local cmp = require("cmp")
local lspkind = require("lspkind")
local luasnip = require("luasnip")

local has_words_before = function()
    local unpack = unpack or table.unpack
    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 base_mapping = {
    ["<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 },
}
local buffer_mapping = vim.tbl_deep_extend("force", base_mapping, {
    ["<Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
            cmp.select_next_item()
            -- You could replace the expand_or_jumpable() calls with expand_or_locally_jumpable()
            -- that way you will only jump inside the snippet region
        elseif luasnip.expand_or_jumpable() then
            luasnip.expand_or_jump()
        elseif has_words_before() then
            cmp.complete()
        else
            fallback()
        end
    end, { "i", "s" }),

    ["<S-Tab>"] = cmp.mapping(function(fallback)
        if cmp.visible() then
            cmp.select_prev_item()
        elseif luasnip.jumpable(-1) then
            luasnip.jump(-1)
        else
            fallback()
        end
    end, { "i", "s" }),
})

local config = {
    formatting = {
        format = lspkind.cmp_format {
            mode = "symbol_text",
            maxwidth = 50,
            ellipsis_char = "…",
            menu = {
                nvim_lsp = "[LSP]",
                nvim_lsp_signature_help = "[LSP]",
                nvim_lsp_document_symbol = "[LSP]",
                luasnip = "[Snippet]",
                buffer = "[Buffer]",
                path = "[Path]",
                nvim_lua = "[Lua]",
                emoji = "[Emoji]",
            },
        },
    },
    completion = {
        completeopt = "menu,menuone",
    },
    window = {
        completion = {
            side_padding = 0,
            scrollbar = false,
        },
        documentation = {},
    },
    snippet = {
        expand = function(args)
            require("luasnip").lsp_expand(args.body)
        end,
    },
    mapping = cmp.mapping.preset.insert(buffer_mapping),
    sources = cmp.config.sources {
        { name = "luasnip" },
        { name = "nvim_lsp" },
        { name = "neorg" },
        { name = "buffer" },
        { name = "fuzzy_path" },
    },
}

local cmdline_config = {
    mapping = cmp.mapping.preset.cmdline(base_mapping),
    completion = {
        completeopt = "menu,menuone,noselect",
    },
    sources = cmp.config.sources({
        { name = "fuzzy_path" },
    }, {
        { name = "cmdline" },
    }),
}
local search_config = {
    mapping = cmp.mapping.preset.cmdline(base_mapping),
    completion = {
        completeopt = "menu,menuone,noselect",
    },
    sources = {
        { name = "buffer" },
    },
}

cmp.setup(config)
cmp.setup.cmdline("/", search_config)
cmp.setup.cmdline("?", search_config)
cmp.setup.cmdline(":", cmdline_config)