-- Copilot.
return {
    {
        "zbirenbaum/copilot.lua",
        cmd = "Copilot",
        event = "InsertEnter",
        opts = {
            -- I don't find the panel useful.
            panel = { enabled = false },
            suggestion = {
                auto_trigger = true,
                -- Use alt to interact with Copilot.
                keymap = {
                    -- Disable the built-in mapping, we'll configure it in nvim-cmp.
                    accept = false,
                    accept_word = "<M-w>",
                    accept_line = "<M-l>",
                    next = "<M-]>",
                    prev = "<M-[>",
                    dismiss = "/",
                },
            },
            filetypes = { markdown = true, lua = true, python = true, typescript = true, javascript = true },
        },
        config = function(_, opts)
            local cmp = require("cmp")
            local copilot = require("copilot.suggestion")
            local luasnip = require("luasnip")

            require("copilot").setup(opts)

            local function set_trigger(trigger)
                vim.b.copilot_suggestion_auto_trigger = trigger
                vim.b.copilot_suggestion_hidden = not trigger
            end

            -- Hide suggestions when the completion menu is open.
            cmp.event:on("menu_opened", function()
                if copilot.is_visible() then
                    copilot.dismiss()
                end
                set_trigger(false)
            end)

            -- Disable suggestions when inside a snippet.
            cmp.event:on("menu_closed", function()
                set_trigger(not luasnip.expand_or_locally_jumpable())
            end)
            vim.api.nvim_create_autocmd("User", {
                pattern = { "LuasnipInsertNodeEnter", "LuasnipInsertNodeLeave" },
                callback = function()
                    set_trigger(not luasnip.expand_or_locally_jumpable())
                end,
            })
        end,
    },
}