dirge-agent 0.7.4

//! Provider client construction.
//!
//! Contains `create_client` — the 8-backend dispatch that builds
//! rig clients (OpenAI, Anthropic, Gemini, DeepSeek, GLM, Ollama,
//! OpenRouter, Custom). Extracted from `provider/mod.rs` to keep
//! the provider module focused on type definitions + agent
//! construction.

use std::collections::HashMap;

use rig::providers::{anthropic, gemini, ollama, openai, openrouter};

use crate::config::ProviderEntry;

use super::{AnyClient, ProviderKind, resolve_api_key, resolve_provider_info};

pub(crate) fn create_client(
    provider_name: &str,
    api_key: Option<&str>,
    providers: &HashMap<String, ProviderEntry>,
) -> anyhow::Result<AnyClient> {
    let info = resolve_provider_info(provider_name, providers).ok_or_else(|| {
        anyhow::anyhow!(
            "Unknown provider: {}. Supported providers: openrouter, openai, anthropic, gemini, deepseek, glm, ollama, custom",
            provider_name
        )
    })?;

    // Precedence: CLI `--api-key` > `entry.api_key` (literal or
    // `${VAR}`-expanded) > `entry.api_key_env` > default env var
    // for the kind > kind-specific fallback env vars.
    let key = match (api_key, info.api_key_literal.as_deref()) {
        (Some(k), _) if !k.is_empty() => k.to_string(),
        (_, Some(k)) if !k.is_empty() => k.to_string(),
        _ => resolve_api_key(info.kind, info.api_key_env.as_deref(), api_key)?,
    };

    let base_url = match info.kind {
        ProviderKind::DeepSeek => Some(
            std::env::var("DEEPSEEK_BASE_URL")
                .unwrap_or_else(|_| "https://api.deepseek.com/v1".to_string()),
        ),
        ProviderKind::Glm => Some(
            std::env::var("GLM_BASE_URL")
                .unwrap_or_else(|_| "https://open.bigmodel.cn/api/coding/paas/v4".to_string()),
        ),
        ProviderKind::Custom => info
            .base_url
            .or_else(|| std::env::var("CUSTOM_BASE_URL").ok()),
        _ => info.base_url,
    };

    match info.kind {
        ProviderKind::OpenAI => {
            let mut b = openai::CompletionsClient::builder().api_key(&key);
            if let Some(base_url) = &base_url {
                b = b.base_url(base_url);
            }
            Ok(AnyClient::OpenAI(b.build()?))
        }
        ProviderKind::Anthropic => {
            let mut b = anthropic::Client::builder().api_key(&key);
            if let Some(base_url) = &base_url {
                b = b.base_url(base_url);
            }
            Ok(AnyClient::Anthropic(b.build()?))
        }
        ProviderKind::Gemini => {
            let mut b = gemini::Client::builder().api_key(&key);
            if let Some(base_url) = &base_url {
                b = b.base_url(base_url);
            }
            Ok(AnyClient::Gemini(b.build()?))
        }
        ProviderKind::DeepSeek => {
            let b = openai::CompletionsClient::builder()
                .api_key(&key)
                .base_url(base_url.as_deref().unwrap_or("https://api.deepseek.com/v1"));
            Ok(AnyClient::DeepSeek(b.build()?))
        }
        ProviderKind::Glm => {
            let b = openai::CompletionsClient::builder().api_key(&key).base_url(
                base_url
                    .as_deref()
                    .unwrap_or("https://open.bigmodel.cn/api/coding/paas/v4"),
            );
            Ok(AnyClient::Glm(b.build()?))
        }
        ProviderKind::Ollama => {
            let key: ollama::OllamaApiKey = key.as_str().into();
            let mut b = ollama::Client::builder().api_key(key);
            if let Some(base_url) = &base_url {
                b = b.base_url(base_url);
            }
            Ok(AnyClient::Ollama(b.build()?))
        }
        ProviderKind::OpenRouter => {
            let mut b = openrouter::Client::builder().api_key(&key);
            if let Some(base_url) = &base_url {
                b = b.base_url(base_url);
            }
            Ok(AnyClient::OpenRouter(b.build()?))
        }
        ProviderKind::Custom => {
            let base_url = base_url.ok_or_else(|| {
                anyhow::anyhow!(
                    "CUSTOM_BASE_URL environment variable must be set for custom provider"
                )
            })?;
            let b = openai::CompletionsClient::builder()
                .api_key(&key)
                .base_url(&base_url);
            Ok(AnyClient::Custom(b.build()?))
        }
    }
}