with builtins;

{pkgs, lib}:
let
	mkSettings = s:
		concatStringsSep
			"\n"
			(attrValues
				(mapAttrs
					(k: v:
						if typeOf v == "bool" then
							if v then "set ${k}" else "set no${k}"
						else
							"set ${k}=${toString v}")
					s
				)
			);
	boolToString = b: if b then "true" else "false";
	toLuaTable = as:
		"{" +
		( concatStringsSep
			", "
			( filter
				(attr: !isNull attr)
				( attrValues
					( mapAttrs
						(k: v: if v then "${k}=true" else null)
						as
					)
				)
			)
		) +
		"}";
	mkMapping = {
		mode,
		binding,
		command,
		nowait?false,
		silent?false,
		unique?false,
		expr?false
	}:
		"vim.api.nvim_set_keymap(${toJSON mode}, ${toJSON binding}, ${toJSON command}, ${toLuaTable {inherit nowait silent unique expr;}})";
	mkMappings =
		m:
			"lua << END-OF-KEYBINDS\n" +
			(concatStringsSep "\n" (map mkMapping m)) +
			"\nEND-OF-KEYBINDS";
	mkRuntimes = rs:
		if rs == [] then "" else
		"set runtimepath+=" +
		( concatStringsSep
			","
			(map (rt: "${rt}") rs)
		);
	mkDigraph = {keys, code}: "dig " + keys + " " + (toString code) + "\n";
	mkDigraphs = dgs: (concatStringsSep "" (map mkDigraph dgs));
	mkVimHeader = h: "\"\"\"\"\"\"\"\" ${h} \"\"\"\"\"\"\"\"\"";
	mkVimSection = section:
		(concatStringsSep "\n\n\n"
			(filter
				(v: !isNull v)
				(attrValues
					(mapAttrs
						(k: v: if "" == v then null else (mkVimHeader k) + "\n" + v)
						section
					)
				)
			)
		);
	mkVimSections = sections: concatStringsSep "\n\n\n" (map mkVimSection sections);
	mkConfig = { settings?{}, mappings?[], digraphs?[], runtimes?[], extra?"" }:
		mkVimSections [
			{"ADDITIONAL RUNTIME DIRS" = mkRuntimes runtimes;}
			{"SETTINGS" = mkSettings settings;}
			{"DIGRAPHS" = mkDigraphs digraphs;}
			{"KEY BINGINGS" = mkMappings mappings;}
			{"MANUAL SETTINGS" = extra;}
		];

	# Via https://gist.github.com/nat-418/d76586da7a5d113ab90578ed56069509
	fromGitHub = ref: repo: pkgs.vimUtils.buildVimPlugin {
		pname = "${lib.strings.sanitizeDerivationName repo}";
		version = ref;
		src = builtins.fetchGit {
			url = "https://github.com/${repo}.git";
			ref = ref;
		};
	};

in
{
	enable = true;
	plugins = with pkgs.vimPlugins; [
		vim-airline
		vim-airline-themes
		lsp_signature-nvim
		nvim-colorizer-lua
		nnn-vim
		nvim-surround
		hop-nvim
		nvim-treesitter.withAllGrammars
		nvim-ts-rainbow
		nvim-lspconfig
		true-zen-nvim
		(fromGitHub "HEAD" "whonore/Coqtail")
	];
	extraConfig = mkConfig {
		settings = {
			number = true;
			expandtab = false;
			linebreak = true;
			display = "lastline";
			comments = "s1:/*,mb:*,ex:*/,:///\\ #,:///,://!,://,b:#,:%,:XCOMM,n:>,b:-,b:*";
			tgc = true;
			tw = 90;
			foldmethod = "expr";
			foldexpr = "nvim_treesitter#foldexpr()";
			foldminlines = 10;
			foldnestmax = 2;
		};
		digraphs = [
			{ # Append
				keys = "<>";
				code = 8853;
			}
			{ # Multi Map
				keys = "-o";
				code = 8888;
			}
			{ # Degree Symbol
				keys = "'o";
				code = 176;
			}
			{ # Ring Operator
				keys = ".o";
				code = 8728;
			}
			{ # Integers
				keys = "ZZ";
				code = 8484;
			}
			{ # Naturals
				keys = "NN";
				code = 8469;
			}
			{ # Reals
				keys = "RR";
				code = 8477;
			}
			{ # Rationals
				keys = "QQ";
				code = 8474;
			}
		];
		mappings = [
			{ # New tab
				mode = "";
				binding = "<C-t>";
				command = "<Cmd>:tab split<CR>";
			}
			{ # File picker
				mode = "n";
				binding = "<C-n>";
				command = "<cmd>call nnn#pick(expand('%:p:h'))<CR>";
			}
			{ # Jump
				mode = "n";
				binding = "<C-h>";
				command = "<cmd>HopWord<CR>";
			}
			{ # Jump by characters
				mode = "n";
				binding = "<C-o>";
				command = "<cmd>HopChar2<CR>";
			}
			{ # Clear search
				mode = "";
				binding = "<C-l>";
				command = "<cmd>noh<CR>";
			}
			{
				mode = "i";
				binding = "<Tab>";
				command = "coc#pum#visible() ? coc#pum#next(1) : CheckBackspace() ? \"\\<Tab>\" : coc#refresh()";
				silent = true;
				expr = true;
			}
			{
				mode = "i";
				binding = "<S-Tab>";
				command = "coc#pum#visible() ? coc#pum#prev(1) : \"\\<C-h>\"";
				expr = true;
			}
			{
				mode = "n";
				binding = "<C-Space>";
				command = "coc#refresh()";
				silent = true;
			}
			{
				mode = "n";
				binding = "[g";
				command = "<Plug>(coc-diagnostic-prev)";
				silent = true;
			}
			{
				mode = "n";
				binding = "]g";
				command = "<Plug>(coc-diagnostic-next)";
				silent = true;
			}
			{
				mode = "n";
				binding = "gd";
				command = "<Plug>(coc-definition)";
				silent = true;
			}
			{
				mode = "n";
				binding = "gy";
				command = "<Plug>(coc-type-definition)";
				silent = true;
			}
			{
				mode = "n";
				binding = "gi";
				command = "<Plug>(coc-implementation)";
				silent = true;
			}
			{
				mode = "n";
				binding = "gr";
				command = "<Plug>(coc-references)";
				silent = true;
			}
			{
				mode = "n";
				binding = "K";
				command = ":call ShowDocumentation()<CR>";
				silent = true;
			}
			{
				mode = "n";
				binding = "...";
				command = "<Plug>(coc-codeaction-cursor)";
				silent = true;
			}
			{
				mode = "n";
				binding = "<Space>rn";
				command = "<Plug>(coc-rename)";
				silent = true;
			}
			{
				mode = "n";
				binding = "<Space>cl";
				command = "<Plug>(coc-codelens-action)";
				silent = true;
			}
		];
		runtimes = [neovim/laserwave];
		extra = builtins.readFile neovim/init.vim;
	};
	coc.enable = true;
	coc.settings = {
		"diagnostic-languageserver.filetypes" = {
			python = "mypy";
		};
		haskell = {
			command = "haskell-language-server-wrapper";
			args = ["--lsp"];
			rootPatterns = ["*.cabal" "stack.yaml" "cabal.project" "package.yaml" "hie.yaml"];
			filetypes = ["hs" "lhs" "haskell" "lhaskell"];
		};
	};
}