Vim: Windows-style copy paste search replace

" Windows common keyboard shortcuts and pasting behavior {{{

" Recommended vimrc settings:
"     Set clipboard like this:
"         NOTE: Use ^= to prepend a value to a comma-separated list. See :h set^=
"         set clipboard^=unnamedplus            " Works on Linux but has issues yanking on Windows.
"         set clipboard^=unnamed,unnamedplus    " Works on Linux and Windows (and probably MacVim which needed the unnamed option the last time i used it).
"
"     Set mouse like this:
"         set mouse=a    " Ensures mouse binds work in all modes.
"
"     Disable autoselect:
"         NOTE: This forces MiddleMouse clicks in other programs to paste the contents of Vim's "+ unnamedplus register instead of the "* unnamed selection register. See :h go-a
"         set guioptions-=a
"         set guioptions-=A
"
" NOTE: On Linux you need to keep the source-window of a copy-operation open for a paste to occur inside another window.

" Functions {{{

" Uncomment to enable debugging.
" Check debug output with :messages
" let s:debug_smart_cut = 1
" let s:debug_smart_copy = 1
" let s:debug_smart_paste = 1

function! SmartCut() " {{{
    if !has('clipboard')
        echoerr 'Clipboard support is required to use this function.'
        return
    endif

    let clipboard_register = '+'

    " Restore the visual selection with 'gv' and delete the selection into the clipboard.
    " NOTE: 'd' (delete) is better than 'c' (copy) because it moves the caret to the right for us.
    execute 'normal! gv"' . clipboard_register . 'd'

    " Enter insert mode.
    startinsert

    " Gets the value if it exists, else returns 0.
    if get(s:, 'debug_smart_cut')
        echomsg "SmartCut"
        echomsg "    clipboard contents: " . getreg(clipboard_register)
    endif
endfunction " }}}

function! SmartCopy() " {{{
    if !has('clipboard')
        echoerr 'Clipboard support is required to use this function.'
        return
    endif

    let clipboard_register = '+'

    " Restore the visual selection with 'gv' and yank the selection into the clipboard.
    execute 'normal! gv"' . clipboard_register . 'y'

    " Gets the value if it exists, else returns 0.
    if get(s:, 'debug_smart_copy')
        echomsg "SmartCopy"
        echomsg "    clipboard contents: " . getreg(clipboard_register)
    endif
endfunction " }}}

function! SmartPaste() " {{{
    if !has('clipboard')
        echoerr 'Clipboard support is required to use this function.'
        return
    endif

    if !&modifiable
        return
    endif

    " See :help '> for more information. Hint: if you select some text and press ':' you will see :'<,'>
    " SOURCE: http://superuser.com/questions/723621/how-can-i-check-if-the-cursor-is-at-the-end-of-a-line
    " SOURCE: http://stackoverflow.com/questions/7262536/vim-count-lines-in-selected-range
    " SOURCE: https://git.zug.fr/config/vim/blob/master/init.vim
    " SOURCE: https://git.zug.fr/config/vim/blob/master/after/plugin/zzzmappings.vim
    let currentColumn = col(".")
    let currentLine = line(".")
    let lastVisibleLetterColumn = col("$") - 1
    let lastLineOfBuffer = line("$")
    let selectionEndLine = line("'>")
    let selectionEndLineLength = strchars(getline(selectionEndLine))
    let nextLineLength = strchars(getline(currentLine + 1))
    let selectionStartColumn = col("'<")
    let selectionEndColumn = col("'>")

    " If selection does not include or go beyond the last visible character of the line (by also selecting the invisible EOL character).
    if selectionEndColumn < selectionEndLineLength
        let pee = 'P'

        " Gets the value if it exists, else returns 0.
        if get(s:, 'debug_smart_paste')
            echomsg "SmartPaste special case #1"
        endif

    " If attempting to paste on a blank last line.
    elseif selectionEndLineLength == 0 && selectionEndLine == lastLineOfBuffer
        let pee = 'P'

        " Gets the value if it exists, else returns 0.
        if get(s:, 'debug_smart_paste')
            echomsg "SmartPaste special case #2"
        endif

    " If selection ends after the last visible character of the line (by also selecting the invisible EOL character),
    " or the line is visually selected (Shift + V),
    " and the next line is not blank,
    " and selection does not end on the last line.
    elseif selectionEndColumn > selectionEndLineLength && nextLineLength > 0 && selectionEndLine != lastLineOfBuffer
        let pee = 'P'

        " Gets the value if it exists, else returns 0.
        if get(s:, 'debug_smart_paste')
            echomsg "SmartPaste special case #3"
        endif

    else
        let pee = 'p'

        " Gets the value if it exists, else returns 0.
        if get(s:, 'debug_smart_paste')
            echomsg "SmartPaste default case"
        endif
    endif

    let clipboard_register = '+'

    " Gets the value if it exists, else returns 0.
    if get(s:, 'debug_smart_paste')
        echomsg "SmartPaste"
        echomsg "    clipboard contents: " . getreg(clipboard_register)
        echomsg "    currentColumn: " . currentColumn
        echomsg "    currentLine: " . currentLine
        echomsg "    lastVisibleLetterColumn: " . lastVisibleLetterColumn
        echomsg "    lastLineOfBuffer: " . lastLineOfBuffer
        echomsg "    selectionEndLine: " . selectionEndLine
        echomsg "    selectionEndLineLength: " . selectionEndLineLength
        echomsg "    nextLineLength: " . nextLineLength
        echomsg "    selectionStartColumn: " . selectionStartColumn
        echomsg "    selectionEndColumn: " . selectionEndColumn
        echomsg "    pee: " . pee
        echomsg "    selection bounds" . string([getpos("'<")[1:2], getpos("'>")[1:2]])
        echomsg "    visualmode(): " . visualmode()
        echomsg "    mode(): " . mode()
        echomsg "    getpos('.'): " . string(getpos('.'))
    endif

    try
        " Enter paste mode.
        " NOTE: This prevents InsertCharPre autocommands from running repeatedly for each character in the pasted string.
        set paste

        " Backup clipboard.
        let clipboard_contents = getreg(clipboard_register)
        let clipboard_type = getregtype(clipboard_register)

        " If clipboard type is linewise.
        if clipboard_type[0] == 'V'
            " Change clipboard register to characterwise mode.
            call setreg(clipboard_register, clipboard_contents, 'v')
        endif

        " Restore the visual selection with 'gv' and paste the clipboard contents there.
        execute 'normal! gv"' . clipboard_register . pee

        " Restore clipboard.
        call setreg(clipboard_register, clipboard_contents, clipboard_type)
    catch /E353:\ Nothing\ in\ register/
    finally
        " Exit paste mode.
        set nopaste
    endtry
endfunction " }}}

function! SmartFind(...) " {{{
    let l:mode = get(a:000, 0, mode())
    if s:IsNormalMode(l:mode)
        let wordUnderCursor = expand('<cword>')
        if wordUnderCursor == ''
            execute 'promptfind'
        else
            execute 'promptfind' wordUnderCursor
        endif
    else
        let [line_start, column_start] = getpos("'<")[1:2]
        let [line_end, column_end] = getpos("'>")[1:2]
        " TODO: added this but idk if its bad to do because function doesn't strip :'<,'> for certain modes.
        if (line2byte(line_start) + column_start) > (line2byte(line_end) + column_end)
            let [line_start, column_start, line_end, column_end] = [line_end, column_end, line_start, column_start]
        endif
        let lines = getline(line_start, line_end)
        if empty(lines)
            execute 'promptfind'
            return
        endif
        let lines[-1] = lines[-1][: column_end - (&selection ==# 'inclusive' ? 1 : 2)]
        let lines[0] = lines[0][column_start - 1:]
        execute 'promptfind' lines[0]
    endif
endfunction " }}}

function! SmartReplace(...) " {{{
    let l:mode = get(a:000, 0, mode())
    if s:IsNormalMode(l:mode)
        let wordUnderCursor = expand('<cword>')
        if wordUnderCursor == ''
            execute 'promptrepl'
        else
            execute 'promptrepl' wordUnderCursor
        endif
    else
        let [line_start, column_start] = getpos("'<")[1:2]
        let [line_end, column_end] = getpos("'>")[1:2]
        " TODO: added this but idk if its bad to do because function doesn't strip :'<,'> for certain modes.
        if (line2byte(line_start) + column_start) > (line2byte(line_end) + column_end)
            let [line_start, column_start, line_end, column_end] = [line_end, column_end, line_start, column_start]
        endif
        let lines = getline(line_start, line_end)
        if empty(lines)
            execute 'promptrepl'
            return
        endif
        let lines[-1] = lines[-1][: column_end - (&selection ==# 'inclusive' ? 1 : 2)]
        let lines[0] = lines[0][column_start - 1:]
        execute 'promptrepl' lines[0]
    endif
endfunction " }}}

function! SmartSaveFile() " {{{
    " SOURCE: http://vim.wikia.com/wiki/Map_Ctrl-S_to_save_current_or_new_files

    " If file is saved.
    if !&modified
        return
    endif

    try
        " If the current buffer has no name.
        if empty(bufname('%'))
            " Display a save dialog so the user can specify a file name.
            browse confirm write
        else
            " Force a write even if a file exists with that name.
            confirm write
        endif
    catch /E212:\ Can't\ open\ file\ for\ writing/
        if has("win32") || has("win64")
            echomsg "ERROR: You lack write permission for this directory or the file name is not valid."
        else
            " NOTE: The [browse confirm write] call above will establish the filename in the case of an empty buffer.
            " NOTE: Try-catch needed because [redraw!] may erase an error message.
            try
                " A hack that uses tee to output the buffer to the % filename with sudo permissions.
                " SOURCE: https://stackoverflow.com/questions/2600783/how-does-the-vim-write-with-sudo-trick-work
                execute("w !sudo tee %")

                if v:shell_error
                    throw 'Failed to save file.'
                else
                    " Reload the file, otherwise vim will detect the file changed and ask you for permission to reload the file.
                    silent edit!

                    " Clears the command-line and removes 'Press ENTER or type command to continue' prompt.
                    " SOURCE: https://vim.fandom.com/wiki/Avoiding_the_%22Hit_ENTER_to_continue%22_prompts
                    redraw!
                endif
            catch /.*/
                echoerr 'SmartSaveFile() Unhandled Exception: ' . v:exception
            endtry
        endif
    endtry
endfunction " }}}

function! SmartCopyMessageHistory() " {{{
    redir @+
    silent execute(':messages')
    redir END
endfunction " }}}

" }}} Functions

" Binds {{{

" Paste for MiddleMouse in terminal, normal, visual, and insert mode {{{

tnoremap <MiddleMouse> <C-w>"+

" NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
nnoremap <silent> <MiddleMouse> <C-v>:<C-u>call SmartPaste()<CR>

" NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
vnoremap <silent> <MiddleMouse> :<C-u>call SmartPaste()<CR>

" Characterwise paste for insert mode.
" SOURCE: https://vim.fandom.com/wiki/Pasting_registers
" NOTE: <C-o> executes a normal-mode command without leaving insert mode. See :help ins-special-special
" NOTE: <C-r>+ inserts the contents of the unnamedplus register during insert mode. See :h i_CTRL-R
" NOTE: <C-r>+ doesn't work for Ctrl-v yanked and pasted columns of text. It forces characterwise selections to be linewise pasted. <C-r><C-o>+ works though.
" [bad, triggers InsertCharPre for each pasted letter] inoremap <MiddleMouse> <C-r><C-r>+
" [works] inoremap <MiddleMouse> <C-o>"+<MiddleMouse>
" [works, but no need for paste mode i think because it doesn't trigger InsertCharPre events for each pasted letter] inoremap <MiddleMouse> <C-o>:set paste<CR><C-r><C-o>+<C-o>:set nopaste<CR>
inoremap <MiddleMouse> <C-r><C-o>+

" Disable weird multi-click things you can do with middle mouse button.
" SOURCE: http://vim.wikia.com/wiki/Mouse_wheel_for_scroll_only_-_disable_middle_button_paste
tnoremap <2-MiddleMouse> <Nop>
nnoremap <2-MiddleMouse> <Nop>
inoremap <2-MiddleMouse> <Nop>
vnoremap <2-MiddleMouse> <Nop>
tnoremap <3-MiddleMouse> <Nop>
nnoremap <3-MiddleMouse> <Nop>
inoremap <3-MiddleMouse> <Nop>
vnoremap <3-MiddleMouse> <Nop>
tnoremap <4-MiddleMouse> <Nop>
nnoremap <4-MiddleMouse> <Nop>
inoremap <4-MiddleMouse> <Nop>
vnoremap <4-MiddleMouse> <Nop>

" }}} Paste for MiddleMouse in terminal, normal, visual, and insert mode

" If OS is not mac.
if system('uname') !~ 'Darwin' " NOTE: MacVim provides Command+C|X|V|A|S and undo/redo functionality and also can Command+C|V to the command-line by default.
    " Paste functionality for terminal mode {{{

    tnoremap <C-v> <C-w>"+

    " }}} Paste functionality for terminal mode

    " Copy, paste, and select-all functionality for command-line {{{

    " SOURCE: https://opensource.apple.com/source/vim/vim-62.41.2/runtime/macmap.vim.auto.html
    " NOTE: Only copy and paste are possible in the command-line from what i can tell.
    "       Their is no undo for text typed in the command-line and you cannot paste text onto a selection of text to replace it.
    cnoremap <C-c> <C-y>
    cnoremap <C-v> <C-r>+

    " Everyone seems to bind this. No way to select-all, but we can move the caret all the way to the left of the command-line. Yay.
    cnoremap <C-A> <Home>

    " Copy message history to the clipboard.
    " NOTE: This is a workaround for not being able to select all.
    nnoremap <silent> <Leader>mh :<C-u>call SmartCopyMessageHistory()<CR>

    " }}} Copy, paste, select-all functionality for command-line

    " Cut, copy, paste functionality for visual and insert mode {{{

    " Cut, copy, and paste functionality for visual mode.
    " SOURCE: http://superuser.com/questions/10588/how-to-make-cut-copy-paste-in-gvim-on-ubuntu-work-with-ctrlx-ctrlc-ctrlv
    " NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
    vnoremap <silent> <C-x> :<C-u>call SmartCut()<CR>
    vnoremap <silent> <C-c> :<C-u>call SmartCopy()<CR>
    vnoremap <silent> <C-v> :<C-u>call SmartPaste()<CR>

    " Characterwise paste for insert mode.
    " SOURCE: https://vim.fandom.com/wiki/Pasting_registers
    " NOTE: <C-o> executes a normal-mode command without leaving insert mode. See :help ins-special-special
    " NOTE: <C-r>+ inserts the contents of the unnamedplus register during insert mode. See :h i_CTRL-R
    " NOTE: <C-r>+ doesn't work for Ctrl-v yanked and pasted columns of text. It forces characterwise selections to be linewise pasted. <C-r><C-o>+ works though.
    " [works, but no need for paste mode i think because it doesn't trigger InsertCharPre events for each pasted letter] inoremap <C-v> <C-o>:set paste<CR><C-r><C-o>+<C-o>:set nopaste<CR>
    inoremap <C-v> <C-r><C-o>+

    " }}} Cut, copy, paste functionality for visual and insert mode

    " Select-all functionality for normal, visual, and insert mode {{{

    " SOURCE: http://vim.wikia.com/wiki/Using_standard_editor_shortcuts_in_Vim
    nnoremap <C-a> ggVG
    " <ESC> needed to prevent the existing characterwise selection from getting converted into a linewise selection (all the way home for the current line).
    vnoremap <C-a> <Esc>ggVG
    inoremap <C-a> <Esc>ggVG

    " }}} Select-all functionality for normal, visual, and insert mode

    " Save functionality for normal, visual, and insert mode {{{

    nnoremap <silent> <C-s> :call SmartSaveFile()<CR>

    " NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
    vnoremap <silent> <C-s> :<C-u>call SmartSaveFile()<CR>gv

    " NOTE: <C-o> executes a normal-mode command without leaving insert mode. See :help ins-special-special
    inoremap <silent> <C-s> <C-o>:call SmartSaveFile()<CR>

    " }}} Save functionality for normal, visual, and insert mode

    " Undo and redo functionality for normal, visual, and insert mode {{{

    nnoremap <C-z> <Esc>u
    nnoremap <C-y> <Esc><C-r>

    " NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
    vnoremap <C-z> :<C-u>uV
    vnoremap <C-y> :<C-u><C-r>V

    inoremap <C-z> <Esc>uI
    inoremap <C-y> <Esc><C-r>I

    " Disable Vim normal-mode undo/redo keys.
    " Having a single key for undo is an accident waiting to happen, especially when 'u' and 'U' are also used as visual-mode character case toggles.
    " SOURCE: https://stackoverflow.com/questions/57714401/vi-vim-remap-or-unmap-built-in-command-the-u-key-in-visual-mode
    nnoremap u <NOP>
    nnoremap <C-r> <NOP>

    " }}} Undo and redo functionality for normal, visual, and insert mode

    " Find and Replace functionality for normal, visual, and insert mode {{{

    nnoremap <silent> <C-f> :call SmartFind('n')<CR>
    nnoremap <silent> <C-h> :call SmartReplace('n')<CR>

    " NOTE: <C-u> removes the '<,'> visual-selection from the command-line. See :h c_CTRL-u
    vnoremap <silent> <C-f> :<C-u>call SmartFind('v')<CR>
    vnoremap <silent> <C-h> :<C-u>call SmartReplace('v')<CR>

    " NOTE: <C-o> executes a normal-mode command without leaving insert mode. See :help ins-special-special
    inoremap <silent> <C-f> <C-o>:call SmartFind('i')<CR>
    inoremap <silent> <C-h> <C-o>:call SmartReplace('i')<CR>

    " }}} Find and Replace functionality for normal, visual, and insert mode
endif

" }}} Binds

" }}} Windows common keyboard shortcuts and pasting behavior