-- old coc.nvim config (minimal) 
-- vim.cmd [[
-- function! CheckBackspace() abort
--   let col = col('.') - 1
--   return !col || getline('.')[col - 1]  =~# '\s'
-- endfunction
-- 
-- inoremap <silent><expr> <TAB>
--       \ coc#pum#visible() ? coc#pum#next(1) :
--       \ CheckBackspace() ? "\<Tab>" :
--       \ coc#refresh()
-- inoremap <expr><S-TAB> coc#pum#visible() ? coc#pum#prev(1) : "\<C-h>"
-- ]]

-- some servers have issues with backup files, see #649
vim.opt.backup = false
vim.opt.writebackup = false

-- having longer updatetime (default is 4000 ms = 4s) leads to noticeable
-- delays and poor user experience
vim.opt.updatetime = 300

-- always show the signcolumn, otherwise it would shift the text each time
-- diagnostics appeared/became resolved
vim.opt.signcolumn = "yes"

local keyset = vim.keymap.set
-- autocomplete
function _G.check_back_space()
    local col = vim.fn.col('.') - 1
    return col == 0 or vim.fn.getline('.'):sub(col, col):match('%s') ~= nil
end

-- use tab for trigger completion with characters ahead and navigate
-- note: there's always a completion item selected by default, you may want to enable
-- no select by setting `"suggest.noselect": true` in your configuration file
-- note: use command ':verbose imap <tab>' to make sure tab is not mapped by
-- other plugins before putting this into your config
local opts = {silent = true, noremap = true, expr = true, replace_keycodes = false}
keyset("i", "<TAB>", 'coc#pum#visible() ? coc#pum#next(1) : v:lua.check_back_space() ? "<TAB>" : coc#refresh()', opts)
keyset("i", "<S-TAB>", [[coc#pum#visible() ? coc#pum#prev(1) : "\<C-h>"]], opts)

-- make <cr> to accept selected completion item or notify coc.nvim to format
-- <c-g>u breaks current undo, please make your own choice
keyset("i", "<cr>", [[coc#pum#visible() ? coc#pum#confirm() : "\<C-g>u\<CR>\<c-r>=coc#on_enter()\<CR>"]], opts)

-- use <c-j> to trigger snippets
keyset("i", "<c-j>", "<Plug>(coc-snippets-expand-jump)")
-- use <c-space> to trigger completion
keyset("i", "<c-space>", "coc#refresh()", {silent = true, expr = true})

-- use `[g` and `]g` to navigate diagnostics
-- use `:cocdiagnostics` to get all diagnostics of current buffer in location list
keyset("n", "[g", "<Plug>(coc-diagnostic-prev)", {silent = true})
keyset("n", "]g", "<Plug>(coc-diagnostic-next)", {silent = true})

-- goto code navigation
keyset("n", "gd", "<Plug>(coc-definition)", {silent = true})
keyset("n", "gy", "<Plug>(coc-type-definition)", {silent = true})
keyset("n", "gi", "<Plug>(coc-implementation)", {silent = true})
keyset("n", "gr", "<Plug>(coc-references)", {silent = true})

-- use k to show documentation in preview window
function _G.show_docs()
    local cw = vim.fn.expand('<cword>')
    if vim.fn.index({'vim', 'help'}, vim.bo.filetype) >= 0 then
        vim.api.nvim_command('h ' .. cw)
    elseif vim.api.nvim_eval('coc#rpc#ready()') then
        vim.fn.CocActionAsync('doHover')
    else
        vim.api.nvim_command('!' .. vim.o.keywordprg .. ' ' .. cw)
    end
end
keyset("n", "K", '<CMD>lua _G.show_docs()<CR>', {silent = true})

-- highlight the symbol and its references on a cursorhold event(cursor is idle)
vim.api.nvim_create_augroup("CocGroup", {})
vim.api.nvim_create_autocmd("CursorHold", {
    group = "CocGroup",
    command = "silent call CocActionAsync('highlight')",
    desc = "Highlight symbol under cursor on CursorHold"
})

-- symbol renaming
keyset("n", "<leader>rn", "<Plug>(coc-rename)", {silent = true})

-- formatting selected code
keyset("x", "<leader>f", "<Plug>(coc-format-selected)", {silent = true})
keyset("n", "<leader>f", "<Plug>(coc-format-selected)", {silent = true})

-- setup formatexpr specified filetype(s)
vim.api.nvim_create_autocmd("FileType", {
    group = "CocGroup",
    pattern = "typescript,json",
    command = "setl formatexpr=CocAction('formatSelected')",
    desc = "Setup formatexpr specified filetype(s)."
})

-- update signature help on jump placeholder
vim.api.nvim_create_autocmd("User", {
    group = "CocGroup",
    pattern = "CocJumpPlaceholder",
    command = "call CocActionAsync('showSignatureHelp')",
    desc = "Update signature help on jump placeholder"
})

-- apply codeaction to the selected region
-- example: `<leader>aap` for current paragraph
local opts = {silent = true, nowait = true}
keyset("x", "<leader>a", "<Plug>(coc-codeaction-selected)", opts)
keyset("n", "<leader>a", "<Plug>(coc-codeaction-selected)", opts)

-- remap keys for apply code actions at the cursor position.
keyset("n", "<leader>ac", "<Plug>(coc-codeaction-cursor)", opts)
-- remap keys for apply source code actions for current file.
keyset("n", "<leader>as", "<Plug>(coc-codeaction-source)", opts)
-- apply the most preferred quickfix action on the current line.
keyset("n", "<leader>qf", "<Plug>(coc-fix-current)", opts)

-- remap keys for apply refactor code actions.
keyset("n", "<leader>re", "<Plug>(coc-codeaction-refactor)", { silent = true })
keyset("x", "<leader>r", "<Plug>(coc-codeaction-refactor-selected)", { silent = true })
keyset("n", "<leader>r", "<Plug>(coc-codeaction-refactor-selected)", { silent = true })

-- run the code lens actions on the current line
keyset("n", "<leader>cl", "<Plug>(coc-codelens-action)", opts)


-- map function and class text objects
-- note: requires 'textdocument.documentsymbol' support from the language server
keyset("x", "if", "<Plug>(coc-funcobj-i)", opts)
keyset("o", "if", "<Plug>(coc-funcobj-i)", opts)
keyset("x", "af", "<Plug>(coc-funcobj-a)", opts)
keyset("o", "af", "<Plug>(coc-funcobj-a)", opts)
keyset("x", "ic", "<Plug>(coc-classobj-i)", opts)
keyset("o", "ic", "<Plug>(coc-classobj-i)", opts)
keyset("x", "ac", "<Plug>(coc-classobj-a)", opts)
keyset("o", "ac", "<Plug>(coc-classobj-a)", opts)


-- remap <c-f> and <c-b> to scroll float windows/popups
---@diagnostic disable-next-line: redefined-local
local opts = {silent = true, nowait = true, expr = true}
keyset("n", "<C-f>", 'coc#float#has_scroll() ? coc#float#scroll(1) : "<C-f>"', opts)
keyset("n", "<C-b>", 'coc#float#has_scroll() ? coc#float#scroll(0) : "<C-b>"', opts)
keyset("i", "<C-f>",
       'coc#float#has_scroll() ? "<c-r>=coc#float#scroll(1)<cr>" : "<Right>"', opts)
keyset("i", "<C-b>",
       'coc#float#has_scroll() ? "<c-r>=coc#float#scroll(0)<cr>" : "<Left>"', opts)
keyset("v", "<C-f>", 'coc#float#has_scroll() ? coc#float#scroll(1) : "<C-f>"', opts)
keyset("v", "<C-b>", 'coc#float#has_scroll() ? coc#float#scroll(0) : "<C-b>"', opts)

-- use ctrl-s for selections ranges
-- requires 'textdocument/selectionrange' support of language server
keyset("n", "<C-s>", "<Plug>(coc-range-select)", {silent = true})
keyset("x", "<C-s>", "<Plug>(coc-range-select)", {silent = true})

-- add `:format` command to format current buffer
vim.api.nvim_create_user_command("Format", "call CocAction('format')", {})

-- " add `:fold` command to fold current buffer
vim.api.nvim_create_user_command("Fold", "call CocAction('fold', <f-args>)", {nargs = '?'})

-- add `:or` command for organize imports of the current buffer
vim.api.nvim_create_user_command("OR", "call CocActionAsync('runCommand', 'editor.action.organizeImport')", {})

-- add (neo)vim's native statusline support
-- note: please see `:h coc-status` for integrations with external plugins that
-- provide custom statusline: lightline.vim, vim-airline
vim.opt.statusline:prepend("%{coc#status()}%{get(b:,'coc_current_function','')}")

-- mappings for coclist
-- code actions and coc stuff
---@diagnostic disable-next-line: redefined-local
local opts = {silent = true, nowait = true}
-- show all diagnostics
keyset("n", "<space>a", ":<C-u>CocList diagnostics<cr>", opts)
-- manage extensions
keyset("n", "<space>e", ":<C-u>CocList extensions<cr>", opts)
-- show commands
keyset("n", "<space>c", ":<C-u>CocList commands<cr>", opts)
-- find symbol of current document
keyset("n", "<space>o", ":<C-u>CocList outline<cr>", opts)
-- search workspace symbols
keyset("n", "<space>s", ":<C-u>CocList -I symbols<cr>", opts)
-- do default action for next item
keyset("n", "<space>j", ":<C-u>CocNext<cr>", opts)
-- do default action for previous item
keyset("n", "<space>k", ":<C-u>CocPrev<cr>", opts)
-- resume latest coc list
keyset("n", "<space>p", ":<C-u>CocListResume<cr>", opts)