---@class lazyvim.util.mini
local M = {}

---@alias Mini.ai.loc {line:number, col:number}
---@alias Mini.ai.region {from:Mini.ai.loc, to:Mini.ai.loc}

-- Mini.ai indent text object
-- For "a", it will include the non-whitespace line surrounding the indent block.
-- "a" is line-wise, "i" is character-wise.
function M.ai_indent(ai_type)
  local spaces = (" "):rep(vim.o.tabstop)
  local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
  local indents = {} ---@type {line: number, indent: number, text: string}[]

  for l, line in ipairs(lines) do
    if not line:find("^%s*$") then
      indents[#indents + 1] = { line = l, indent = #line:gsub("\t", spaces):match("^%s*"), text = line }
    end
  end

  local ret = {} ---@type (Mini.ai.region | {indent: number})[]

  for i = 1, #indents do
    if i == 1 or indents[i - 1].indent < indents[i].indent then
      local from, to = i, i
      for j = i + 1, #indents do
        if indents[j].indent < indents[i].indent then
          break
        end
        to = j
      end
      from = ai_type == "a" and from > 1 and from - 1 or from
      to = ai_type == "a" and to < #indents and to + 1 or to
      ret[#ret + 1] = {
        indent = indents[i].indent,
        from = { line = indents[from].line, col = ai_type == "a" and 1 or indents[from].indent + 1 },
        to = { line = indents[to].line, col = #indents[to].text },
      }
    end
  end

  return ret
end

-- taken from MiniExtra.gen_ai_spec.buffer
function M.ai_buffer(ai_type)
  local start_line, end_line = 1, vim.fn.line("$")
  if ai_type == "i" then
    -- Skip first and last blank lines for `i` textobject
    local first_nonblank, last_nonblank = vim.fn.nextnonblank(start_line), vim.fn.prevnonblank(end_line)
    -- Do nothing for buffer with all blanks
    if first_nonblank == 0 or last_nonblank == 0 then
      return { from = { line = start_line, col = 1 } }
    end
    start_line, end_line = first_nonblank, last_nonblank
  end

  local to_col = math.max(vim.fn.getline(end_line):len(), 1)
  return { from = { line = start_line, col = 1 }, to = { line = end_line, col = to_col } }
end

-- register all text objects with which-key
function M.ai_whichkey()
  local objects = {
    { " ", desc = "whitespace" },
    { '"', desc = 'balanced "' },
    { "'", desc = "balanced '" },
    { "(", desc = "balanced (" },
    { ")", desc = "balanced ) including white-space" },
    { "<", desc = "balanced <" },
    { ">", desc = "balanced > including white-space" },
    { "?", desc = "user prompt" },
    { "U", desc = "use/call without dot in name" },
    { "[", desc = "balanced [" },
    { "]", desc = "balanced ] including white-space" },
    { "_", desc = "underscore" },
    { "`", desc = "balanced `" },
    { "a", desc = "argument" },
    { "b", desc = "balanced )]}" },
    { "c", desc = "class" },
    { "d", desc = "digit(s)" },
    { "e", desc = "word in CamelCase & snake_case" },
    { "f", desc = "function" },
    { "g", desc = "entire file" },
    { "i", desc = "indent" },
    { "o", desc = "block, conditional, loop" },
    { "q", desc = "quote `\"'" },
    { "t", desc = "tag" },
    { "u", desc = "use/call function & method" },
    { "{", desc = "balanced {" },
    { "}", desc = "balanced } including white-space" },
  }

  local ret = { mode = { "o", "x" } }
  for prefix, name in pairs({
    i = "inside",
    a = "around",
    il = "last",
    ["in"] = "next",
    al = "last",
    an = "next",
  }) do
    ret[#ret + 1] = { prefix, group = name }
    for _, obj in ipairs(objects) do
      ret[#ret + 1] = { prefix .. obj[1], desc = obj.desc }
    end
  end
  require("which-key").add(ret, { notify = false })
end

---@param opts {skip_next: string, skip_ts: string[], skip_unbalanced: boolean, markdown: boolean}
function M.pairs(opts)
  local pairs = require("mini.pairs")
  pairs.setup(opts)
  local open = pairs.open
  pairs.open = function(pair, neigh_pattern)
    if vim.fn.getcmdline() ~= "" then
      return open(pair, neigh_pattern)
    end
    local o, c = pair:sub(1, 1), pair:sub(2, 2)
    local line = vim.api.nvim_get_current_line()
    local cursor = vim.api.nvim_win_get_cursor(0)
    local next = line:sub(cursor[2] + 1, cursor[2] + 1)
    local before = line:sub(1, cursor[2])
    if opts.markdown and o == "`" and vim.bo.filetype == "markdown" and before:match("^%s*``") then
      return "`\n```" .. vim.api.nvim_replace_termcodes("<up>", true, true, true)
    end
    if opts.skip_next and next ~= "" and next:match(opts.skip_next) then
      return o
    end
    if opts.skip_ts and #opts.skip_ts > 0 then
      local ok, captures = pcall(vim.treesitter.get_captures_at_pos, 0, cursor[1] - 1, math.max(cursor[2] - 1, 0))
      for _, capture in ipairs(ok and captures or {}) do
        if vim.tbl_contains(opts.skip_ts, capture.capture) then
          return o
        end
      end
    end
    if opts.skip_unbalanced and next == c and c ~= o then
      local _, count_open = line:gsub(vim.pesc(pair:sub(1, 1)), "")
      local _, count_close = line:gsub(vim.pesc(pair:sub(2, 2)), "")
      if count_close > count_open then
        return o
      end
    end
    return open(pair, neigh_pattern)
  end
end

return M