neovim-flake/modules/languages/rust.nix

{
  pkgs,
  config,
  lib,
  ...
}: let
  inherit (lib) isList nvim mkEnableOption mkOption types mkIf mkMerge optionalString boolToString optionals;

  cfg = config.vim.languages.rust;
in {
  options.vim.languages.rust = {
    enable = mkEnableOption "Rust language support";

    treesitter = {
      enable = mkEnableOption "Rust treesitter" // {default = config.vim.languages.enableTreesitter;};
      package = nvim.types.mkGrammarOption pkgs "rust";
    };

    crates = {
      enable = mkEnableOption "crates-nvim, tools for managing dependencies";
      codeActions = mkOption {
        description = "Enable code actions through null-ls";
        type = types.bool;
        default = true;
      };
    };

    lsp = {
      enable = mkEnableOption "Rust LSP support (rust-analyzer with extra tools)" // {default = config.vim.languages.enableLSP;};

      package = mkOption {
        description = "rust-analyzer package, or the command to run as a list of strings";
        example = ''[lib.getExe pkgs.jdt-language-server "-data" "~/.cache/jdtls/workspace"]'';
        type = with types; either package (listOf str);
        default = pkgs.rust-analyzer;
      };

      opts = mkOption {
        description = "Options to pass to rust analyzer";
        type = types.str;
        default = "";
      };
    };

    dap = {
      enable = mkOption {
        description = "Rust Debug Adapter support";
        type = types.bool;
        default = config.vim.languages.enableDAP;
      };
      package = mkOption {
        description = "lldb pacakge";
        type = types.package;
        default = pkgs.lldb;
      };
    };
  };

  config = mkIf cfg.enable (mkMerge [
    (mkIf cfg.crates.enable {
      vim.lsp.null-ls.enable = mkIf cfg.crates.codeActions true;

      vim.startPlugins = ["crates-nvim"];

      vim.autocomplete.sources = {"crates" = "[Crates]";};
      vim.luaConfigRC.rust-crates = nvim.dag.entryAnywhere ''
        require('crates').setup {
          null_ls = {
            enabled = ${boolToString cfg.crates.codeActions},
            name = "crates.nvim",
          }
        }
      '';
    })
    (mkIf cfg.treesitter.enable {
      vim.treesitter.enable = true;
      vim.treesitter.grammars = [cfg.treesitter.package];
    })
    (mkIf (cfg.lsp.enable || cfg.dap.enable) {
      vim.startPlugins = ["rust-tools"] ++ optionals cfg.dap.enable [cfg.dap.package];

      vim.lsp.lspconfig.enable = true;
      vim.lsp.lspconfig.sources.rust-lsp = ''
        local rt = require('rust-tools')
        rust_on_attach = function(client, bufnr)
          default_on_attach(client, bufnr)
          local opts = { noremap=true, silent=true, buffer = bufnr }
          vim.keymap.set("n", "<leader>ris", rt.inlay_hints.set, opts)
          vim.keymap.set("n", "<leader>riu", rt.inlay_hints.unset, opts)
          vim.keymap.set("n", "<leader>rr", rt.runnables.runnables, opts)
          vim.keymap.set("n", "<leader>rp", rt.parent_module.parent_module, opts)
          vim.keymap.set("n", "<leader>rm", rt.expand_macro.expand_macro, opts)
          vim.keymap.set("n", "<leader>rc", rt.open_cargo_toml.open_cargo_toml, opts)
          vim.keymap.set("n", "<leader>rg", function() rt.crate_graph.view_crate_graph("x11", nil) end, opts)
          ${optionalString cfg.dap.enable ''
          vim.keymap.set("n", "<leader>rd", ":RustDebuggables<cr>", opts)
          vim.keymap.set(
            "n", "${config.vim.debugger.nvim-dap.mappings.continue}",
            function()
              local dap = require("dap")
              if dap.status() == "" then
                vim.cmd "RustDebuggables"
              else
                dap.continue()
              end
            end,
            opts
          )
        ''}
        end
        local rustopts = {
          tools = {
            autoSetHints = true,
            hover_with_actions = false,
            inlay_hints = {
              only_current_line = false,
            }
          },
          server = {
            capabilities = capabilities,
            on_attach = rust_on_attach,
            cmd = ${
          if isList cfg.lsp.package
          then nvim.lua.expToLua cfg.lsp.package
          else ''{"${cfg.lsp.package}/bin/rust-analyzer"}''
        },
            settings = {
              ${cfg.lsp.opts}
            }
          },

          ${optionalString cfg.dap.enable ''
          dap = {
            adapter = {
              type = "executable",
              command = "${cfg.dap.package}/bin/lldb-vscode",
              name = "rt_lldb",
            },
          },
        ''}
        }
        rt.setup(rustopts)
      '';
    })
  ]);
}