feat: AI Editor — toolbar avec menus dropdown, multi-provider (DeepSeek/OpenRouter/Gemini)

backend/ai.py

@@ -0,0 +1,253 @@
+"""ObsiGate AI — Multi-provider AI service for editor enhancement.
+
+Supports: DeepSeek, OpenRouter, Google Gemini.
+Configured via environment variables.
+"""
+
+import os
+import json
+import logging
+import httpx
+from typing import Optional, Literal
+
+logger = logging.getLogger("obsigate.ai")
+
+ProviderName = Literal["deepseek", "openrouter", "gemini"]
+
+# Provider configurations
+PROVIDERS = {
+    "deepseek": {
+        "api_key": os.getenv("DEEPSEEK_API_KEY", ""),
+        "base_url": "https://api.deepseek.com/v1",
+        "model": os.getenv("DEEPSEEK_MODEL", "deepseek-chat"),
+        "auth_header": "Bearer {api_key}",
+    },
+    "openrouter": {
+        "api_key": os.getenv("OPENROUTER_API_KEY", ""),
+        "base_url": "https://openrouter.ai/api/v1",
+        "model": os.getenv("OPENROUTER_MODEL", "openai/gpt-4o-mini"),
+        "auth_header": "Bearer {api_key}",
+    },
+    "gemini": {
+        "api_key": os.getenv("GEMINI_API_KEY", ""),
+        "base_url": "https://generativelanguage.googleapis.com/v1beta",
+        "model": os.getenv("GEMINI_MODEL", "gemini-2.0-flash"),
+        "auth_header": None,  # Uses query param ?key=
+    },
+}
+
+DEFAULT_PROVIDER: ProviderName = os.getenv("AI_DEFAULT_PROVIDER", "deepseek")  # type: ignore
+
+
+def _get_provider_config(provider: Optional[ProviderName] = None) -> dict:
+    """Get provider config, falling back to default if requested provider unavailable."""
+    p = provider or DEFAULT_PROVIDER
+    if p not in PROVIDERS:
+        p = DEFAULT_PROVIDER
+    cfg = PROVIDERS[p]
+    if not cfg["api_key"]:
+        # Try next available provider
+        for alt in PROVIDERS:
+            if PROVIDERS[alt]["api_key"]:
+                p = alt
+                cfg = PROVIDERS[alt]
+                break
+    return {"name": p, **cfg}
+
+
+async def _call_deepseek_openrouter(prompt: str, system: str, provider: Optional[ProviderName] = None,
+                                     temperature: float = 0.7, max_tokens: int = 2048) -> str:
+    """Call OpenAI-compatible API (DeepSeek, OpenRouter)."""
+    cfg = _get_provider_config(provider)
+    headers = {
+        "Authorization": cfg["auth_header"].format(api_key=cfg["api_key"]),
+        "Content-Type": "application/json",
+    }
+    payload = {
+        "model": cfg["model"],
+        "messages": [
+            {"role": "system", "content": system},
+            {"role": "user", "content": prompt},
+        ],
+        "temperature": temperature,
+        "max_tokens": max_tokens,
+    }
+    async with httpx.AsyncClient(timeout=60.0) as client:
+        resp = await client.post(
+            f"{cfg['base_url']}/chat/completions",
+            headers=headers,
+            json=payload,
+        )
+        resp.raise_for_status()
+        data = resp.json()
+        return data["choices"][0]["message"]["content"].strip()
+
+
+async def _call_gemini(prompt: str, system: str, temperature: float = 0.7, max_tokens: int = 2048) -> str:
+    """Call Google Gemini API."""
+    cfg = PROVIDERS["gemini"]
+    url = f"{cfg['base_url']}/models/{cfg['model']}:generateContent?key={cfg['api_key']}"
+    payload = {
+        "system_instruction": {"parts": [{"text": system}]},
+        "contents": [{"parts": [{"text": prompt}]}],
+        "generationConfig": {
+            "temperature": temperature,
+            "maxOutputTokens": max_tokens,
+        },
+    }
+    async with httpx.AsyncClient(timeout=60.0) as client:
+        resp = await client.post(url, json=payload)
+        resp.raise_for_status()
+        data = resp.json()
+        return data["candidates"][0]["content"]["parts"][0]["text"].strip()
+
+
+async def ai_complete(prompt: str, provider: Optional[ProviderName] = None) -> str:
+    """Generic AI completion. Routes to appropriate provider."""
+    cfg = _get_provider_config(provider)
+    if cfg["name"] == "gemini":
+        return await _call_gemini(prompt, "You are a helpful assistant.")
+    return await _call_deepseek_openrouter(prompt, "You are a helpful assistant.", provider)
+
+
+# ── Specialized AI actions ──
+
+SYSTEM_PROMPT = """You are an AI assistant integrated into ObsiGate, a knowledge management tool. 
+Your responses should be direct and concise. When editing text, return ONLY the modified text, 
+no explanations or markdown fences."""
+
+
+async def ai_improve_writing(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Improve writing quality while preserving meaning."""
+    return await _call_deepseek_openrouter(
+        f"Improve the following text. Fix grammar, clarity, and flow. Preserve the original language and meaning.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_fix_spelling(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Fix spelling and grammar errors."""
+    return await _call_deepseek_openrouter(
+        f"Fix all spelling and grammar errors in this text. Return only the corrected text.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.1,
+    )
+
+
+async def ai_make_shorter(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Make text more concise."""
+    return await _call_deepseek_openrouter(
+        f"Make this text shorter and more concise while preserving the key information.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_make_longer(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Expand text with more detail."""
+    return await _call_deepseek_openrouter(
+        f"Expand this text with more detail, examples, or explanation while keeping the same tone.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.7, max_tokens=4096,
+    )
+
+
+async def ai_simplify(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Simplify language."""
+    return await _call_deepseek_openrouter(
+        f"Simplify this text. Use clearer, more straightforward language. Avoid jargon.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_change_tone(text: str, tone: str, provider: Optional[ProviderName] = None) -> str:
+    """Change the tone of the text."""
+    return await _call_deepseek_openrouter(
+        f"Rewrite this text in a {tone} tone. Preserve the original meaning.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.5,
+    )
+
+
+async def ai_translate(text: str, target_lang: str, provider: Optional[ProviderName] = None) -> str:
+    """Translate text to target language."""
+    # Gemini is better at translation
+    if provider is None and PROVIDERS["gemini"]["api_key"]:
+        return await _call_gemini(
+            f"Translate the following text to {target_lang}. Return only the translation.\n\n{text}",
+            "You are a professional translator. Translate accurately and naturally.",
+            temperature=0.1,
+        )
+    return await _call_deepseek_openrouter(
+        f"Translate the following text to {target_lang}. Return only the translation.\n\n{text}",
+        "You are a professional translator. Translate accurately and naturally.",
+        provider, temperature=0.1,
+    )
+
+
+async def ai_explain(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Explain the selected text."""
+    return await _call_deepseek_openrouter(
+        f"Explain the following text clearly and concisely:\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_summarize(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Summarize the selected text."""
+    return await _call_deepseek_openrouter(
+        f"Summarize the following text concisely:\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_continue_writing(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Continue writing from the selected text."""
+    return await _call_deepseek_openrouter(
+        f"Continue writing from where this text leaves off. Match the style and tone:\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.7, max_tokens=4096,
+    )
+
+
+async def ai_custom_rewrite(text: str, instruction: str, provider: Optional[ProviderName] = None) -> str:
+    """Rewrite text based on a custom instruction."""
+    return await _call_deepseek_openrouter(
+        f"Rewrite the following text according to this instruction: {instruction}\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.5,
+    )
+
+
+async def ai_convert_to_list(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Convert paragraph text to a markdown list."""
+    return await _call_deepseek_openrouter(
+        f"Convert this text into a well-organized markdown bullet list. Extract key points.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.2,
+    )
+
+
+async def ai_convert_to_table(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Convert text to a markdown table."""
+    return await _call_deepseek_openrouter(
+        f"Convert this information into a markdown table. Choose appropriate columns.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.2,
+    )
+
+
+async def ai_generate_frontmatter(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Generate YAML frontmatter for a markdown document."""
+    return await _call_deepseek_openrouter(
+        f"Generate YAML frontmatter for this markdown document. Include: titre, tags (as list), catégorie, statut, date. Return ONLY the YAML between --- markers.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3,
+    )
+
+
+async def ai_inline_complete(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Inline completion — suggest continuation."""
+    return await _call_deepseek_openrouter(
+        f"Complete this text naturally. Return only the completion (just the new text, no repetition):\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3, max_tokens=512,
+    )
+
+
+async def ai_convert_to_canvas(text: str, provider: Optional[ProviderName] = None) -> str:
+    """Convert text to a Mermaid diagram or canvas representation."""
+    return await _call_deepseek_openrouter(
+        f"Convert this content into a Mermaid.js diagram if applicable, or a structured outline. Choose the best format.\n\n{text}",
+        SYSTEM_PROMPT, provider, temperature=0.3, max_tokens=4096,
+    )