chatbot1-12  Exercise 1: Every Configuration Problem At Once
==============================================================

ex1.py (save in the project root):

  # Exercise 1: find every configuration problem at once, then fix them one by one.
  from bot.crypto import generate_key
  from bot.settings import load_settings

  env = {"CHATBOT_ENV": "production", "CHATBOT_PROVIDER": "claude", "CHATBOT_PORT": "eighty",
         "CHATBOT_CONTENT_KEYS": "not-a-key", "CHATBOT_WEB_SECRET": "short", "SLACK_BOT_TOKEN": "xoxb-1"}


  def show(title):
      s = load_settings(env)
      print(f"{title}: {len(s.problems)} problem(s)")
      for p in s.problems:
          print("   -", p)


  show("as first written")
  env.update(CHATBOT_PORT="8000", CHATBOT_CONTENT_KEYS=generate_key(), CHATBOT_WEB_SECRET="w" * 40, CHATBOT_LOG_KEY="l" * 20,
             CHATBOT_ALLOWED_ORIGINS="https://chat.example.org")
  show("after fixing the first group")
  env.update(ANTHROPIC_API_KEY="sk-ant-example", CHATBOT_MODEL="example-model", SLACK_SIGNING_SECRET="s3cret")
  show("after fixing the rest")

Run with:  py ex1.py

Output:

  as first written: 8 problem(s)
     - ANTHROPIC_API_KEY is required for provider 'claude'
     - CHATBOT_MODEL is required: read the current model name from your provider's model list
     - CHATBOT_WEB_SECRET must be at least 32 characters in production
     - CHATBOT_LOG_KEY must be at least 16 characters in production
     - CHATBOT_ALLOWED_ORIGINS is required in production (for example https://chat.example.org)
     - CHATBOT_CONTENT_KEYS contains a value that is not a valid Fernet key
     - SLACK_BOT_TOKEN and SLACK_SIGNING_SECRET must be set together
     - CHATBOT_PORT must be a whole number
  after fixing the first group: 3 problem(s)
     - ANTHROPIC_API_KEY is required for provider 'claude'
     - CHATBOT_MODEL is required: read the current model name from your provider's model list
     - SLACK_BOT_TOKEN and SLACK_SIGNING_SECRET must be set together
  after fixing the rest: 0 problem(s)

Reading the result:
  - All eight problems appeared in the first pass, so one round of editing can fix them; a program that stopped at the first would have taken eight restarts.
  - The invalid port is reported rather than crashing with a traceback, and the content key is reported without being printed.
  - Slack needs its token AND its signing secret; setting one alone is reported as a pair problem.
  - The real provider needs both its key variable and a model name. The model name is never defaulted, because a name written into a course goes out of date.

WHY THIS WORKS AS AN ANSWER
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load_settings() never raises for a bad value; it appends to a list of problems and carries on with a harmless default so the later checks can still run. The caller decides what to do: --check prints them and exits with status 1, and a production start refuses to run. The same function is used for both, so what --check says is what the service would do.