr";
          }
        ])

        # [PHASE 4] Jackett
        (lib.mkIf config.services.jackett.enable [
          {
            directory = "/var/lib/jackett/.config/Jackett";
            user = "jackett";
            group = "jackett";
          }
        ])

        # [PHASE 4] FlareSolverr
        (lib.mkIf config.services.flaresolverr.enable [
          {
            directory = "/var/lib/flaresolverr";
            user = "flaresolverr";
            group = "flaresolverr";
          }
        ])
      ];
    };

    # [PHASE 4 - LAST] Jellyfin media on separate dataset
    # Requires Phase 2 media dataset merge before migrating (several days of data copy)
    environment.persistence."/persist/system/jellyfin" = lib.mkIf config.services.jellyfin.enable {
      enable = true;
      hideMounts = true;
      directories = [
        {
          directory = config.services.jellyfin.media_directory;
          user = "jellyfin";
          group = "jellyfin_media";
          mode = "1770";
        }
      ];
    };

    # [PHASE 4 - LAST] qBittorrent media on separate dataset
    # Requires Phase 2 media dataset merge before migrating (several days of data copy)
    environment.persistence."/persist/system/qbittorrent" = lib.mkIf config.services.qbittorrent.enable {
      enable = true;
      hideMounts = true;
      directories = [
        {
          directory = config.services.qbittorrent.mediaDir;
          user = "qbittorrent";
          group = "qbittorrent";
          mode = "1775";
        }
      ];
    };

    # [PHASE 3] /var/log persistence - handled by storage.nix after generateBase
    environment.persistence."/persist/system/var/log" = {
      enable = true;
      hideMounts = true;
      directories = [
        "/var/log"
      ];
    };
  };
}