local Pos = require 'u.pos'

---@class u.Extmark
---@field bufnr integer
---@field id integer
---@field nsid integer
local Extmark = {}
Extmark.__index = Extmark

--- @param bufnr integer
--- @param nsid integer
--- @param id integer
function Extmark.new(bufnr, nsid, id)
  return setmetatable({
    bufnr = bufnr,
    nsid = nsid,
    id = id,
  }, Extmark)
end

--- @param range u.Range
--- @param nsid integer
function Extmark.from_range(range, nsid)
  local r = range:to_charwise()
  local stop = r.stop or r.start
  local end_row = stop.lnum - 1
  local end_col = stop.col
  if range.mode == 'V' then
    end_row = end_row + 1
    end_col = 0
  end
  local id = vim.api.nvim_buf_set_extmark(r.start.bufnr, nsid, r.start.lnum - 1, r.start.col - 1, {
    right_gravity = false,
    end_right_gravity = true,
    end_row = end_row,
    end_col = end_col,
  })
  return Extmark.new(r.start.bufnr, nsid, id)
end

function Extmark:range()
  local Range = require 'u.range'

  local raw_extmark =
    vim.api.nvim_buf_get_extmark_by_id(self.bufnr, self.nsid, self.id, { details = true })
  local start_row0, start_col0, details = unpack(raw_extmark)

  --- @type u.Pos
  local start = Pos.from00(self.bufnr, start_row0, start_col0)
  --- @type u.Pos?
  local stop = details
    and details.end_row
    and details.end_col
    and Pos.from01(self.bufnr, details.end_row, details.end_col)

  local n_buf_lines = vim.api.nvim_buf_line_count(self.bufnr)
  if stop and stop.lnum > n_buf_lines then
    stop.lnum = n_buf_lines
    stop = stop:eol()
  end
  if stop and stop.col == 0 then
    stop.col = 1
    stop = stop:next(-1)
  end

  return Range.new(start, stop, 'v')
end

function Extmark:delete() vim.api.nvim_buf_del_extmark(self.bufnr, self.nsid, self.id) end

return Extmark