local function get_commenter()
  local commenter = { python = "# ", lua = "-- ", julia = "# ", fennel = ";; ", scala = "// ", r = "# " }
  local bufnr = vim.api.nvim_get_current_buf()
  local ft = vim.api.nvim_buf_get_option(bufnr, "filetype")
  if ft == nil or ft == "" then
    return commenter["python"]
  elseif commenter[ft] == nil then
    return commenter["python"]
  end

  return commenter[ft]
end

local CELL_MARKER = get_commenter() .. "%%"
vim.api.nvim_set_hl(0, "CellMarkerHl", { default = true, bg = "#c5c5c5", fg = "#111111" })

local function miniai_spec(mode)
  local start_line = vim.fn.search("^" .. CELL_MARKER, "bcnW")

  if start_line == 0 then
    start_line = 1
  else
    if mode == "i" then
      start_line = start_line + 1
    end
  end

  local end_line = vim.fn.search("^" .. CELL_MARKER, "nW") - 1
  if end_line == -1 then
    end_line = vim.fn.line("$")
  end

  local last_col = math.max(vim.fn.getline(end_line):len(), 1)

  local from = { line = start_line, col = 1 }
  local to = { line = end_line, col = last_col }

  return { from = from, to = to }
end

local function show_cell_markers()
  require("mini.hipatterns").enable(0, {
    highlighters = {
      marker = { pattern = "^" .. get_commenter() .. "%%%%", group = "CellMarkerHl" },
    },
  })
end

local function select_cell()
  local bufnr = vim.api.nvim_get_current_buf()
  local current_row = vim.api.nvim_win_get_cursor(0)[1]
  local current_col = vim.api.nvim_win_get_cursor(0)[2]

  local start_line = nil
  local end_line = nil

  for line = current_row, 1, -1 do
    local line_content = vim.api.nvim_buf_get_lines(bufnr, line - 1, line, false)[1]
    if line_content:find("^" .. CELL_MARKER) then
      start_line = line
      break
    end
  end
  local line_count = vim.api.nvim_buf_line_count(bufnr)
  for line = current_row + 1, line_count do
    local line_content = vim.api.nvim_buf_get_lines(bufnr, line - 1, line, false)[1]
    if line_content:find("^" .. CELL_MARKER) then
      end_line = line
      break
    end
  end

  if not start_line then
    start_line = 1
  end
  if not end_line then
    end_line = line_count
  end
  return current_row, current_col, start_line, end_line
end

local function execute_cell()
  local current_row, current_col, start_line, end_line = select_cell()
  if start_line and end_line then
    vim.fn.setpos("'<", { 0, start_line + 1, 0, 0 })
    vim.fn.setpos("'>", { 0, end_line - 1, 0, 0 })
    require("iron.core").visual_send()
    vim.api.nvim_win_set_cursor(0, { current_row, current_col })
  end
end

local function delete_cell()
  local _, _, start_line, end_line = select_cell()
  if start_line and end_line then
    local rows_to_select = end_line - start_line - 1
    vim.api.nvim_win_set_cursor(0, { start_line, 0 })
    vim.cmd("normal!V " .. rows_to_select .. "j")
    vim.cmd("normal!d")
    vim.cmd("normal!k")
  end
end

local function navigate_cell(up)
  local is_up = up or false
  local _, _, start_line, end_line = select_cell()
  if is_up and start_line ~= 1 then
    vim.api.nvim_win_set_cursor(0, { start_line - 1, 0 })
  elseif end_line then
    local bufnr = vim.api.nvim_get_current_buf()
    local line_count = vim.api.nvim_buf_line_count(bufnr)
    if end_line ~= line_count then
      vim.api.nvim_win_set_cursor(0, { end_line + 1, 0 })
      _, _, start_line, end_line = select_cell()
      vim.api.nvim_win_set_cursor(0, { end_line - 1, 0 })
    end
  end
end

local function move_cell(dir)
  local search_res
  local result
  if dir == "d" then
    search_res = vim.fn.search("^" .. CELL_MARKER, "W")
    if search_res == 0 then
      result = "last"
    end
  else
    search_res = vim.fn.search("^" .. CELL_MARKER, "bW")
    if search_res == 0 then
      result = "first"
      vim.api.nvim_win_set_cursor(0, { 1, 0 })
    end
  end

  return result
end

local function insert_cell_before(content)
  content = content or CELL_MARKER
  local cell_object = miniai_spec("a")
  vim.api.nvim_buf_set_lines(0, cell_object.from.line - 1, cell_object.from.line - 1, false, { content, "" })
  move_cell("u")
end

local function insert_cell_after(content)
  content = content or CELL_MARKER
  vim.print(content)
  local cell_object = miniai_spec("a")
  vim.api.nvim_buf_set_lines(0, cell_object.to.line, cell_object.to.line, false, { content, "" })
  move_cell("d")
end

local function insert_markdown_cell()
  insert_cell_after(CELL_MARKER .. " [markdown]")
end

local function repl_menu()
  local cmd = require("hydra.keymap-util").cmd

  local hint = [[
 ^
 _a_: Insert Cell After
 _b_: Insert Cell Before
 _e_: Execute Cell
 _j_: Next Cell
 _k_: Previous Cell
 _m_: Insert Markdown Cell
 _x_: Delete Cell
 ^
 _s_: Send Motion
 _l_: Send Line
 _t_: Send Until Cursor
 _f_: Send File
 ^
 _R_: Show REPL
 _C_: Close REPL
 _S_: Restart REPL
 _F_: Focus
 _H_: Hide
 ^
 _c_: Clear
 _L_: Clear Highlight
 _<CR>_: ENTER
 _I_: Interrupt
 ^
 ^ ^  _q_: Quit 
]]

  return {
    name = "REPL",
    hint = hint,
    config = {
      color = "pink",
      invoke_on_body = true,
      hint = {
        border = "rounded",
        position = "bottom-middle",
      },
    },
    mode = "n",
    body = "<A-n>",
    -- stylua: ignore
    heads = {
      { "a", insert_cell_after, desc = "Insert Cell After", },
      { "b", insert_cell_before, desc = "Insert Cell Before", },
      { "e", execute_cell, desc = "Execute Cell", },
      { "j", navigate_cell , desc = "Next Cell", },
      { "k", function() navigate_cell(true) end, desc = "Previous Cell", },
      { "m", insert_markdown_cell, desc = "Insert Markdown Cell", },
      { "x", delete_cell, desc = "Delete Cell", },
      { "s", function() require("iron.core").run_motion("send_motion") end, desc = "Send Motion" },
      { "l", function() require("iron.core").send_line() end, desc = "Send Line" },
      { "t", function() require("iron.core").send_until_cursor() end, desc = "Send Until Cursor" },
      { "f", function() require("iron.core").send_file() end, desc = "Send File" },
      { "L", function() require("iron.marks").clear_hl() end, mode = {"v"}, desc = "Clear Highlight" },
      { "<CR>", function() require("iron.core").send(nil, string.char(13)) end, desc = "ENTER" },
      { "I", function() require("iron.core").send(nil, string.char(03)) end, desc = "Interrupt" },
      { "C", function() require("iron.core").close_repl() end, desc = "Close REPL" },
      { "c", function() require("iron.core").send(nil, string.char(12)) end, desc = "Clear" },
      { "R", cmd("IronRepl"), desc = "REPL" },
      { "S", cmd("IronRestart"), desc = "Restart" },
      { "F", cmd("IronFocus"), desc = "Focus" },
      { "H", cmd("IronHide"), desc = "Hide" },
      { "q", nil, { exit = true, nowait = true, desc = "Exit" } },
    },
  }
end

return {
  {
    "goerz/jupytext.vim",
    build = "pip install jupytext",
    event = "VeryLazy",
    dependencies = { "neovim/nvim-lspconfig" },
    opts = {},
    config = function()
      -- The destination format: 'ipynb', 'markdown' or 'script', or a file extension: 'md', 'Rmd', 'jl', 'py', 'R', ..., 'auto' (script
      -- extension matching the notebook language), or a combination of an extension and a format name, e.g. md:markdown, md:pandoc,
      -- md:myst or py:percent, py:light, py:nomarker, py:hydrogen, py:sphinx. The default format for scripts is the 'light' format,
      -- which uses few cell markers (none when possible). Alternatively, a format compatible with many editors is the 'percent' format,
      -- which uses '# %%' as cell markers. The main formats (markdown, light, percent) preserve notebooks and text documents in a
      -- roundtrip. Use the --test and and --test-strict commands to test the roundtrip on your files. Read more about the available
      -- formats at https://jupytext.readthedocs.io/en/latest/formats.html (default: None)
      vim.g.jupytext_fmt = "py:percent"

      -- Autocmd to set cell markers
      vim.api.nvim_create_autocmd({ "BufEnter" }, { -- "BufWriteCmd"
        group = vim.api.nvim_create_augroup("au_show_cell_markers", { clear = true }),
        pattern = { "*.py", "*.r", "*.ipynb", "*.jl", "*.scala", "*.lua", "*.fnl" },
        callback = function(event)
          show_cell_markers()
        end,
      })
    end,
  },
  {
    "Vigemus/iron.nvim",
    event = "VeryLazy",
    opts = function()
      return {
        config = {
          -- Whether a repl should be discarded or not
          scratch_repl = true,
          -- Your repl definitions come here

          repl_definition = {
            python = require("iron.fts.python").ipython,
            scala = require("iron.fts.scala").scala,
          },
          -- How the repl window will be displayed
          -- See below for more information
          repl_open_cmd = require("iron.view").right("50%"),
        },
        -- If the highliht is on, you can change how it looks
        -- For the available options, check nvim_set_hl
        highlight = {
          italic = true,
        },
        ignore_blank_lines = true, -- ignore blank lines when sending visual select lines
      }
    end,
    -- stylua: ignore
    keys = {
      { "<leader>i", function() end, mode = {"n", "x"}, desc = "+REPL" },
      { "<leader>im", function() end, mode = {"n", "x"}, desc = "+Mark" },
      { "<leader>ire>", execute_cell, desc = "Execute Cell" },
      { "<leader>irx", delete_cell, desc = "Delete Cell" },
      { "<leader>ir]", navigate_cell, desc = "Next Cell" },
      { "<leader>ir[", function() navigate_cell(true) end, desc = "Previous Cell" },
      { "<leader>is", function() require("iron.core").run_motion("send_motion") end, desc = "Send Motion" },
      { "<leader>is", function() require("iron.core").visual_send() end, mode = {"v"}, desc = "Send" },
      { "<leader>il", function() require("iron.core").send_line() end, desc = "Send Line" },
      { "<leader>it", function() require("iron.core").send_until_cursor() end, desc = "Send Until Cursor" },
      { "<leader>if", function() require("iron.core").send_file() end, desc = "Send File" },
      { "<leader>iL", function() require("iron.marks").clear_hl() end, mode = {"v"}, desc = "Clear Highlight" },
      { "<leader>i<cr>", function() require("iron.core").send(nil, string.char(13)) end, desc = "ENTER" },
      { "<leader>iI", function() require("iron.core").send(nil, string.char(03)) end, desc = "Interrupt" },
      { "<leader>iC", function() require("iron.core").close_repl() end, desc = "Close REPL" },
      { "<leader>ic", function() require("iron.core").send(nil, string.char(12)) end, desc = "Clear" },
      { "<leader>ims", function() require("iron.core").send_mark() end, desc = "Send Mark" },
      { "<leader>imm", function() require("iron.core").run_motion("mark_motion") end, desc = "Mark Motion" },
      { "<leader>imv", function() require("iron.core").mark_visual() end, mode = {"v"}, desc = "Mark Visual" },
      { "<leader>imr", function() require("iron.marks").drop_last() end, desc = "Remove Mark" },
      { "<leader>iR", "<cmd>IronRepl<cr>", desc = "REPL" },
      { "<leader>iS", "<cmd>IronRestart<cr>", desc = "Restart" },
      { "<leader>iF", "<cmd>IronFocus<cr>", desc = "Focus" },
      { "<leader>iH", "<cmd>IronHide<cr>", desc = "Hide" },
    },
    config = function(_, opts)
      local iron = require("iron.core")
      iron.setup(opts)
    end,
  },
  {
    "folke/which-key.nvim",
    event = "VeryLazy",
    opts = {
      defaults = {
        ["<leader>i"] = { name = "+REPL" },
        ["<leader>im"] = { name = "+Mark" },
      },
    },
  },
  {
    "anuvyklack/hydra.nvim",
    event = { "VeryLazy" },
    opts = {
      specs = {
        repl = repl_menu,
      },
    },
    config = function(_, opts)
      local hydra = require("hydra")
      for s, _ in pairs(opts.specs) do
        hydra(opts.specs[s]())
      end
    end,
  },
  {
    "echasnovski/mini.ai",
    opts = function(_, opts)
      opts.custom_textobjects = vim.tbl_extend("force", opts.custom_textobjects, { h = miniai_spec })
    end,
  },
}