local M = {}
local java_filetypes = { "java" }
local root_markers = { ".git", "mvnw", "gradlew", "pom.xml", "build.gradle" }

-- Utility function to extend or override a config table, similar to the way
-- that Plugin.opts works.
---@param config table
---@param custom function | table | nil
local function extend_or_override(config, custom, ...)
  if type(custom) == "function" then
    config = custom(config, ...) or config
  elseif custom then
    config = vim.tbl_deep_extend("force", config, custom) --[[@as table]]
  end
  return config
end

if pcode.active_java_config.active then
  M = {
    {
      "mfussenegger/nvim-jdtls",
      ft = java_filetypes,
      enabled = pcode.active_java_config.use_nvim_jdtls or false,
      opts = function()
        return {
          root_dir = require("jdtls.setup").find_root(root_markers),
          project_name = function()
            return vim.fn.fnamemodify(vim.fn.getcwd(), ":p:h:t")
          end,

          -- Where are the config and workspace dirs for a project?
          jdtls_config_dir = function(project_name)
            return vim.fn.stdpath("cache") .. "/jdtls/" .. project_name .. "/config"
          end,
          jdtls_workspace_dir = function(project_name)
            return vim.fn.stdpath("cache") .. "/jdtls/" .. project_name .. "/workspace"
          end,
          cmd = { vim.fn.exepath("jdtls") },
          full_cmd = function(opts)
            local project_name = vim.fn.fnamemodify(vim.fn.getcwd(), ":p:h:t")
            local cmd = vim.deepcopy(opts.cmd)
            if project_name then
              vim.list_extend(cmd, {
                "-configuration",
                opts.jdtls_config_dir(project_name),
                "-data",
                opts.jdtls_workspace_dir(project_name),
              })
            end
            return cmd
          end,

          -- These depend on nvim-dap, but can additionally be disabled by setting false here.
          dap = { hotcodereplace = "auto", config_overrides = {} },
          dap_main = {},
          test = true,
          settings = {
            java = {
              inlayHints = {
                parameterNames = {
                  enabled = "all",
                },
              },
            },
          },
        }
      end,
      config = function(_, opts)
        vim.opt_local.shiftwidth = 4
        vim.opt_local.tabstop = 4
        vim.opt_local.softtabstop = 4
        vim.opt_local.ts = 4
        vim.opt_local.expandtab = true

        local mason_registry = require("mason-registry")
        local bundles = {} ---@type string[]
        if opts.dap and mason_registry.is_installed("java-debug-adapter") then
          local java_dbg_pkg = mason_registry.get_package("java-debug-adapter")
          local java_dbg_path = java_dbg_pkg:get_install_path()
          local jar_patterns = {
            java_dbg_path .. "/extension/server/com.microsoft.java.debug.plugin-*.jar",
          }
          -- java-test also depends on java-debug-adapter.
          if opts.test and mason_registry.is_installed("java-test") then
            local java_test_pkg = mason_registry.get_package("java-test")
            local java_test_path = java_test_pkg:get_install_path()
            vim.list_extend(jar_patterns, {
              java_test_path .. "/extension/server/*.jar",
            })
          end
          for _, jar_pattern in ipairs(jar_patterns) do
            for _, bundle in ipairs(vim.split(vim.fn.glob(jar_pattern), "\n")) do
              table.insert(bundles, bundle)
            end
          end
        end

        local function attach_jdtls()
          local fname = vim.api.nvim_buf_get_name(0)

          -- Configuration can be augmented and overridden by opts.jdtls
          local config = extend_or_override({
            cmd = opts.full_cmd(opts),
            root_dir = require("jdtls.setup").find_root(root_markers),
            init_options = {
              bundles = bundles,
            },
            settings = opts.settings,
            -- enable CMP capabilities
            capabilities = require("user.lsp.handlers").capabilities or nil,
          }, opts.jdtls)

          -- Existing server will be reused if the root_dir matches.
          require("jdtls").start_or_attach(config)
          -- not need to require("jdtls.setup").add_commands(), start automatically adds commands
        end

        vim.api.nvim_create_autocmd("FileType", {
          pattern = java_filetypes,
          callback = attach_jdtls,
        })

        -- Setup keymap and dap after the lsp is fully attached.
        -- https://github.com/mfussenegger/nvim-jdtls#nvim-dap-configuration
        -- https://neovim.io/doc/user/lsp.html#LspAttach
        vim.api.nvim_create_autocmd("LspAttach", {
          callback = function(args)
            local client = vim.lsp.get_client_by_id(args.data.client_id)
            if client and client.name == "jdtls" then
              local wk = require("which-key")
              wk.register({
                ["<leader>cx"] = { name = "+extract" },
                ["<leader>cxv"] = { require("jdtls").extract_variable_all, "Extract Variable" },
                ["<leader>cxc"] = { require("jdtls").extract_constant, "Extract Constant" },
                ["gs"] = { require("jdtls").super_implementation, "Goto Super" },
                ["<leader>co"] = { require("jdtls").organize_imports, "Organize Imports" },
              }, { mode = "n", buffer = args.buf })
              wk.register({
                ["<leader>c"] = { name = "+code" },
                ["<leader>cx"] = { name = "+extract" },
                ["<leader>cxm"] = {
                  [[<ESC><CMD>lua require('jdtls').extract_method(true)<CR>]],
                  "Extract Method",
                },
                ["<leader>cxv"] = {
                  [[<ESC><CMD>lua require('jdtls').extract_variable_all(true)<CR>]],
                  "Extract Variable",
                },
                ["<leader>cxc"] = {
                  [[<ESC><CMD>lua require('jdtls').extract_constant(true)<CR>]],
                  "Extract Constant",
                },
              }, { mode = "v", buffer = args.buf })

              if opts.dap and mason_registry.is_installed("java-debug-adapter") then
                -- custom init for Java debugger
                require("jdtls").setup_dap(opts.dap)
                require("jdtls.dap").setup_dap_main_class_configs(opts.dap_main)

                -- Java Test require Java debugger to work
                if opts.test and mason_registry.is_installed("java-test") then
                  -- custom keymaps for Java test runner (not yet compatible with neotest)
                  wk.register({
                    ["<leader>t"] = { name = "+test" },
                    ["<leader>tt"] = { require("jdtls.dap").test_class, "Run All Test" },
                    ["<leader>tr"] = { require("jdtls.dap").test_nearest_method, "Run Nearest Test" },
                    ["<leader>tT"] = { require("jdtls.dap").pick_test, "Run Test" },
                  }, { mode = "n", buffer = args.buf })
                end
              end

              -- User can set additional keymaps in opts.on_attach
              if opts.on_attach then
                opts.on_attach(args)
              end
            end
          end,
        })

        -- Avoid race condition by calling attach the first time, since the autocmd won't fire.
        attach_jdtls()
      end,
    },
    {
      "nvim-treesitter/nvim-treesitter",
      opts = function(_, opts)
        opts.ensure_installed = opts.ensure_installed or {}
        vim.list_extend(opts.ensure_installed, { "java" })
      end,
    },
    {
      "williamboman/mason-lspconfig.nvim",
      opts = function(_, opts)
        opts.ensure_installed = opts.ensure_installed or {}
        vim.list_extend(opts.ensure_installed, { "jdtls" })
      end,
    },
    {
      "stevearc/conform.nvim",
      event = "VeryLazy",
      opts = function(_, opts)
        local package = "lsp_fmt"
        require("user.utils.masoncfg").try_install("java-debug-adapter")
        require("user.utils.masoncfg").try_install("java-test")
        opts.formatters_by_ft.java = { package }
      end,
    },
    {
      "nvim-neotest/neotest",
      dependencies = {
        "nvim-neotest/nvim-nio",
        "nvim-lua/plenary.nvim",
        "antoinemadec/FixCursorHold.nvim",
        "nvim-treesitter/nvim-treesitter",
        "andy-bell101/neotest-java",
      },
      config = function()
        require("neotest").setup({
          adapters = {
            require("neotest-java")({
              -- function to determine which runner to use based on project path
              determine_runner = function(project_root_path)
                -- return should be "maven" or "gradle"
                return pcode.active_java_config.project or "gradle"
              end,
              -- override the builtin runner discovery behaviour to always use given
              -- tool. Default is "nil", so no override
              force_runner = nil,
              -- if the automatic runner discovery can't uniquely determine whether
              -- to use Gradle or Maven, fallback to using this runner. Default is
              -- "gradle"
              fallback_runner = pcode.active_java_config.project or "gradle",
            }),
          },
        })
      end,
      -- stylua: ignore
      keys = {
        { "<leader>T","",desc="  Test"},
        { "<leader>Tt", function() require("neotest").run.run(vim.fn.expand("%")) end, desc = "Run File" },
        { "<leader>Tr", function() require("neotest").run.run() end, desc = "Run Nearest" },
        { "<leader>TT", function() require("neotest").run.run(vim.loop.cwd()) end, desc = "Run All Test Files" },
        { "<leader>Tl", function() require("neotest").run.run_last() end, desc = "Run Last" },
        { "<Leader>Ts", function() require("neotest").summary.toggle() end, desc = "Toggle Summary" },
        { "<leader>To", function() require("neotest").output.open({ enter = true, auto_close = true }) end, desc = "Show Output" },
        { "<Leader>TO", function() require("neotest").output_panel.toggle() end, desc = "Toggle Output Panel" },
        { "<Leader>TS", function() require("neotest").run.stop() end, desc = "Stop" },
      },
    },
  }
end

return M