# Defines the kakrc.

{
    # Feature flags
    typescript ? false,
    haskell ? false,
    python ? false,
    rust ? false,
    nix ? true,

    # Color theme
    theme,

	# Build tools
    pkgs,
    lib,
}:

	
let keybinds = ''
		map global insert <a-tab> <esc>:buffer-next<ret>
		map global normal <a-tab> :buffer-next<ret>
    '';

	# Initialization code for IDE mode needed for every supported
	# language, and inlay diagnostics.
    ide-init = ''
		eval %sh{ kak-lsp --kakoune -s $kak_session }
        lsp-enable-window

		lsp-inlay-diagnostics-enable window

		hook window ModeChange .*:.*:insert %{
			remove-highlighter window/lsp_diagnostics
		}

		hook window ModeChange .*:insert:normal %{
			lsp-inlay-diagnostics-enable window
		}

    '';

	# Implies `ide-init`. Adds code actions and hover.
    ide-core = ''

		${ide-init}

        map buffer normal <tab> ': lsp-code-actions<ret>'
        map buffer normal <ret> ': lsp-hover<ret>'

    '';

	# Implies `ide-core`, which implies `ide-init`.
	ide-full = ''
	
		${ide-core}

		hook window -group semtok BufReload .*  lsp-semantic-tokens
		hook window -group semtok NormalIdle .* lsp-semantic-tokens
		hook window -group semtok InsertIdle .* lsp-semantic-tokens
		
		hook -once -always window WinSetOption filetype=.* %{
			remove-hooks window semtok
		}

        map global normal <a-down>  ': lsp-next-function<ret>'
        map global normal <a-up>    ': lsp-previous-function<ret>'
        map global normal <a-left>  ': lsp-previous-location *goto*<ret>'
        map global normal <a-right> ': lsp-next-location *goto*<ret>'

	''; in


    # Nix hacking-related configuration. Nix has a very weak language
    # server, and it basically only supports `ide-init` (for completions).
let nix-config = (lib.optionalString nix ''
        hook global WinSetOption filetype=nix %{
            ${ide-init}
        }
    '');

    # Sometimes work requires me to touch the frontend. Ew. `ide-core`
    # suffices here.
	typescript-config = (lib.optionalString typescript ''
        hook global WinSetOption filetype=(javascript|typescript) %{
            ${ide-core}
        }
    '');

    # Python-related config. Python does not support more features than
    # those in `ide-core`.
    python-config = (lib.optionalString python ''
		hook global WinSetOption filetype=python %{

			${ide-core}

            face window keyword rgb:${green.bright}
            face window meta keyword
            
		}
    '');

    # Haskell development. Haskell has a language server with
    # the features in `ide-full`.
    haskell-config = (lib.optionalString haskell ''
		hook global WinSetOption filetype=haskell %{

			${ide-full}
			
			set-option buffer tabstop 2

            face global variable  rgb:${purple.normal}
            face global attribute keyword
            face global operator  keyword
            face global keyword   rgb:${blue.bright}
            face global value     string
            face global meta      rgb:${pink.normal}

		}
    '');

    # Rust development. Rust's language servers all support the
    # `ide-full` features.
    rust-config = (lib.optionalString rust ''
		hook global WinSetOption filetype=rust %{

			${ide-full}

			hook global -group yeet ModuleLoaded rust %{

				# Override the Rust highlighting with semantic
				# tokens supplied by the LSP client
    			remove-hooks global rust-highlight
    			remove-highlighter shared/rust

    			# Request tokens
				lsp-semantic-tokens
				
				# Self-destruct this hook (it should only run once)
				remove-hooks global yeet

			}

		}
    '');

in pkgs.writeTextFile (rec {
	name = "kakrc.kak";
    destination = "/share/kak/autoload/${name}";
    text = with theme; ''

		add-highlighter global/ number-lines -separator ' │ ' -hlcursor

		set global tabstop 4

		face global InlayHint				rgb:828282
		face global InlayDiagnosticWarning 	rgb:a39e31+f
		face global InlayDiagnosticError	rgb:ad494f+f
		face global InlayDiagnosticHint		rgb:4d965a+f
		face global InlayDiagnosticInfo		rgb:4d965a+f

    '' ++ keybinds
       ++ typescript-config
       ++ haskell-config
       ++ python-config
       ++ rust-config
       ++ nix-config;
})