local misc = require("core.misc")
local map = misc.map

-- helper function to parse output
local function parse_output(proc)
  local result = proc:wait()
  local ret = {}
  if result.code == 0 then
    for line in vim.gsplit(result.stdout, "\n", { plain = true, trimempty = true }) do
      -- Remove trailing slash
      line = line:gsub("/$", "")
      ret[line] = true
    end
  end
  return ret
end

-- build git status cache
local function new_git_status()
  return setmetatable({}, {
    __index = function(self, key)
      local ignore_proc = vim.system(
        { "git", "ls-files", "--ignored", "--exclude-standard", "--others", "--directory" },
        {
          cwd = key,
          text = true,
        }
      )
      local tracked_proc = vim.system({ "git", "ls-tree", "HEAD", "--name-only" }, {
        cwd = key,
        text = true,
      })
      local ret = {
        ignored = parse_output(ignore_proc),
        tracked = parse_output(tracked_proc),
      }

      rawset(self, key, ret)
      return ret
    end,
  })
end
local git_status = new_git_status()

local permission_hlgroups = {
  ["-"] = "NonText",
  ["r"] = "DiagnosticSignWarn",
  ["w"] = "DiagnosticSignHint",
  ["x"] = "DiagnosticSignOk",
}

return { "stevearc/oil.nvim",
  disable = not vim.fn.has("nvim-0.8.0"),
  deps = {
    { "refractalize/oil-git-status.nvim",
      function()
        require("oil-git-status").setup {
          symbols = { -- customize the symbols that appear in the git status columns
            index = {
              ["A"] = "+",
              ["D"] = "-",
              ["M"] = "~",
            },
            working_tree = {
              ["A"] = "+",
              ["D"] = "-",
              ["M"] = "~",
            }
          }
        }
      end
    }
  },
  function()
    -- Clear git status cache on refresh
    local refresh = require("oil.actions").refresh
    local orig_refresh = refresh.callback
    refresh.callback = function(...)
      git_status = new_git_status()
      orig_refresh(...)
    end

    require("oil").setup {
      -- ID is automatically added at the beginning, and name at the end
      -- See :help oil-columns
      columns = {
        {
          "permissions",
          highlight = function(permission_str)
            local hls = {}
            for i = 1, #permission_str do
              local char = permission_str:sub(i, i)
              table.insert(hls, { permission_hlgroups[char], i - 1, i })
            end
            return hls
          end,
        },
        { "size", highlight = "@number" }
      },

      -- Window-local options to use for oil buffers
      win_options = {
        number = false,
        relativenumber = false,
        wrap = false,
        signcolumn = "yes:2",
        cursorcolumn = false,
        foldcolumn = "0",
        spell = false,
        list = false,
        conceallevel = 3,
        concealcursor = "nvic"
      },

      -- Send deleted files to the trash instead of permanently deleting them (:help oil-trash)
      delete_to_trash = false,

      -- Skip the confirmation popup for simple operations (:help oil.skip_confirm_for_simple_edits)
      skip_confirm_for_simple_edits = false,

      -- Selecting a new/moved/renamed file or directory will prompt you to save changes first
      -- (:help prompt_save_on_select_new_entry)
      prompt_save_on_select_new_entry = true,

      -- Oil will automatically delete hidden buffers after this delay
      -- You can set the delay to false to disable cleanup entirely
      -- Note that the cleanup process only starts when none of the oil buffers are currently displayed
      cleanup_delay_ms = 2000,
      lsp_file_methods = {
        -- Enable or disable LSP file operations
        enabled = true,
        -- Time to wait for LSP file operations to complete before skipping
        timeout_ms = 1000,
        -- Set to true to autosave buffers that are updated with LSP willRenameFiles
        -- Set to "unmodified" to only save unmodified buffers
        autosave_changes = "unmodified"
      },

      -- Constrain the cursor to the editable parts of the oil buffer
      -- Set to `false` to disable, or "name" to keep it on the file names
      constrain_cursor = "editable",

      -- Set to true to watch the filesystem for changes and reload oil
      watch_for_changes = false,

      -- Keymaps in oil buffer. Can be any value that `vim.keymap.set` accepts OR a table of keymap
      -- options with a `callback` (e.g. { callback = function() ... end, desc = "", mode = "n" })
      -- Additionally, if it is a string that matches "actions.<name>",
      -- it will use the mapping at require("oil.actions").<name>
      -- Set to `false` to remove a keymap
      -- See :help oil-actions for a list of all available actions
      keymaps = {
        ["g?"] = { "actions.show_help", mode = "n" },
        ["<C-l>"] = "actions.refresh",
        ["<CR>"] = "actions.select",
        ["-"] = { "actions.parent", mode = "n" },
        ["_"] = { "actions.open_cwd", mode = "n" },
        ["`"] = { "actions.cd", mode = "n" },
        ["~"] = { "actions.cd", opts = { scope = "tab" }, mode = "n" },
        ["gs"] = { "actions.change_sort", mode = "n" },
        ["gx"] = "actions.open_external",
        ["g."] = { "actions.toggle_hidden", mode = "n" },
        ["g\\"] = { "actions.toggle_trash", mode = "n" }
      },

      view_options = {
        -- Show files and directories that start with "."
        show_hidden = false,

        -- This function defines what is considered a "hidden" file
        is_hidden_file = function(name, bufnr)
          local dir = require("oil").get_current_dir(bufnr)
          local is_dotfile = vim.startswith(name, ".") and name ~= ".."
          -- if no local directory (e.g. for ssh connections), just hide dotfiles
          if not dir then
            return is_dotfile
          end
          -- dotfiles are considered hidden unless tracked
          if is_dotfile then
            return not git_status[dir].tracked[name]
          end
        end,

        -- This function defines what will never be shown, even when `show_hidden` is set
        is_always_hidden = function(name, bufnr)
          return false
        end,

        -- Sort file names with numbers in a more intuitive order for humans.
        -- Can be "fast", true, or false. "fast" will turn it off for large directories.
        natural_order = "fast",

        -- Sort file and directory names case insensitive
        case_insensitive = false,

        sort = {
          -- sort order can be "asc" or "desc"
          -- see :help oil-columns to see which columns are sortable
          { "type", "asc" },
          { "name", "asc" },
        },

        -- Customize the highlight group for the file name
        highlight_filename = function(entry, is_hidden, is_link_target, is_link_orphan)
          return nil
        end,
      },

      -- Configuration for the floating window in oil.open_float
      float = {
        border = vim.g.border_style
      },

      -- Configuration for the floating action confirmation window
      confirmation = {
        border = vim.g.border_style
      },
      -- Configuration for the floating progress window
      progress = {
        border = vim.g.border_style
      },
      -- Configuration for the floating SSH window
      ssh = {
        border = vim.g.border_style
      },
      -- Configuration for the floating keymaps help window
      keymaps_help = {
        border = vim.g.border_style
      }
    }

    map("n", "-", "<cmd>Oil<CR>")
  end
}