local has_cmp, cmp = pcall(require, "cmp")
if not has_cmp then
   return
end

local has_job, Job = pcall(require, "plenary.job")
if not has_job then
   return
end

local source = {}
local defaults = {
  space_filter = "-",
  address_book = nil,
}

source.new = function()
   return setmetatable({}, { __index = source })
end

function source:is_available()
   return vim.bo.filetype == "mail"
end
function source:get_debug_name()
   return "abook"
end

function source:complete(params, callback)
   params.option = vim.tbl_deep_extend("keep", params.option, defaults)
   vim.validate(
      "params.option.space_filter",
      params.option.space_filter,
      { "string" }
   )

   local ctx = params.context

   if
      not (
         ctx.cursor_line:match("^To: ")
         or ctx.cursor_line:match("^Cc: ")
         or ctx.cursor_line:match("^Bcc: ")
      )
   then
      callback({})
      return
   end

   local query = ""
   local line = ctx.cursor_line
   local cursor = ctx.cursor.character
   for i = cursor, 1, -1 do
      local char = line:sub(i, i)
      if char == ":" or char == "," then
         query = line:sub(i + 2, cursor)
         break
      end
   end

  local abook_addressbook = os.getenv("ABOOK_ADDRESSBOOK")
  local abook_args = { "--mutt-query", query }
  if abook_addressbook then
    table.insert(abook_args, "-f")
    table.insert(abook_args, abook_addressbook)
  end

   Job
      :new({
         command = "abook",
         args = abook_args,
         on_exit = function(job, code)
            if code ~= 0 then
               return
            end

            local result = job:result()

            local items = {}
            for _, item in ipairs(result) do
               local item_parts = vim.split(item, "\t", { trimempty = true })
               local label = string.format(
                  "%s <%s>",
                  item_parts[2],
                  item_parts[1]
               ) or item_parts[1]
               table.insert(items, {
                  label = label,
                  filterText = label:gsub(" ", params.option.space_filter),
                  kind = cmp.lsp.CompletionItemKind.Text,
               })
            end

            callback({ items = items, isIncomplete = false })
         end,
      })
      :start()
end

return source