---@class snacks.picker.config
local M = {}

--- Source aliases
M.alias = {
  live_grep = "grep",
  find_files = "files",
  git_commits = "git_log",
  git_bcommits = "git_log_file",
  oldfiles = "recent",
}

local defaults ---@type snacks.picker.Config?

--- Fixes keys before merging configs for correctly resolving keymaps.
--- For example: <c-s> -> <C-S>
---@param opts? snacks.picker.Config
function M.fix_keys(opts)
  opts = opts or {}
  -- fix keys in sources
  for _, source in pairs(opts.sources or {}) do
    M.fix_keys(source)
  end
  if not opts.win then
    return opts
  end
  -- fix keys in wins
  for _, win in pairs(opts.win) do
    ---@cast win snacks.win.Config
    if win.keys then
      local keys = vim.tbl_keys(win.keys) ---@type string[]
      for _, key in ipairs(keys) do
        local norm = Snacks.util.normkey(key)
        if key ~= norm then
          win.keys[norm], win.keys[key] = win.keys[key], nil
        end
      end
    end
  end
  return opts
end

---@param opts? snacks.picker.Config
function M.get(opts)
  M.setup()
  opts = M.fix_keys(opts)

  -- Setup defaults
  if not defaults then
    defaults = require("snacks.picker.config.defaults").defaults
    defaults.sources = require("snacks.picker.config.sources")
    defaults.layouts = require("snacks.picker.config.layouts")
    M.fix_keys(defaults)
  end

  local user = M.fix_keys(Snacks.config.picker or {})
  opts.source = M.alias[opts.source] or opts.source

  -- Prepare config
  local global = Snacks.config.get("picker", defaults, opts) -- defaults + global user config
  local source = opts.source and global.sources[opts.source] or {}
  ---@type snacks.picker.Config[]
  local todo = {
    vim.deepcopy(defaults),
    vim.deepcopy(user),
    vim.deepcopy(source),
    opts,
  }

  -- Merge the confirm action into the actions table
  for _, t in ipairs(todo) do
    if t.confirm then
      t.actions = t.actions or {}
      t.actions.confirm = t.confirm
    end
  end

  -- Merge the configs
  return Snacks.config.merge(unpack(todo))
---@param opts snacks.picker.Config
function M.format(opts)
  local ret = type(opts.format) == "string" and Snacks.picker.format[opts.format]
    or opts.format
    or Snacks.picker.format.file
  ---@cast ret snacks.picker.format
  return ret
end

---@param opts snacks.picker.Config
function M.preview(opts)
  local preview = opts.preview or Snacks.picker.preview.file
  preview = type(preview) == "string" and Snacks.picker.preview[preview] or preview
  ---@cast preview snacks.picker.preview
  return preview
end

--- Resolve the layout configuration
---@param opts snacks.picker.Config|string
function M.layout(opts)
  if type(opts) == "string" then
    opts = M.get({ layout = { preset = opts } })
  end

  -- Resolve the layout configuration
  local layout = M.resolve(opts.layout or {}, opts.source)
  layout = type(layout) == "string" and { preset = layout } or layout
  ---@cast layout snacks.picker.layout.Config
  if layout.layout and layout.layout[1] then
    return layout
  end

  -- Resolve the preset
  local preset = M.resolve(layout.preset or "custom", opts.source)
  ---@type snacks.picker.layout.Config
  local ret = vim.deepcopy(opts.layouts and opts.layouts[preset] or {})

  -- Merge and return the layout
  return Snacks.config.merge(ret, layout)
end

---@generic T
---@generic A
---@param v (fun(...:A):T)|unknown
---@param ... A
---@return T
function M.resolve(v, ...)
  return type(v) == "function" and v(...) or v
end

--- Get the finder
---@param finder string|snacks.picker.finder|snacks.picker.finder.multi
---@return snacks.picker.finder
function M.finder(finder)
  local nop = function()
    Snacks.notify.error("Finder not found:\n```lua\n" .. vim.inspect(finder) .. "\n```", { title = "Snacks Picker" })
  end
  if not finder or type(finder) == "function" then
    return finder
  end
  if type(finder) == "table" then
    ---@cast finder snacks.picker.finder.multi
    ---@type snacks.picker.finder[]
    local finders = vim.tbl_map(function(f)
      return M.finder(f)
    end, finder)
    return require("snacks.picker.core.finder").multi(finders)
  end
  ---@cast finder string
  local mod, fn = finder:match("^(.-)_(.+)$")
  if not (mod and fn) then
    mod, fn = finder, finder
  end
  local ok, ret = pcall(function()
    return require("snacks.picker.source." .. mod)[fn]
  end)
  return ok and ret or nop
end

local did_setup = false
function M.setup()
  if did_setup then
    return
  end
  did_setup = true
  require("snacks.picker.config.highlights")
  for source in pairs(Snacks.picker.config.get().sources) do
    M.wrap(source)
  end
  --- Automatically wrap new sources added after setup
  setmetatable(require("snacks.picker.config.sources"), {
    __newindex = function(t, k, v)
      rawset(t, k, v)
      M.wrap(k)
    end,
  })
end

---@param source string
---@param opts? {check?: boolean}
function M.wrap(source, opts)
  if opts and opts.check then
    local config = M.get()
    if not config.sources[source] then
      return
    end
  end
  ---@type fun(opts: snacks.picker.Config): snacks.Picker
  local ret = function(_opts)
    return Snacks.picker.pick(source, _opts)
  end
  ---@diagnostic disable-next-line: no-unknown
  Snacks.picker[source] = ret
  return ret
end

return M