{ config, lib, ... }:

with lib;

let
  cfg = config.numbus.hardware.disks.boot;

  bootCount = builtins.length cfg.list;

  singleDiskConfig = {
    disko.devices.disk.main = {
      type = "disk";
      device = head cfg.list;
      content = {
        type = cfg.partitionTableScheme;
        partitions = {
          ESP = {
            size = cfg.partition.boot.size;
            type = cfg.partition.boot.esp;
            content = {
              type = "filesystem";
              format = cfg.partition.boot.filesystem;
              mountpoint = "/boot";
              mountOptions = [ "umask=0077" ];
            };
          };
          swap = {
            size = cfg.partition.swap.size;
            content = {
              type = "swap";
              randomEncryption = cfg.partition.swap.encrypt;
            };
          };
          luks = {
            size = cfg.partition.root.size;
            content = {
              type = "luks";
              name = "boot";
              settings.keyFile = "/run/secrets/disks/boot";
              content = {
                type = "filesystem";
                format = cfg.partition.root.filesystem;
                mountpoint = "/";
              };
            };
          };
        };
      };
    };
  };

  raid1DiskConfig = {
    disko.devices.disk = lib.listToAttrs (lib.imap0 (i: device: {
      name = "boot-${toString i}";
      value = {
        type = "disk";
        inherit device;
        content = {
          type = cfg.partitionTableScheme;
          partitions = {
            ESP = { size = cfg.partition.boot.size; type = cfg.partition.boot.esp; content = { type = "mdraid"; name = "boot"; }; };
            swap = { size = cfg.partition.swap.size; content = { type = "mdraid"; name = "swap"; }; };
            mdadm = { size = cfg.partition.root.size; content = { type = "mdraid"; name = "raid1"; }; };
          };
        };
      };
    }) cfg.list);

    disko.devices.mdadm = {
      boot = {
        type = "mdadm";
        level = 1;
        metadata = "1.0";
        content = {
          type = "filesystem";
          format = cfg.partition.boot.filesystem;
          mountpoint = "/boot";
          mountOptions = [ "umask=0077" ];
        };
      };
      swap = {
        type = "mdadm";
        level = 1;
        content = {
          type = "swap";
          randomEncryption = cfg.partition.swap.encrypt;
        };
      };
      raid1 = {
        type = "mdadm";
        level = 1;
        content = {
          type = "luks";
          name = "boot";
          settings.keyFile = "/run/secrets/disks/boot";
          content = {
            type = "filesystem";
            format = cfg.partition.root.filesystem;
            mountpoint = "/";
          };
        };
      };
    };
  };
in

{
  options.numbus.hardware.disks = {
    boot = {
      list = mkOption {
        type = types.listOf types.str;
        example = [ "/dev/disk/by-id/nvme_SAMSUNG_MZVPYEHCO_159Ejz224G0000" "/dev/disk/by-id/ata-San_Disk_159Ejz224G" ];
        description = "A set of by-id path of disk(s) that will be used as boot disk(s). At least one disk must be set.";
      };
      partitionTableScheme = mkOption {
        type = types.enum [ "gpt" "mbr" ];
        default = "gpt";
        example = "gpt";
        description = "The scheme of the partition table. Use \"gpt\" for modern devices and \"mbr\" for legacy ones.";
      };
      partition = {
        root = {
          filesystem = mkOption {
            type = types.enum [ "ext4" "btrfs" "xfs" ];
            default = "ext4";
            example = "ext4";
            description = "The filesystem to use for the root partition of the boot disk(s).";
          };
          size = mkOption {
            type = types.str;
            default = "100%";
            example = "100%";
            description = "The size of the root partition. Use G for GBs and M for MBs.";
          };
        };
        boot = {
          filesystem = mkOption {
            type = types.enum [ "vfat" ];
            default = "vfat";
            example = "vfat";
            description = "The filesystem to use for the boot partition of the boot disk(s).";
          };
          esp = mkOption {
            type = types.enum [ "EF00" "EF02" ];
            default = "EF00";
            example = "EF00";
            description = "The ESP type to use for the boot partition. Use EF02 for UEFI and EF00 for BIOS.";
          };
          size = mkOption {
            type = types.str;
            default = "1G";
            example = "1G";
            description = "The size of the boot partition.";
          };
        };
        swap = {
          enable = mkOption {
            type = types.bool;
            default = true;
            example = true;
            description = "Wether to create a swap partition. Useful for servers that don't have a lot of RAM.";
          };
          encrypt = mkOption {
            type = types.bool;
            default = true;
            example = true;
            description = "Wether to encrypt randomly the swap partition. Disable if you need hibernation";
          };
          size = mkOption {
            type = types.str;
            default = "16G";
            example = "16G";
            description = "Size of the swap partition. Use G for GBs and M for MBs.";
          };
        };
      };
    };
  };

  config = mkMerge [
    {
      sops.secrets."disks/boot" = {
        sopsFile = "/etc/nixos/secrets/disks/boot.yaml";
        gid = "0";
        uid = "0";
        mode = "0400";
      };
    }
    (mkIf (bootCount == 1) singleDiskConfig)
    (mkIf (bootCount == 2) raid1DiskConfig)
  ];
}