local kind_icons = {
    Text = "",
    Method = "",
    Function = "",
    Constructor = "",
    Field = "",
    Variable = "",
    Class = "ﴯ",
    Interface = "",
    Module = "",
    Property = "ﰠ",
    Unit = "",
    Value = "",
    Enum = "",
    Keyword = "",
    Snippet = "",
    Color = "",
    File = "",
    Reference = "",
    Folder = "",
    EnumMember = "",
    Constant = "",
    Struct = "",
    Event = "",
    Operator = "",
    TypeParameter = ""
}

local has_words_before = function()
    local line, col = unpack(vim.api.nvim_win_get_cursor(0))
    return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

local feedkey = function(key, mode)
    vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(key, true, true, true), mode, true)
end

-- Setup nvim-cmp.
local cmp = require'cmp'

cmp.setup({
    snippet = {
        -- REQUIRED - you must specify a snippet engine
        expand = function(args)
            vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
            -- require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
            -- require('snippy').expand_snippet(args.body) -- For `snippy` users.
            -- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
        end,
    },
    window = {
        -- completion = cmp.config.window.bordered(),
        -- documentation = cmp.config.window.bordered(),
        -- Source for below custom borders: https://github.com/hrsh7th/nvim-cmp/pull/472#issuecomment-1098381334
        completion = {
            border = {'╭', '─', '╮', '│', '╯', '─', '╰', '│'},
            winhighlight = 'Normal:CmpPmenu,FloatBorder:CmpPmenuBorder,CursorLine:PmenuSel,Search:None',
        },
        documentation = {
            border = {'╭', '─', '╮', '│', '╯', '─', '╰', '│'},
            winhighlight = 'Normal:CmpPmenu,FloatBorder:CmpPmenuBorder,CursorLine:PmenuSel,Search:None',
        },
    },
    mapping = cmp.mapping.preset.insert({
        ['<C-b>'] = cmp.mapping.scroll_docs(-4),
        ['<C-f>'] = cmp.mapping.scroll_docs(4),
        ['<C-Space>'] = cmp.mapping.complete(),
        ['<C-e>'] = cmp.mapping.abort(),
        ['<CR>'] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
        ["<Tab>"] = cmp.mapping(function(fallback) -- https://github.com/hrsh7th/nvim-cmp/wiki/Example-mappings for other snippet plugins
            if cmp.visible() then
                cmp.select_next_item()
            elseif vim.fn["vsnip#available"](1) == 1 then
                feedkey("<Plug>(vsnip-expand-or-jump)", "")
            elseif has_words_before() then
                cmp.complete()
            else
                fallback() -- The fallback function sends a already mapped key. In this case, it's probably `<Tab>`.
            end
        end, { "i", "s" }),
        ["<S-Tab>"] = cmp.mapping(function()
            if cmp.visible() then
                cmp.select_prev_item()
            elseif vim.fn["vsnip#jumpable"](-1) == 1 then
                feedkey("<Plug>(vsnip-jump-prev)", "")
            end
        end, { "i", "s" }),
    }),
    sources = cmp.config.sources({
        { name = 'nvim_lsp' },
        { name = 'treesitter' },
        { name = 'vsnip' }, -- For vsnip users.
        -- { name = 'luasnip' }, -- For luasnip users.
        -- { name = 'ultisnips' }, -- For ultisnips users.
        -- { name = 'snippy' }, -- For snippy users.
        { name = 'path', option = { trailing_slash = true }},
        { name = 'nvim_lsp_signature_help' },
    }, {
        { name = 'buffer' },
    }),
    formatting = {
        format = function(entry, vim_item)
            -- Kind icons
            vim_item.kind = string.format('%s %s', kind_icons[vim_item.kind], vim_item.kind) -- This concatonates the icons with the name of the item kind
            -- Source
            vim_item.menu = ({
                buffer = "[Buffer]",
                nvim_lsp = "[LSP]",
                luasnip = "[LuaSnip]",
                nvim_lua = "[Lua]",
                latex_symbols = "[LaTeX]",
            })[entry.source.name]
            return vim_item
        end
    },
})

-- Set configuration for specific filetype.
cmp.setup.filetype('gitcommit', {
    sources = cmp.config.sources({
        { name = 'cmp_git' }, -- You can specify the `cmp_git` source if you were installed it.
    }, {
        { name = 'buffer' },
    })
})

-- Use buffer source for `/` (if you enabled `native_menu`, this won't work anymore).
cmp.setup.cmdline('/', {
    mapping = cmp.mapping.preset.cmdline(),
    sources = {
        { name = 'buffer' }
    }
})

-- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
-- DISABLED due to bug when tabbing for something that doesn't exist, filetype will stop working, nvim-cmp will stop working
-- cmp.setup.cmdline(':', {
--     mapping = cmp.mapping.preset.cmdline(),
--     sources = cmp.config.sources({
--         { name = 'path', option = { trailing_slash = true }}
--     }, {
--         { name = 'cmdline' }
--     })
-- })
