/**
 * Chat Switchboard - API Module
 * Handles communication with LLM backends
 */

const API = {
    /**
     * Fetch available models from endpoint
     */
    async fetchModels(endpoint, apiKey) {
        const response = await fetch(endpoint.replace(/\/$/, '') + '/models', {
            headers: {
                'Authorization': `Bearer ${apiKey}`,
                'Content-Type': 'application/json'
            }
        });
        
        if (!response.ok) {
            throw new Error(`API Error: ${response.status}`);
        }
        
        const data = await response.json();
        const models = data.data || data.models || data || [];
        
        return Array.isArray(models) 
            ? models.map(m => ({
                id: m.id || m.name || m,
                owned_by: m.owned_by || null
            })).sort((a, b) => a.id.localeCompare(b.id))
            : [];
    },

    /**
     * Send chat completion request
     */
    async sendMessage(settings, messages, onChunk = null) {
        const endpoint = settings.apiEndpoint.replace(/\/$/, '') + '/chat/completions';
        
        const controller = new AbortController();
        
        const response = await fetch(endpoint, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json',
                'Authorization': `Bearer ${settings.apiKey}`
            },
            body: JSON.stringify({
                model: settings.model,
                messages: messages.map(m => ({ role: m.role, content: m.content })),
                max_tokens: settings.maxTokens,
                temperature: settings.temperature,
                top_p: settings.topP,
                presence_penalty: settings.presencePenalty,
                stream: settings.stream
            }),
            signal: controller.signal
        });

        if (!response.ok) {
            const error = await response.text();
            throw new Error(`API Error: ${response.status} - ${error}`);
        }

        let content = '';

        if (settings.stream && onChunk) {
            const reader = response.body.getReader();
            const decoder = new TextDecoder();
            
            while (true) {
                const { done, value } = await reader.read();
                if (done) break;
                
                const chunk = decoder.decode(value);
                const lines = chunk.split('\n');
                
                for (const line of lines) {
                    if (line.startsWith('data: ')) {
                        const data = line.slice(6);
                        if (data === '[DONE]') continue;
                        
                        try {
                            const parsed = JSON.parse(data);
                            const delta = parsed.choices?.[0]?.delta?.content || '';
                            content += delta;
                            onChunk(content, delta);
                        } catch (e) {}
                    }
                }
            }
        } else {
            const data = await response.json();
            content = data.choices?.[0]?.message?.content || 'No response';
        }

        return { content, controller };
    }
};