local log = require "nvim-tree.log"

local M = {}

local function shorten_lhs(lhs)
  lhs = lhs:gsub("LeftMouse", "LM")
  lhs = lhs:gsub("RightMouse", "RM")
  lhs = lhs:gsub("MiddleMouse", "MM")
  lhs = lhs:gsub("ScrollWheelDown", "SWD")
  lhs = lhs:gsub("ScrollWheelUp", "SWU")
  lhs = lhs:gsub("ScrollWheelLeft", "SWL")
  lhs = lhs:gsub("ScrollWheelRight", "SWR")
  return lhs
end

function M.compute_lines()
  local help_lines = { "HELP" }
  local help_hl = { { "NvimTreeRootFolder", 0, 0, #help_lines[1] } }

  local buf_keymaps = vim.api.nvim_buf_get_keymap(vim.api.nvim_get_current_buf(), "n")

  log.line("dev", "%s", vim.inspect(buf_keymaps))

  local processed = {}
  for _, bkm in ipairs(buf_keymaps) do
    local default_keymap = nil
    for _, dkm in ipairs(require("nvim-tree.keymap").DEFAULT_KEYMAPS) do
      if bkm.callback == dkm.callback then
        default_keymap = dkm
      end
    end
    local lhs = shorten_lhs(bkm.lhs)
    if default_keymap then
      table.insert(processed, { lhs, default_keymap.desc.short })
    else
      table.insert(processed, { lhs, "<user>" })
    end
  end

  -- local mappings = vim.tbl_filter(function(v)
  --   return (v.cb ~= nil and v.cb ~= "") or (v.action ~= nil and v.action ~= "")
  -- end, require("nvim-tree.actions").mappings)
  -- local processed = {}
  -- for _, b in pairs(mappings) do
  --   local cb = b.cb
  --   local key = b.key
  --   local name
  --   if cb and cb:sub(1, 35) == require("nvim-tree.config").nvim_tree_callback("test"):sub(1, 35) then
  --     name = cb:match "'[^']+'[^']*$"
  --     name = name:match "'[^']+'"
  --   elseif b.action then
  --     name = b.action
  --   else
  --     name = (b.name ~= nil) and b.name or cb
  --     name = '"' .. name .. '"'
  --   end
  --   table.insert(processed, { key, name, true })
  -- end

  table.sort(processed, function(a, b)
    return (a[3] == b[3] and (a[2] < b[2] or (a[2] == b[2] and #a[1] < #b[1]))) or (a[3] and not b[3])
  end)

  local num = 0
  for _, val in pairs(processed) do
    local keys = type(val[1]) == "string" and { val[1] } or val[1]
    local map_name = val[2]
    local builtin = val[3]
    for _, key in pairs(keys) do
      num = num + 1
      local bind_string = string.format("%6s : %s", key, map_name)
      table.insert(help_lines, bind_string)

      local hl_len = math.max(6, string.len(key)) + 2
      table.insert(help_hl, { "NvimTreeFolderName", num, 0, hl_len })

      if not builtin then
        table.insert(help_hl, { "NvimTreeFileRenamed", num, hl_len, -1 })
      end
    end
  end
  return help_lines, help_hl
end

return M