# Derivation for Emacs configured with the packages that I need:
{ pkgs }:

let emacsWithPackages = with pkgs; (emacsPackagesNgGen emacs).emacsWithPackages;
sly = with pkgs; emacsPackagesNg.melpaBuild {
  pname   = "sly";
  version = "20180221.1414";

  src = fetchFromGitHub {
    owner  = "joaotavora";
    repo   = "sly";
    rev    = "486bfbe95612bcdc0960c490207970a188e0fbb9";
    sha256 = "0ib4q4k3h3qn88pymyjjmlmnpizdn1mfg5gpk5a715nqsgxlg09l";
  };

  recipeFile = fetchurl {
    url    = "https://raw.githubusercontent.com/melpa/melpa/23b9e64887a290fca7c7ab2718f627f8d728575f/recipes/sly";
    sha256 = "1pmyqjk8fdlzwvrlx8h6fq0savksfny78fhmr8r7b07pi20y6n9l";
    name   = "sly";
  };
};

# Building sly-company requires quite some dancing because
# company-mode is required at build time.
trivialBuildWithCompany = with pkgs; callPackage <nixos/pkgs/build-support/emacs/trivial.nix> {
  emacs = with pkgs; emacsWithPackages(epkgs: [ epkgs.elpaPackages.company ]);
};

sly-company = with pkgs; trivialBuildWithCompany {
  pname   = "sly-company";
  version = "master";

  src = fetchFromGitHub {
    owner  = "joaotavora";
    repo   = "sly-company";
    rev    = "dfe18218e4b2ee9874394b50f82f5172f41c462c";
    sha256 = "1bj8w2wfq944cnhsk5xx41mfrjv89scrg4w98kqgda5drkpdf8a7";
  };
};

# The nix-mode in the official repositories is old and annoying to
# work with, pin it to something newer instead:
nix-mode = with pkgs; emacsPackagesNg.melpaBuild {
  pname   = "nix-mode";
  version = "20180306";

  src = fetchFromGitHub {
    owner  = "NixOS";
    repo   = "nix-mode";
    rev    = "0ac0271f6c8acdbfddfdbb1211a1972ae562ec17";
    sha256 = "157vy4xkvaqd76km47sh41wykbjmfrzvg40jxgppnalq9pjxfinp";
  };

  recipeFile = writeText "nix-mode-recipe" ''
    (nix-mode :repo "NixOS/nix-mode" :fetcher github
              :files (:defaults (:exclude "nix-mode-mmm.el")))
  '';
};

# The default Rust language server mode is not really usable, install
# `eglot` instead and hope for the best.
eglot = with pkgs; emacsPackagesNg.melpaBuild rec {
  pname = "eglot";
  version = "0.8";

  src = fetchFromGitHub {
    owner  = "joaotavora";
    repo   = "eglot";
    rev    = version;
    sha256 = "1avsry84sp3s2vr2iz9dphm579xgw8pqlwffl75gn5akykgazwdx";
  };
};

# prescient & prescient-ivy provide better filtering in ivy/counsel
prescient = with pkgs; emacsPackagesNg.melpaBuild {
  pname = "prescient";
  version = "20180611";

  src = fetchFromGitHub {
    owner  = "raxod502";
    repo   = "prescient.el";
    rev    = "19a2c6b392ca6130dbbcf70cba57ee34d64fe50c";
    sha256 = "136q785lyhpgyaiysyq4pw11l83sa9h3q57v6papx813gf7rb7v7";
  };

  recipeFile = writeText "prescient-recipe" ''
    (prescient :files ("prescient.el" "ivy-prescient.el"))
  '';
};

in emacsWithPackages(epkgs:
  # Pinned packages (from unstable):
  (with pkgs; with lib; attrValues pinnedEmacs) ++

  # Actual ELPA packages (the enlightened!)
  (with epkgs.elpaPackages; [
    ace-window
    adjust-parens
    avy
    company
    pinentry
    rainbow-mode
    undo-tree
    which-key
  ]) ++

  # MELPA packages:
  (with epkgs.melpaPackages; [
    browse-kill-ring
    cargo
    dash
    dash-functional
    dockerfile-mode
    edit-server
    elm-mode
    erlang
    flx
    go-mode
    gruber-darker-theme
    haskell-mode
    ht
    idle-highlight-mode
    jq-mode
    kotlin-mode
    magit
    multi-term
    multiple-cursors
    nginx-mode
    paredit
    password-store
    pg
    racket-mode
    rainbow-delimiters
    restclient
    rust-mode
    s
    smartparens
    string-edit
    terraform-mode
    telephone-line
    toml-mode
    uuidgen
    web-mode
    websocket
    yaml-mode
  ]) ++

  # Custom packaged Emacs packages:
  [ sly sly-company nix-mode eglot prescient pkgs.notmuch ]
)