local uv = vim.uv or vim.loop
local path = require "fzf-lua.path"
local utils = require "fzf-lua.utils"
local libuv = require "fzf-lua.libuv"
local actions = require "fzf-lua.actions"
local devicons = require "fzf-lua.devicons"

local M = {}

-- set this so that make_entry won't get nil err when setting remotely
M.__resume_data = {}

M.resume_get = function(what, opts)
  assert(opts.__resume_key)
  if type(opts.__resume_get) == "function" then
    -- override was set (live_grep, live_workspace_symbols)
    return opts.__resume_get(what, opts)
  end
  local fn_key = tostring(opts.__resume_key):match("[^%s]+$")
  what = string.format("__resume_map.%s%s", fn_key,
    type(what) == "string" and ("." .. what) or "")
  -- _G.dump("resume_get", what, utils.map_get(M, what))
  return utils.map_get(M, what)
end

-- store an option in both the resume options and provider specific __call_opts
M.resume_set = function(what, val, opts)
  assert(opts.__resume_key)
  if type(opts.__resume_set) == "function" then
    -- override was set (live_grep, live_workspace_symbols)
    return opts.__resume_set(what, val, opts)
  end
  local fn_key = tostring(opts.__resume_key):match("[^%s]+$")
  local key1 = string.format("__resume_map.%s%s", fn_key,
    type(what) == "string" and ("." .. what) or "")
  utils.map_set(M, key1, val)
  if type(what) == "string" then
    local key2 = string.format("__resume_data.opts.%s", what)
    utils.map_set(M, key2, val)
  end
  -- backward compatibility for users using `get_last_query`
  if what == "query" then
    utils.map_set(M, "__resume_data.last_query", val)
    -- store in opts for convenience in action callbacks
    opts.last_query = val
  end
  -- _G.dump("resume_set", key1, utils.map_get(M, key1))
end

---@param opts {resume: boolean, __call_opts: table}
---@return table
function M.resume_opts(opts)
  assert(opts.resume and opts.__call_opts)
  local __call_opts = M.resume_get(nil, opts)
  opts = vim.tbl_deep_extend("keep", opts, __call_opts or {})
  opts.__call_opts = vim.tbl_deep_extend("keep", opts.__call_opts, __call_opts or {})
  -- _G.dump("__call_opts", opts.__call_opts)
  return opts
end

-- proxy table (with logic) for accessing the global config
M.setup_opts = {}
M.globals = setmetatable({}, {
  __index = function(_, index)
    -- build normalized globals, option priority below:
    --   (1) provider specific globals (post-setup)
    --   (2) generic global-defaults (post-setup), i.e. `setup({ defaults = { ... } })`
    --   (3) fzf-lua's true defaults (pre-setup, static)
    local fzflua_default = utils.map_get(M.defaults, index)
    local setup_default = utils.map_get(M.setup_opts.defaults, index)
    local setup_value = utils.map_get(M.setup_opts, index)
    local function build_bind_tables(keys)
      -- bind tables are logical exception, do not merge with defaults unless `[1] == true`
      -- normalize all binds as lowercase to prevent duplicate keys (#654)
      local ret = {}
      for _, k in ipairs(keys) do
        ret[k] = setup_value and type(setup_value[k]) == "table"
            and vim.tbl_deep_extend("keep", utils.tbl_deep_clone(setup_value[k]),
              setup_value[k][1] == true and fzflua_default[k] or {})
            or utils.tbl_deep_clone(fzflua_default[k])
        if ret[k] then
          -- Remove the [1] indicating inheritance from defaults and
          -- exclude case-sensitive alt-binds from being lowercased
          ret[k][1] = nil
          ret[k] = utils.map_tolower(ret[k], "^alt%-%a$")
        end
      end
      return ret
    end
    if index == "actions" then
      return build_bind_tables({ "files", "buffers" })
    elseif index == "keymap" then
      return build_bind_tables({ "fzf", "builtin" })
    end
    -- values that aren't tables can't get merged, return highest priority
    if setup_value ~= nil and type(setup_value) ~= "table" then
      return setup_value
    elseif setup_default ~= nil and type(setup_default) ~= "table" then
      return setup_default
    elseif fzflua_default ~= nil and type(fzflua_default) ~= "table" then
      return fzflua_default
    elseif fzflua_default == nil and setup_value == nil then
      return
    end
    -- (1) use fzf-lua's true defaults (pre-setup) as our options base
    local ret = utils.tbl_deep_clone(fzflua_default) or {}
    if (fzflua_default and (fzflua_default.actions or fzflua_default._actions))
        or (setup_value and (setup_value.actions or setup_value._actions)) then
      -- (2) the existence of the `actions` key implies we're dealing with a picker
      -- override global provider defaults supplied by the user's setup `defaults` table
      ret = vim.tbl_deep_extend("force", ret, M.setup_opts.defaults or {})
    end
    -- (3) override with the specific provider options from the users's `setup` option
    ret = vim.tbl_deep_extend("force", ret, utils.map_get(M.setup_opts, index) or {})
    return ret
  end,
  __newindex = function(_, index, _)
    assert(false, string.format("modifying globals directly isn't allowed [index: %s]", index))
  end
})

do
  -- store circular refs for globals/defaults
  -- used by M.globals.__index and M.defaults.<provider>._actions
  local m = require("fzf-lua.defaults")
  M.defaults = m.defaults
  m.globals = M.globals
end

local eval = function(v, ...)
  if vim.is_callable(v) then return v(...) end
  return v
end

---@param opts table<string, unknown>|fun():table?
---@param globals string|table?
---@param __resume_key string?
function M.normalize_opts(opts, globals, __resume_key)
  if not opts then opts = {} end

  -- opts can also be a function that returns an opts table
  if type(opts) == "function" then
    opts = opts()
  end

  -- expand opts that were specified with a dot
  -- e.g. `:FzfLua files winopts.border=single`
  do
    -- convert keys only after full iteration or we will
    -- miss keys due to messing with map ordering
    local to_convert = {}
    for k, _ in pairs(opts) do
      if k:match("%.") then
        table.insert(to_convert, k)
      end
    end
    for _, k in ipairs(to_convert) do
      utils.map_set(opts, k, opts[k])
      opts[k] = nil
    end
  end

  -- save the user's original call params separately
  opts.__call_opts = opts.__call_opts or utils.deepcopy(opts)
  opts.__call_fn = utils.__FNCREF2__()

  -- resume storage data lookup key, default to the calling function ref
  -- __FNCREF2__ will use the 2nd function ref in the stack (calling fn)
  opts.__resume_key = __resume_key
      or opts.__resume_key
      or (type(globals) == "string" and globals)
      or (type(globals) == "table" and globals.__resume_key)
      or utils.__FNCREF2__()

  if type(globals) == "string" then
    -- globals is a string, generate provider globals
    globals = M.globals[globals]
    assert(type(globals) == "table")
  else
    -- backward compat: globals sent directly as table
    -- merge with setup options "defaults" table
    globals = vim.tbl_deep_extend("keep", globals, M.setup_opts.defaults or {})
  end

  -- merge current opts with revious __call_opts on resume
  if opts.resume then
    opts = M.resume_opts(opts)
  end

  local function convert_bool_opts()
    -- Enforce conversion of boolean options that are tables with `enabled`
    -- property, i.e. `winopts.treesitter = true` will be converted to
    -- `winopts = { treesitter = { enabled = true, <defaults> } }`
    -- Running a command and setting sub-values implies `enabled=true`, e.g:
    --   `:FzfLua blines winopts.treesitter.fzf_colors=false`
    --   `:FzfLua blines winopts.treesitter.fzf_colors={hl="-1:underline"}`
    -- So the above will be converted to:
    -- `winopts = { treesitter = { enabled = true, fzf_colors = false, <defaults> } }`
    -- NOTE:  this function runs once before merging with globals and once
    -- later down the line (after merges with globals/defaults), this is done
    -- so that commands as the example above won't inherit `{ enabled = false }`
    -- from the defaults (e.g. the default is `winopts.treesitter.enabled = false`)
    for k, vfrom in pairs({
      ["winopts.treesitter"] = "winopts.treesitter",
      ["previewer.treesitter"] = "previewers.builtin.treesitter",
      ["previewer.render_markdown"] = "previewers.builtin.render_markdown",
    })
    do
      local v = utils.map_get(opts, k)
      if v == false then
        utils.map_set(opts, k, { enabled = false })
      elseif v == true or type(v) == "table" then
        local newv = vim.tbl_deep_extend("keep", type(v) == "table" and v or {},
          { enabled = true }, utils.map_get(M.defaults, vfrom) or {})
        utils.map_set(opts, k, newv)
      end
    end
  end
  convert_bool_opts()

  -- normalize all binds as lowercase or we can have duplicate keys (#654)
  ---@param m {fzf: table<string, unknown>, builtin: table<string, unknown>}
  ---@return {fzf: table<string, unknown>, builtin: table<string, unknown>}?
  local keymap_tolower = function(m, exclude_patterns)
    return m and {
      fzf = utils.map_tolower(m.fzf, exclude_patterns),
      builtin = utils.map_tolower(m.builtin, exclude_patterns),
    } or nil
  end
  local exclude_case_sensitive_alt = "^alt%-%a$"
  opts.keymap = keymap_tolower(eval(opts.keymap, opts), exclude_case_sensitive_alt)
  opts.actions = utils.map_tolower(eval(opts.actions, opts), exclude_case_sensitive_alt)
  globals.keymap = keymap_tolower(eval(globals.keymap, opts), exclude_case_sensitive_alt)
  globals.actions = utils.map_tolower(eval(globals.actions, opts), exclude_case_sensitive_alt)

  -- inherit from globals.actions?
  if type(globals._actions) == "function" then
    globals.actions = vim.tbl_deep_extend("keep", globals.actions or {}, globals._actions())
  end

  -- merge with provider defaults from globals (defaults + setup options)
  opts = vim.tbl_deep_extend("keep", opts, utils.tbl_deep_clone(globals))

  -- Backward compat: merge `winopts` with outputs from `winopts_fn`
  local winopts_fn = opts.winopts_fn or M.globals.winopts_fn
  if type(winopts_fn) == "function" then
    if not opts.silent then
      utils.warn(
        "Deprecated option: 'winopts_fn' -> 'winopts'. Add 'silent=true' to hide this message.")
    end
    local ret = winopts_fn(opts) or {}
    if not utils.tbl_isempty(ret) and (not opts.winopts or type(opts.winopts) == "table") then
      opts.winopts = vim.tbl_deep_extend("force", opts.winopts or {}, ret)
    end
  end

  -- Merge values from globals
  for _, k in ipairs({
    "winopts", "keymap", "fzf_opts", "fzf_colors", "fzf_tmux_opts", "hls"
  }) do
    local setup_val = M.globals[k]
    if type(setup_val) == "function" then
      setup_val = setup_val(opts)
      if type(setup_val) == "table" then
        local default_val = utils.map_get(M.defaults, k)
        if type(default_val) == "table" then
          setup_val = vim.tbl_deep_extend("force", {}, default_val, setup_val)
        end
      end
    end
    if type(setup_val) == "table" then
      -- must clone or map will be saved as reference
      -- and then overwritten if found in 'backward_compat'
      setup_val = utils.tbl_deep_clone(setup_val)
    end
    if opts[k] == nil then
      opts[k] = setup_val
    else
      if type(opts[k]) == "function" then
        opts[k] = opts[k](opts)
      end
      if type(opts[k]) == "table" then
        opts[k] = vim.tbl_deep_extend("keep",
          opts[k], type(setup_val) == "table" and setup_val or {})
      end
    end
  end

  -- backward compat: no-value flags should be set to `true`, in the past these
  -- would be set to an empty string which would now translate into a shell escaped
  -- string as we automatically shell escape all fzf_opts
  for k, v in pairs(opts.fzf_opts) do
    if v == "" then opts.fzf_opts[k] = true end
  end

  -- backward compat for `winopts.preview.{wrap|hidden}`
  for k, v in pairs({ wrap = "nowrap", hidden = "nohidden" }) do
    local val = utils.map_get(opts, "winopts.preview." .. k)
    if type(val) == "string" then
      utils.map_set(opts, "winopts.preview." .. k, not val:match(v))
    end
  end

  -- fzf.vim's `g:fzf_history_dir` (#1127)
  if vim.g.fzf_history_dir and opts.fzf_opts["--history"] == nil then
    local histdir = libuv.expand(vim.g.fzf_history_dir)
    if vim.fn.isdirectory(histdir) == 0 then
      pcall(vim.fn.mkdir, histdir)
    end
    if vim.fn.isdirectory(histdir) == 1 and type(opts.__resume_key) == "string" then
      opts.fzf_opts["--history"] = path.join({ histdir, opts.__resume_key })
    end
  end

  -- Merge arrays from globals|defaults, can't use 'vim.tbl_xxx'
  -- for these as they only work for maps, ie. '{ key = value }'
  for _, k in ipairs({ "file_ignore_patterns" }) do
    for _, m in ipairs({ globals, M.globals }) do
      if m[k] then
        for _, item in ipairs(m[k]) do
          if not opts[k] then opts[k] = {} end
          table.insert(opts[k], item)
        end
      end
    end
  end

  -- these options are copied from globals unless specifically set
  -- also check if we need to override 'opts.prompt' from cli args
  -- if we don't override 'opts.prompt' 'FzfWin.save_query' will
  -- fail to remove the prompt part from resume saved query (#434)
  for _, s in ipairs({
    "fzf_args",
    "fzf_cli_args",
    "fzf_raw_args",
    "file_icon_padding",
    "dir_icon",
    "help_open_win",
  }) do
    if opts[s] == nil then
      opts[s] = M.globals[s]
    end
    local pattern_prefix = "%-%-prompt="
    local pattern_prompt = ".-"
    local surround = type(opts[s]) == "string" and opts[s]:match(pattern_prefix .. "(.)")
    -- prompt was set without surrounding quotes
    -- technically an error but we can handle it gracefully instead
    if surround and surround ~= [[']] and surround ~= [["]] then
      surround = ""
      pattern_prompt = "[^%s]+"
    end
    if surround then
      local pattern_capture = pattern_prefix ..
          ("%s(%s)%s"):format(surround, pattern_prompt, surround)
      local pattern_gsub = pattern_prefix ..
          ("%s%s%s"):format(surround, pattern_prompt, surround)
      if opts[s]:match(pattern_gsub) then
        opts.prompt = opts[s]:match(pattern_capture)
        opts[s] = opts[s]:gsub(pattern_gsub, "")
      end
    end
  end

  -- backward compatibility, rhs overrides lhs
  -- (rhs being the "old" option)
  local backward_compat = {
    { "winopts.row",                            "winopts.win_row" },
    { "winopts.col",                            "winopts.win_col" },
    { "winopts.width",                          "winopts.win_width" },
    { "winopts.height",                         "winopts.win_height" },
    { "winopts.border",                         "winopts.win_border" },
    { "winopts.on_create",                      "winopts.window_on_create" },
    { "winopts.preview.wrap",                   "preview_wrap" },
    { "winopts.preview.border",                 "preview_border" },
    { "winopts.preview.hidden",                 "preview_opts" },
    { "winopts.preview.vertical",               "preview_vertical" },
    { "winopts.preview.horizontal",             "preview_horizontal" },
    { "winopts.preview.layout",                 "preview_layout" },
    { "winopts.preview.flip_columns",           "flip_columns" },
    { "winopts.preview.default",                "default_previewer" },
    { "winopts.preview.delay",                  "previewers.builtin.delay" },
    { "winopts.preview.title",                  "previewers.builtin.title" },
    { "winopts.preview.title_pos",              "winopts.preview.title_align" },
    { "winopts.preview.scrollbar",              "previewers.builtin.scrollbar" },
    { "winopts.preview.scrollchar",             "previewers.builtin.scrollchar" },
    { "cwd_header",                             "show_cwd_header" },
    { "cwd_prompt",                             "show_cwd_prompt" },
    { "resume",                                 "continue_last_search" },
    { "resume",                                 "repeat_last_search" },
    { "jump1",                                  "jump_to_single_result" },
    { "jump1_action",                           "jump_to_single_result_action" },
    { "hls.normal",                             "winopts.hl_normal" },
    { "hls.border",                             "winopts.hl_border" },
    { "hls.cursor",                             "previewers.builtin.hl_cursor" },
    { "hls.cursorline",                         "previewers.builtin.hl_cursorline" },
    { "hls",                                    "winopts.hl" },
    { "previewer.treesitter.enabled",           "previewer.treesitter.enable" },
    { "previewer.treesitter.disabled",          "previewer.treesitter.disable" },
    { "previewers.builtin.treesitter.enabled",  "previewers.builtin.treesitter.enable" },
    { "previewers.builtin.treesitter.disabled", "previewers.builtin.treesitter.disable" },
  }

  -- iterate backward compat map, retrieve values from opts or globals
  for _, t in ipairs(backward_compat) do
    local new_key, old_key = t[1], t[2]
    local v_opts = utils.map_get(opts, old_key)
    local old_val = v_opts == nil and utils.map_get(M.globals, old_key) or v_opts
    local new_val = utils.map_get(opts, new_key)
    if old_val ~= nil then
      if type(old_val) == "table" and type(new_val) == "table" then
        utils.map_set(opts, new_key, vim.tbl_deep_extend("keep", new_val, old_val))
      else
        utils.map_set(opts, new_key, old_val)
      end
      utils.map_set(opts, old_key, nil)
      if not opts.silent then
        utils.warn(string.format(
          "Deprecated option: '%s' -> '%s'. Add 'silent=true' to hide this message.",
          old_key, new_key))
      end
    end
  end

  -- Backward compat, "default" action is "enter"
  if opts.actions then
    opts.actions.enter = opts.actions.default or opts.actions.enter
    opts.actions.default = nil
  end

  -- Setup completion options
  if opts.complete then
    opts.actions = opts.actions or {}
    opts.actions.enter = actions.complete
  end

  -- Merge highlight overrides with defaults, we only do this after the
  -- backward compat copy due to the migration of `winopts.hl` -> `hls`
  opts.hls = vim.tbl_deep_extend("keep", opts.hls or {}, M.globals.__HLS)

  -- Setup formatter options
  if opts.formatter then
    local _fmt_ver = 1
    if type(opts.formatter) == "table" then
      _fmt_ver = opts.formatter.v or opts.formatter[2] or _fmt_ver
      opts.formatter = opts.formatter.name or opts.formatter[1]
    end
    local _fmt = M.globals["formatters." .. opts.formatter]
    if _fmt then
      opts._fmt = opts._fmt or {}
      if opts._fmt.to == nil then
        opts._fmt.to = _fmt.to or _fmt._to and _fmt._to(opts, _fmt_ver) or nil
      end
      if opts._fmt.from == nil then
        opts._fmt.from = _fmt.from
      end
      if type(opts._fmt.to) == "string" then
        -- store the string function as backup for `make_entry.preprocess`
        opts._fmt._to = opts._fmt.to
        opts._fmt.to = loadstring(tostring(opts._fmt.to))()
      end
      if type(_fmt.enrich) == "function" then
        -- formatter requires enriching the config (fzf_opts, etc)
        opts = _fmt.enrich(opts, _fmt_ver) or opts
      end
    else
      utils.warn(("Invalid formatter '%s', ignoring."):format(opts.formatter))
    end
  end

  -- Exclude file icons from the fuzzy matching (#1080)
  if opts.file_icons and opts._fzf_nth_devicons and not opts.fzf_opts["--delimiter"] then
    opts.fzf_opts["--nth"] = opts.fzf_opts["--nth"] or "-1.."
    opts.fzf_opts["--delimiter"] = string.format("[%s]", utils.nbsp)
  end

  if type(opts.previewer) == "function" then
    -- we use a function so the user can override
    -- globals.winopts.preview.default
    opts.previewer = opts.previewer()
  end
  -- "Shortcut" values to the builtin previewer
  -- merge with builtin previewer defaults
  if type(opts.previewer) == "table"
      or opts.previewer == true
      or opts.previewer == "hidden"
      or opts.previewer == "nohidden"
  then
    -- of type string, can only be "hidden|nohidden"
    if type(opts.previewer) == "string" then
      assert(opts.previewer == "hidden" or opts.previewer == "nohidden")
      utils.map_set(opts, "winopts.preview.hidden", opts.previewer ~= "nohidden")
    end
    opts.previewer = vim.tbl_deep_extend("keep",
      type(opts.previewer) == "table" and opts.previewer or {},
      M.globals.previewers.builtin)
  end

  -- Convert again in case the bool option came from global opts
  convert_bool_opts()

  -- Auto-generate fzf's colorscheme
  opts.fzf_colors = type(opts.fzf_colors) == "table" and opts.fzf_colors
      or opts.fzf_colors == true and { true } or {}

  -- Inerherit from fzf.vim's g:fzf_colors
  -- fzf.vim:
  --   vim.g.fzf_colors = {
  --     ["fg"] = { "fg" , "Comment", "Normal" }
  --   }
  -- fzf-lua:
  --   fzf_colors = {
  --     ["fg"] = { "fg" , { "Comment", "Normal" } }
  --   }
  opts.fzf_colors = vim.tbl_extend("keep", opts.fzf_colors,
    vim.tbl_map(function(v)
      -- Value isn't guaranteed a table, e.g:
      --   vim.g.fzf_colors = { ["gutter"] = "-1" }
      if type(v) ~= "table" then return tostring(v) end
      -- We accept both fzf.vim and fzf-lua style values
      if type(v[2]) == "table" then return v end
      local new_v = { v[1], { v[2] } }
      for i = 3, #v do
        table.insert(new_v[2], v[i])
      end
      return new_v
    end, type(vim.g.fzf_colors) == "table" and vim.g.fzf_colors or {}))

  if opts.fzf_colors[1] == true then
    opts.fzf_colors[1] = nil
    opts.fzf_colors = vim.tbl_deep_extend("keep", opts.fzf_colors, {
      ["fg"]        = { "fg", opts.hls.fzf.normal },
      ["bg"]        = { "bg", opts.hls.fzf.normal },
      ["hl"]        = { "fg", opts.hls.fzf.match },
      ["fg+"]       = { "fg", { opts.hls.fzf.cursorline, opts.hls.fzf.normal } },
      ["bg+"]       = { "bg", opts.hls.fzf.cursorline },
      ["hl+"]       = { "fg", opts.hls.fzf.match },
      ["info"]      = { "fg", opts.hls.fzf.info },
      ["border"]    = { "fg", opts.hls.fzf.border },
      ["gutter"]    = { "bg", opts.hls.fzf.gutter },
      ["query"]     = { "fg", opts.hls.fzf.query, "regular" },
      ["prompt"]    = { "fg", opts.hls.fzf.prompt },
      ["pointer"]   = { "fg", opts.hls.fzf.pointer },
      ["marker"]    = { "fg", opts.hls.fzf.marker },
      ["spinner"]   = { "fg", opts.hls.fzf.spinner },
      ["header"]    = { "fg", opts.hls.fzf.header },
      ["separator"] = { "fg", opts.hls.fzf.separator },
      ["scrollbar"] = { "fg", opts.hls.fzf.scrollbar }
    })
  end

  -- Adjust main fzf window treesitter settings
  -- Disabled unless the picker is TS enabled with `_treesitter=true`
  -- Unless `enabled=false` is specifically set `true` is asssumed
  if not opts._treesitter then opts.winopts.treesitter = nil end
  if not opts.winopts.treesitter or opts.winopts.treesitter.enabled == false then
    opts.winopts.treesitter = nil
  else
    assert(type(opts.winopts.treesitter) == "table")
    assert(not opts.fzf_colors or type(opts.fzf_colors) == "table")
    -- Unless the caller specifically disables `fzf_colors` fuzzy matching
    -- colors "hl,hl+" will be set to "-1:reverse" which sets the background
    -- color for matches to the corresponding original foreground color
    -- NOTE: `fzf_colors` inherited from `defaults.winopts.treesitter`
    if opts.winopts.treesitter.fzf_colors ~= false then
      opts.fzf_colors = vim.tbl_deep_extend("force",
        type(opts.fzf_colors) == "table" and opts.fzf_colors or {},
        M.defaults.winopts.treesitter.fzf_colors,
        type(opts.winopts.treesitter.fzf_colors) == "table"
        and opts.winopts.treesitter.fzf_colors or {})
    end
  end

  -- we need the original `cwd` with `autochdir=true` (#882)
  -- use `_cwd` to not interfere with supplied users' options
  -- as this can have unintended effects (e.g. in "buffers")
  -- NOTE: we now always get the original cwd as there are
  -- other user scenarios which need to use `opts._cwd`, for
  -- exmaple, using the "hide" profile and resuming fzf-lua
  -- from another tab after a `:tcd <dir>` (#1854)
  opts._cwd = uv.cwd()

  if opts.cwd and #opts.cwd > 0 then
    -- NOTE: on Windows, `expand` will replace all backslashes with forward slashes
    -- i.e. C:/Users -> c:\Users
    -- Also reduces double backslashes to a single backslash, we therefore double
    -- the backslashes prior to expanding (#1429)
    opts.cwd = libuv.expand(opts.cwd)
    if not uv.fs_stat(opts.cwd) then
      utils.warn(("Unable to access '%s', removing 'cwd' option."):format(opts.cwd))
      opts.cwd = nil
    else
      if not path.is_absolute(opts.cwd) then
        -- relative paths in cwd are inaccessible when using multiprocess
        -- as the external process have no awareness of our current working
        -- directory so we must convert to full path (#375)
        opts.cwd = path.join({ uv.cwd(), opts.cwd })
      elseif utils.__IS_WINDOWS and opts.cwd:sub(2) == ":" then
        -- TODO: upstream bug? on Windows: starting jobs with `cwd = C:` (without separator)
        -- ignores the cwd argument and starts the job in the current working directory
        opts.cwd = path.add_trailing(opts.cwd)
      end
    end
  end

  -- test for valid git_repo
  opts.git_icons = opts.git_icons and path.is_git_repo(opts, true)

  local executable = function(binary, fncerr, strerr)
    if binary and vim.fn.executable(binary) ~= 1 then
      fncerr(("'%s' is not a valid executable, %s"):format(binary, strerr))
      return false
    end
    return true
  end

  opts.fzf_bin = opts.fzf_bin or M.globals.fzf_bin
  opts.fzf_bin = opts.fzf_bin and libuv.expand(opts.fzf_bin) or nil
  if not opts.fzf_bin or
      not executable(opts.fzf_bin, utils.warn, "fallback to 'fzf'.") then
    -- default|fallback to fzf
    opts.fzf_bin = "fzf"
    -- try fzf plugin if fzf is not installed globally
    if vim.fn.executable(opts.fzf_bin) ~= 1 then
      local ok, fzf_plug = pcall(vim.api.nvim_call_function, "fzf#exec", {})
      if ok and fzf_plug then
        opts.fzf_bin = fzf_plug
      end
    end
    if not executable(opts.fzf_bin, utils.err,
          "aborting. Please make sure 'fzf' is in installed.") then
      return nil
    end
  end

  -- are we using skim?
  opts._is_skim = opts.fzf_bin:match("sk$") ~= nil

  -- enforce fzf minimum requirements
  vim.g.fzf_lua_fzf_version = nil
  if not opts._is_skim then
    local FZF_VERSION, rc, err = utils.fzf_version(opts)
    opts.__FZF_VERSION = FZF_VERSION
    vim.g.fzf_lua_fzf_version = FZF_VERSION
    if not opts.__FZF_VERSION then
      utils.err(string.format("'fzf --version' failed with error %s: %s", rc, err))
      return nil
    elseif not utils.has(opts, "fzf", { 0, 25 }) then
      utils.err(string.format("fzf version %s is lower than minimum (0.25), aborting.",
        utils.ver2str(opts.__FZF_VERSION)))
      return nil
    end
  else
    local SK_VERSION, rc, err = utils.sk_version(opts)
    opts.__SK_VERSION = SK_VERSION
    if not opts.__SK_VERSION then
      utils.err(string.format("'sk --version' failed with error %s: %s", rc, err))
      return nil
    end
  end

  if utils.has(opts, "fzf", { 0, 53 })
      -- `_multiline` is used to override `multiline` inherited from `defaults = {}`
      and opts.multiline and opts._multiline ~= false then
    -- If `multiline` was specified we add both "read0" & "print0" flags
    opts.fzf_opts["--read0"] = true
    opts.fzf_opts["--print0"] = true
    local gap = (tonumber(opts.multiline) or 1) - 1
    if gap > 0 then opts.fzf_opts["--gap"] = gap end
  else
    -- If not possible (fzf v<0.53|skim), nullify the option
    opts.multiline = nil
  end

  do
    -- Remove incompatible flags / values
    --   (1) `true` flags are removed entirely (regardless of value)
    --   (2) `string` flags are removed only if the values match
    --   (3) `table` flags are removed if the value is contained
    local bin, version, changelog = (function()
      if opts.__SK_VERSION then
        return "sk", opts.__SK_VERSION, {
          ["0.15.5"] = { fzf_opts = { ["--tmux"] = true } },
          ["0.53"] = { fzf_opts = { ["--inline-info"] = true } },
          -- All fzf flags not existing in skim
          ["all"] = {
            fzf_opts = {
              ["--scheme"]         = false,
              ["--gap"]            = false,
              ["--info"]           = false,
              ["--border"]         = false,
              ["--scrollbar"]      = false,
              ["--no-scrollbar"]   = false,
              ["--highlight-line"] = false,
            }
          },
        }
      else
        return "fzf", opts.__FZF_VERSION, {
          ["0.59"] = { fzf_opts = { ["--scheme"] = "path" } },
          ["0.56"] = { fzf_opts = { ["--gap"] = true } },
          ["0.54"] = {
            fzf_opts = {
              ["-wrap"]            = true,
              ["-wrap-sign"]       = true,
              ["--highlight-line"] = true,
            }
          },
          ["0.53"] = { fzf_opts = { ["--tmux"] = true } },
          ["0.52"] = { fzf_opts = { ["--highlight-line"] = true } },
          ["0.42"] = {
            fzf_opts = {
              ["--info"] = { "right", "inline-right" },
            }
          },
          ["0.39"] = { fzf_opts = { ["--track"] = true } },
          ["0.36"] = {
            fzf_opts = {
              ["--listen"]       = true,
              ["--scrollbar"]    = true,
              ["--no-scrollbar"] = true,
            }
          },
          ["0.35"] = {
            fzf_opts = {
              ["--border"]            = { "bold", "double" },
              ["--border-label"]      = true,
              ["--border-label-pos"]  = true,
              ["--preview-label"]     = true,
              ["--preview-label-pos"] = true,
            }
          },
          ["0.33"] = { fzf_opts = { ["--scheme"] = true } },
          ["0.30"] = { fzf_opts = { ["--ellipsis"] = true } },
          ["0.28"] = {
            fzf_opts = {
              ["--header-first"] = true,
              ["--scroll-off"]   = true,
            }
          },
          ["0.27"] = { fzf_opts = { ["--border"] = "none" } },
          -- All skim flags not existing in fzf
          ["all"] = {
            fzf_opts = {
              ["--inline-info"] = false,
            }
          },
        }
      end
    end)()
    local function warn(flag, val, min_ver)
      return utils.warn(string.format("Removed flag '%s%s', %s.",
        flag, type(val) == "string" and "=" .. val or "",
        not min_ver and string.format("not supported with %s", bin)
        or string.format("only supported with %s v%s (has=%s)",
          bin, utils.ver2str(min_ver), utils.ver2str(version))
      ))
    end
    for min_verstr, ver_data in pairs(changelog) do
      for flag, non_compat_value in pairs(ver_data.fzf_opts) do
        (function()
          local min_ver = utils.parse_verstr(min_verstr)
          local opt_value = opts.fzf_opts[flag]
          if not opt_value then return end
          non_compat_value = type(non_compat_value) == "string"
              and { non_compat_value } or non_compat_value
          if not min_ver or not utils.has(opts, bin, min_ver)
              and (non_compat_value == true or type(non_compat_value) == "table"
                and utils.tbl_contains(non_compat_value, opt_value))
          then
            if opts.compat_warn == true then
              warn(flag, opt_value, min_ver)
            end
            opts.fzf_opts[flag] = nil
          end
        end)()
      end
    end
  end

  -- Are we using fzf-tmux? if so get available columns
  opts._is_fzf_tmux = (function()
    if not vim.env.TMUX then return end
    local is_tmux =
        (opts.fzf_bin:match("fzf%-tmux$") or opts.fzf_bin:match("sk%-tmux$")) and 1
        -- fzf v0.53 added native tmux integration
        or utils.has(opts, "fzf", { 0, 53 }) and opts.fzf_opts["--tmux"] and 2
        -- skim v0.15.5 added native tmux integration
        or utils.has(opts, "sk", { 0, 15, 5 }) and opts.fzf_opts["--tmux"] and 2
    if is_tmux == 1 then
      -- backward compat when using the `fzf-tmux` script: prioritize fzf-tmux
      -- split pane flags over the popup flag `-p` from fzf-lua defaults (#865)
      if type(opts.fzf_tmux_opts) == "table" then
        for _, flag in ipairs({ "-u", "-d", "-l", "-r" }) do
          if opts.fzf_tmux_opts[flag] then
            opts.fzf_tmux_opts["-p"] = nil
          end
        end
      end
    end
    return is_tmux
  end)()

  -- refresh highlights if background/colorscheme changed (#1092)
  if not M.__HLS_STATE
      or M.__HLS_STATE.bg ~= vim.o.bg
      or M.__HLS_STATE.colorscheme ~= vim.g.colors_name then
    utils.setup_highlights()
  end

  -- Cache provider specific highlights so we don't call vim functions
  -- within a "fast event" (`vim.in_fast_event()`) and err with:
  -- E5560: vimL function must not be called in a lua loop callback
  for _, hl_opt in ipairs(opts._cached_hls or {}) do
    local hlgroup = opts.hls[hl_opt]
    assert(hlgroup ~= nil) -- must exist
    local _, escseq = utils.ansi_from_hl(hlgroup)
    utils.cache_ansi_escseq(hlgroup, escseq)
  end


  if opts.file_icons then
    -- refresh icons, does nothing if "vim.o.bg" didn't change
    if not devicons.load({
          plugin = opts.file_icons,
          icon_padding = opts.file_icon_padding,
          dir_icon = {
            icon = opts.dir_icon,
            color = utils.hexcol_from_hl(opts.hls.dir_icon, "fg")
          }
        })
    then
      -- Disable file_icons if requested package isn't available
      -- we set the default value to "1" but since it's the default
      -- don't display the warning unless the user specifically set
      -- file_icons to `true` or `mini|devicons`
      if not tonumber(opts.file_icons) then
        utils.warn(string.format("error loading '%s', disabling 'file_icons'.",
          opts.file_icons == "mini" and "mini.icons" or "nvim-web-devicons"))
      end
      opts.file_icons = nil
    end
    if opts.file_icons == "mini" then
      -- When using "mini.icons" process lines 1-by-1 in the luv callback as having
      -- to wait for all lines takes much longer due to the `vim.filetype.match` call
      -- which makes the UX appear laggy
      opts.process1 = opts.process1 == nil and true or opts.process1
      -- We also want to store the cached extensions/filenames in the main thread
      -- which we do in "make_entry.postprocess"
      opts.__mt_postprocess = opts.multiprocess
          and [[return require("fzf-lua.make_entry").postprocess]]
          -- NOTE: we don't need to update mini when running on main thread
          -- or require("fzf-lua.make_entry").postprocess
          or nil
    end
  end

  if type(opts.enrich) == "function" then
    opts = opts.enrich(opts)
  end

  -- mark as normalized
  opts._normalized = true

  return opts
end

M.bytecode = function(s, datatype)
  local keys = utils.strsplit(s, "%.")
  local iter = M
  for i = 1, #keys do
    iter = iter[keys[i]]
    if not iter then break end
    if i == #keys and type(iter) == datatype then
      -- Not sure if second argument 'true' is needed
      -- can't find any references for it other than
      -- it being used in packer.nvim
      return string.dump(iter, true)
    end
  end
end

M.set_action_helpstr = function(fn, helpstr)
  assert(type(fn) == "function")
  M._action_to_helpstr[fn] = helpstr
end

M.get_action_helpstr = function(fn)
  return M._action_to_helpstr[fn]
end

M._action_to_helpstr = {
  [actions.dummy_abort]          = "abort",
  [actions.file_edit]            = "file-edit",
  [actions.file_edit_or_qf]      = "file-edit-or-qf",
  [actions.file_split]           = "file-split",
  [actions.file_vsplit]          = "file-vsplit",
  [actions.file_tabedit]         = "file-tabedit",
  [actions.file_sel_to_qf]       = "file-selection-to-qf",
  [actions.file_sel_to_ll]       = "file-selection-to-loclist",
  [actions.file_switch]          = "file-switch",
  [actions.file_switch_or_edit]  = "file-switch-or-edit",
  -- Since default actions refactor these are just refs to
  -- their correspondent `file_xxx` equivalents
  -- [actions.buf_edit]            = "buffer-edit",
  -- [actions.buf_edit_or_qf]      = "buffer-edit-or-qf",
  -- [actions.buf_sel_to_qf]       = "buffer-selection-to-qf",
  -- [actions.buf_sel_to_ll]       = "buffer-selection-to-loclist",
  -- [actions.buf_split]           = "buffer-split",
  -- [actions.buf_vsplit]          = "buffer-vsplit",
  -- [actions.buf_tabedit]         = "buffer-tabedit",
  -- [actions.buf_switch]          = "buffer-switch",
  -- [actions.buf_switch_or_edit]  = "buffer-switch-or-edit",
  [actions.buf_del]              = "buffer-delete",
  [actions.run_builtin]          = "run-builtin",
  [actions.ex_run]               = "edit-cmd",
  [actions.ex_run_cr]            = "exec-cmd",
  [actions.exec_menu]            = "exec-menu",
  [actions.search]               = "edit-search",
  [actions.search_cr]            = "exec-search",
  [actions.goto_mark]            = "goto-mark",
  [actions.goto_jump]            = "goto-jump",
  [actions.keymap_apply]         = "keymap-apply",
  [actions.keymap_edit]          = "keymap-edit",
  [actions.keymap_split]         = "keymap-split",
  [actions.keymap_vsplit]        = "keymap-vsplit",
  [actions.keymap_tabedit]       = "keymap-tabedit",
  [actions.nvim_opt_edit_local]  = "nvim-opt-edit-local",
  [actions.nvim_opt_edit_global] = "nvim-opt-edit-global",
  [actions.spell_apply]          = "spell-apply",
  [actions.set_filetype]         = "set-filetype",
  [actions.packadd]              = "packadd",
  [actions.help]                 = "help-open",
  [actions.help_vert]            = "help-vertical",
  [actions.help_tab]             = "help-tab",
  [actions.man]                  = "man-open",
  [actions.man_vert]             = "man-vertical",
  [actions.man_tab]              = "man-tab",
  [actions.git_branch_add]       = "git-branch-add",
  [actions.git_branch_del]       = "git-branch-del",
  [actions.git_switch]           = "git-switch",
  [actions.git_checkout]         = "git-checkout",
  [actions.git_reset]            = "git-reset",
  [actions.git_stage]            = "git-stage",
  [actions.git_unstage]          = "git-unstage",
  [actions.git_stage_unstage]    = "git-stage-unstage",
  [actions.git_stash_pop]        = "git-stash-pop",
  [actions.git_stash_drop]       = "git-stash-drop",
  [actions.git_stash_apply]      = "git-stash-apply",
  [actions.git_buf_edit]         = "git-buffer-edit",
  [actions.git_buf_tabedit]      = "git-buffer-tabedit",
  [actions.git_buf_split]        = "git-buffer-split",
  [actions.git_buf_vsplit]       = "git-buffer-vsplit",
  [actions.git_goto_line]        = "git-goto-line",
  [actions.git_yank_commit]      = "git-yank-commit",
  [actions.arg_add]              = "arg-list-add",
  [actions.arg_del]              = "arg-list-delete",
  [actions.toggle_ignore]        = "toggle-ignore",
  [actions.toggle_hidden]        = "toggle-hidden",
  [actions.toggle_follow]        = "toggle-follow",
  [actions.grep_lgrep]           = "grep<->lgrep",
  [actions.sym_lsym]             = "sym<->lsym",
  [actions.tmux_buf_set_reg]     = "set-register",
  [actions.paste_register]       = "paste-register",
  [actions.set_qflist]           = "set-{qf|loc}list",
  [actions.apply_profile]        = "apply-profile",
  [actions.complete]             = "complete",
  [actions.dap_bp_del]           = "dap-bp-delete",
  [actions.colorscheme]          = "colorscheme-apply",
  [actions.cs_delete]            = "colorscheme-delete",
  [actions.cs_update]            = "colorscheme-update",
  [actions.toggle_bg]            = "toggle-background",
  [actions.cd]                   = "change-directory",
}

return M
