Update ai_providers_find() to handle NULL search_str safely by treating it
as an empty string, preventing a segfault in strdup() within autocomplete_complete().
Rename test_ai_providers_find_case_sensitive to test_ai_providers_find_case_insensitive
to reflect the new case-insensitive matching contract. Update all affected tests to
expect cycling behavior (NULL/empty returns first provider) and use auto_gchar for
automatic memory management.
Use `gchar` instead of `char` in ai_providers_find for consistency
Add an AI client module that integrates with OpenAI-compatible API
providers (OpenAI, Perplexity, and custom providers) to provide
AI-assisted responses within the profanity client.
The implementation includes:
- src/ai/ai_client.c/h: Core AI client with provider management,
session handling, and async HTTP request handling via libcurl.
Supports per-provider API keys stored in preferences, reference-
counted sessions, and conversation history tracking.
- src/ui/window.c/window_list.c: New AI window type (ProfAiWin) for
displaying AI conversations, with response streaming and error
display capabilities.
- Command integration: New `/ai` command (cmd_defs.c, cmd_funcs.c)
for creating sessions, sending prompts, and managing providers.
Provider autocomplete support in cmd_ac.c.
- Preferences integration: API keys for providers are persisted in
the preferences system (config/preferences.c).
- Unit tests: 472 lines of comprehensive tests covering provider
management, session lifecycle, JSON escaping, and autocomplete
(tests/unittests/test_ai_client.c).
Architecture decisions:
- Asynchronous design: HTTP requests run on a separate thread to
avoid blocking the main UI loop. Callbacks are invoked on the main
thread via direct function call (profanity uses ncurses, not GLib
main loop).
- Reference counting: Both AIProvider and AISession use ref counting
for safe shared ownership.
- Response size limit: 10MB cap on HTTP responses to prevent OOM.
