local handler = require("chatgpt_nvim.handler")
local robust_lsp = require("chatgpt_nvim.tools.lsp_robust_diagnostics")

local M = {}

-- Enhanced search_and_replace to track if a string was found. We use Lua’s gsub return value 
-- (updatedString, replacementCount) to see if any replacements occurred.
local function search_and_replace(original, replacements)
  local updated = original
  local info_msgs = {}

  for _, r in ipairs(replacements) do
    local search_str = r.search or ""
    local replace_str = r.replace or ""

    local replacement_count = 0
    updated, replacement_count = updated:gsub(search_str, replace_str)

    -- If the string was not found, append an info message
    if replacement_count == 0 then
      table.insert(info_msgs, string.format(
        "[replace_in_file Info] The string '%s' was NOT found in the file and was not replaced.",
        search_str
      ))
    else
      table.insert(info_msgs, string.format(
        "[replace_in_file Info] The string '%s' was replaced %d time(s).",
        search_str,
        replacement_count
      ))
    end
  end

  return updated, table.concat(info_msgs, "\n")
end

M.run = function(tool_call, conf, prompt_user_tool_accept, is_subpath, read_file)
  local path = tool_call.path
  local replacements = tool_call.replacements or {}

  if not path or #replacements == 0 then
    return "[replace_in_file] Missing 'path' or 'replacements'."
  end
  local root = vim.fn.getcwd()

  if not is_subpath(root, path) then
    return string.format("Tool [replace_in_file for '%s'] REJECTED. Path outside project root.", path)
  end

  local orig_data = read_file(path)
  if not orig_data then
    return string.format("[replace_in_file for '%s'] FAILED. Could not read file.", path)
  end

  -- Now we get not only the updated data but also info messages about replacements
  local updated_data, info_messages = search_and_replace(orig_data, replacements)
  handler.write_file(path, updated_data, conf)

  local msg = {}
  msg[#msg+1] = string.format("[replace_in_file for '%s'] Result:\nThe content was successfully saved to %s.", path, path)
  msg[#msg+1] = "\nHere is the full, updated content of the file that was saved:\n"
  msg[#msg+1] = string.format("<final_file_content path=\"%s\">\n%s\n</final_file_content>", path, updated_data)
  msg[#msg+1] = "\nIMPORTANT: For any future changes to this file, use the final_file_content shown above as your reference.\n"

  -- If there are any info messages (strings not found, etc.), include them
  if info_messages and info_messages ~= "" then
    msg[#msg+1] = "\nAdditional info about the replacement operation:\n" .. info_messages .. "\n"
  end

  if conf.auto_lint then
    local diag_str = robust_lsp.lsp_check_file_content(path, updated_data, 3000)
    msg[#msg+1] = "\n" .. diag_str
  end

  return table.concat(msg, "")
end

return M