{ config, pkgs, ... }:
let
  c = config.theme.colors;
in
{
  programs.neovim = {
    enable   = true;
    viAlias  = true;
    vimAlias = true;

    extraPackages = with pkgs; [
      lua-language-server
      nil
      nixfmt
      ripgrep
      fd
    ];

    # Set mapleader before any plugin config blocks run
    extraConfig = ''
      let g:mapleader = "\<Space>"
      let g:maplocalleader = "\<Space>"
    '';

    plugins = with pkgs.vimPlugins; [
      # ── Core dependencies ──────────────────────────────────────────────
      plenary-nvim
      nvim-web-devicons

      # ── Theme ──────────────────────────────────────────────────────────
      gruvbox-nvim

      # ── Syntax highlighting ────────────────────────────────────────────
      {
        plugin = nvim-treesitter.withAllGrammars;
        type   = "lua";
        config = ''
          require("nvim-treesitter").setup({
            highlight = { enable = true },
            indent    = { enable = true },
          })
        '';
      }

      # ── Completion (must come before lspconfig) ────────────────────────
      luasnip
      cmp-nvim-lsp
      cmp-buffer
      cmp-path
      cmp_luasnip
      {
        plugin = nvim-cmp;
        type   = "lua";
        config = ''
          local cmp     = require("cmp")
          local luasnip = require("luasnip")

          cmp.setup({
            snippet = {
              expand = function(args)
                luasnip.lsp_expand(args.body)
              end,
            },
            mapping = cmp.mapping.preset.insert({
              ["<C-Space>"] = cmp.mapping.complete(),
              ["<C-e>"]     = cmp.mapping.abort(),
              ["<CR>"]      = cmp.mapping.confirm({ select = false }),
              ["<Tab>"] = cmp.mapping(function(fallback)
                if cmp.visible() then
                  cmp.select_next_item()
                elseif luasnip.expand_or_jumpable() then
                  luasnip.expand_or_jump()
                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" }),
            }),
            sources = cmp.config.sources({
              { name = "nvim_lsp" },
              { name = "luasnip" },
              { name = "buffer" },
              { name = "path" },
            }),
          })
        '';
      }

      # ── LSP ────────────────────────────────────────────────────────────
      {
        plugin = nvim-lspconfig;
        type   = "lua";
        config = ''
          local capabilities = require("cmp_nvim_lsp").default_capabilities()

          vim.api.nvim_create_autocmd("LspAttach", {
            callback = function(event)
              local map = function(keys, func, desc)
                vim.keymap.set("n", keys, func, { buffer = event.buf, desc = desc })
              end
              map("gd",         vim.lsp.buf.definition,   "Go to definition")
              map("gr",         vim.lsp.buf.references,    "Find references")
              map("K",          vim.lsp.buf.hover,         "Hover docs")
              map("<leader>rn", vim.lsp.buf.rename,        "Rename symbol")
              map("<leader>ca", vim.lsp.buf.code_action,   "Code action")
              map("<leader>ld", vim.diagnostic.open_float, "Show diagnostics")
              map("<leader>ln", vim.diagnostic.goto_next,  "Next diagnostic")
              map("<leader>lp", vim.diagnostic.goto_prev,  "Prev diagnostic")
            end,
          })

          vim.lsp.config("lua_ls", {
            capabilities = capabilities,
            settings = {
              Lua = {
                diagnostics = { globals = { "vim" } },
              },
            },
          })
          vim.lsp.enable("lua_ls")

          vim.lsp.config("nil_ls", {
            capabilities = capabilities,
          })
          vim.lsp.enable("nil_ls")
        '';
      }

      # ── File explorer ──────────────────────────────────────────────────
      {
        plugin = nvim-tree-lua;
        type   = "lua";
        config = ''
          require("nvim-tree").setup()
          vim.keymap.set("n", "<leader>e", "<cmd>NvimTreeToggle<cr>")
        '';
      }

      # ── Statusline ─────────────────────────────────────────────────────
      {
        plugin = lualine-nvim;
        type   = "lua";
        config = ''
          require("lualine").setup({
            options = { theme = "gruvbox-material" },
          })
        '';
      }

      # ── Buffer tabs ────────────────────────────────────────────────────
      {
        plugin = bufferline-nvim;
        type   = "lua";
        config = ''
          require("bufferline").setup()
          vim.keymap.set("n", "<S-l>", "<cmd>BufferLineCycleNext<cr>", { desc = "Next buffer" })
          vim.keymap.set("n", "<S-h>", "<cmd>BufferLineCyclePrev<cr>", { desc = "Prev buffer" })
          vim.keymap.set("n", "<leader>x", "<cmd>bdelete<cr>",          { desc = "Close buffer" })
        '';
      }

      # ── Fuzzy finder ───────────────────────────────────────────────────
      {
        plugin = telescope-nvim;
        type   = "lua";
        config = ''
          local builtin = require("telescope.builtin")
          vim.keymap.set("n", "<leader>ff", builtin.find_files,  { desc = "Find files" })
          vim.keymap.set("n", "<leader>fg", builtin.live_grep,   { desc = "Live grep" })
          vim.keymap.set("n", "<leader>fb", builtin.buffers,     { desc = "Find buffers" })
          vim.keymap.set("n", "<leader>fr", builtin.oldfiles,    { desc = "Recent files" })
          vim.keymap.set("n", "<leader>fs", builtin.grep_string, { desc = "Find word under cursor" })
        '';
      }

      # ── Git ────────────────────────────────────────────────────────────
      {
        plugin = gitsigns-nvim;
        type   = "lua";
        config = ''
          require("gitsigns").setup({
            on_attach = function(bufnr)
              local gs  = require("gitsigns")
              local map = function(mode, keys, func, desc)
                vim.keymap.set(mode, keys, func, { buffer = bufnr, desc = desc })
              end
              map("n", "<leader>gn", gs.next_hunk,    "Next hunk")
              map("n", "<leader>gp", gs.prev_hunk,    "Prev hunk")
              map("n", "<leader>gh", gs.preview_hunk, "Preview hunk")
              map("n", "<leader>gb", gs.blame_line,   "Blame line")
              map("n", "<leader>gs", gs.stage_hunk,   "Stage hunk")
              map("n", "<leader>gr", gs.reset_hunk,   "Reset hunk")
            end,
          })
        '';
      }

      # ── Comment toggling ───────────────────────────────────────────────
      {
        plugin = comment-nvim;
        type   = "lua";
        config = ''require("Comment").setup()'';
      }

      # ── Indentation guides ─────────────────────────────────────────────
      {
        plugin = indent-blankline-nvim;
        type   = "lua";
        config = ''require("ibl").setup()'';
      }
    ];

    initLua = ''
      require("gruvbox").setup({
        contrast = "medium",
        transparent_mode = false,
      })
      vim.cmd("colorscheme gruvbox")

      vim.opt.number         = true
      vim.opt.relativenumber = true
      vim.opt.tabstop        = 2
      vim.opt.shiftwidth     = 2
      vim.opt.expandtab      = true
      vim.opt.smartindent    = true
      vim.opt.ignorecase     = true
      vim.opt.smartcase      = true
      vim.opt.hlsearch       = false
      vim.opt.termguicolors  = true
      vim.opt.signcolumn     = "yes"
      vim.opt.cursorline     = true
      vim.opt.scrolloff      = 8
      vim.opt.wrap           = false
      vim.opt.splitright     = true
      vim.opt.splitbelow     = true
      vim.opt.clipboard      = "unnamedplus"

      local map = vim.keymap.set
      map("n", "<C-h>", "<C-w>h")
      map("n", "<C-j>", "<C-w>j")
      map("n", "<C-k>", "<C-w>k")
      map("n", "<C-l>", "<C-w>l")
      map("v", "J", ":m '>+1<cr>gv=gv")
      map("v", "K", ":m '<-2<cr>gv=gv")
      map("n", "<C-d>", "<C-d>zz")
      map("n", "<C-u>", "<C-u>zz")
      map("n", "<leader>w", "<cmd>w<cr>")
      map("n", "<leader>q", "<cmd>q<cr>")
    '';
  };
}