harn-stdlib 0.10.124

import { chat_session } from "std/llm/chat_session"

/**
 * `harn chat` — start an interactive chat session with the live model.
 *
 * The loop itself lives in `std/llm/chat_session` so it can be driven by a
 * test, and by any other surface that wants the same conversation. This script
 * only turns the dispatch shim's environment into that module's config.
 *
 * Inputs (from the dispatch shim in crates/harn-cli/src/commands/chat.rs):
 *   HARN_CHAT_PROVIDER — resolved provider, or empty to let the catalog route
 *   HARN_CHAT_MODEL    — resolved model id or alias
 *   HARN_CHAT_LABEL    — display name for the banner (alias when there is one)
 *   HARN_CHAT_ENDPOINT — resolved endpoint, named in the banner
 *   HARN_CHAT_SYSTEM   — optional system prompt for the session
 *   HARN_CHAT_STATS    — "off" | "compact" | "verbose"
 */
fn __trimmed_env(env: HarnessEnv, key: string) {
  const value = trim(env.get_or(key, ""))
  if value == "" {
    return nil
  }
  return value
}

fn main(harness: Harness) -> int {
  const env = harness.env
  // Each key is added only when the shim set it: `ChatSessionConfig`'s
  // optional fields mean "the key may be absent", so handing one an explicit
  // nil is not the same as leaving it out.
  let config = {}
  const provider = __trimmed_env(env, "HARN_CHAT_PROVIDER")
  if provider != nil {
    config = config + {provider: provider}
  }
  const model = __trimmed_env(env, "HARN_CHAT_MODEL")
  if model != nil {
    config = config + {model: model}
  }
  const label = __trimmed_env(env, "HARN_CHAT_LABEL") ?? model
  if label != nil {
    config = config + {label: label}
  }
  const endpoint = __trimmed_env(env, "HARN_CHAT_ENDPOINT")
  if endpoint != nil {
    config = config + {endpoint: endpoint}
  }
  const system = __trimmed_env(env, "HARN_CHAT_SYSTEM")
  if system != nil {
    config = config + {system: system}
  }
  const stats = __trimmed_env(env, "HARN_CHAT_STATS")
  if stats != nil {
    config = config + {stats: stats}
  }
  return chat_session(harness, config)
}