"""Patch backend llm_params.py: force OpenRouter as the LiteLLM provider.

Root cause: the openai/-prefixed (and deepseek/) model routing returns only
``api_base`` + ``api_key``. LiteLLM resolves the provider from the model
string's org prefix, so for models whose org is NOT a recognized LiteLLM
provider (upstage/, nvidia/, liquid/, meta-llama/, google/, poolside/,
inclusionai/, ...) it raises "LLM Provider NOT provided" even though
``api_base`` points at OpenRouter. Only orgs that happen to match a real
LiteLLM provider (e.g. tencent/) worked by luck.

Fix: add ``custom_llm_provider: "openrouter"`` to both OpenRouter routing
branches so LiteLLM always uses the OpenRouter OpenAI-compatible client.

This runs AFTER patch_models.py (which may already have inserted the routing
blocks); it is idempotent.
"""

import ast
import os

FILE = "/app/agent/core/llm_params.py"

with open(FILE) as f:
    c = f.read()

before = c

# --- 1. openai/ branch (unique via or_model line) ---
openai_old = (
    '        or_model = normalized_model[len("openai/"):]\n'
    '        return {\n'
    '            "model": or_model,\n'
    '            "api_base": "https://openrouter.ai/api/v1",\n'
    '            "api_key": os.environ.get("OPENROUTER_API_KEY") or api_key or "",\n'
    '        }\n'
)
openai_new = (
    '        or_model = normalized_model[len("openai/"):]\n'
    '        return {\n'
    '            "model": or_model,\n'
    '            "api_base": "https://openrouter.ai/api/v1",\n'
    '            "api_key": os.environ.get("OPENROUTER_API_KEY") or api_key or "",\n'
    '            "custom_llm_provider": "openrouter",\n'
    '        }\n'
)

# --- 2. deepseek/ branch (unique via normalized_model on its own line) ---
deepseek_old = (
    '    if normalized_model.startswith("deepseek/"):\n'
    '        return {\n'
    '            "model": normalized_model,\n'
    '            "api_base": "https://openrouter.ai/api/v1",\n'
    '            "api_key": os.environ.get("OPENROUTER_API_KEY") or api_key or "",\n'
    '        }\n'
)
deepseek_new = (
    '    if normalized_model.startswith("deepseek/"):\n'
    '        return {\n'
    '            "model": normalized_model,\n'
    '            "api_base": "https://openrouter.ai/api/v1",\n'
    '            "api_key": os.environ.get("OPENROUTER_API_KEY") or api_key or "",\n'
    '            "custom_llm_provider": "openrouter",\n'
    '        }\n'
)

if 'custom_llm_provider' in c:
    print("OK: llm_params.py already contains custom_llm_provider (idempotent)")
else:
    n1 = c.count(openai_old)
    n2 = c.count(deepseek_old)
    if n1 == 1:
        c = c.replace(openai_old, openai_new)
        print("OK: openai/ branch -> custom_llm_provider='openrouter'")
    else:
        print(f"WARN: openai/ branch match count = {n1} (expected 1)")
    if n2 == 1:
        c = c.replace(deepseek_old, deepseek_new)
        print("OK: deepseek/ branch -> custom_llm_provider='openrouter'")
    else:
        print(f"WARN: deepseek/ branch match count = {n2} (expected 1)")

    if c != before:
        with open(FILE, "w") as f:
            f.write(c)
        try:
            ast.parse(c)
            print("OK: llm_params.py written & syntax valid")
        except SyntaxError as e:
            print(f"FAIL: llm_params.py syntax error: {e}")
            raise
    else:
        print("WARN: no changes applied")