// LLM Client Implementation
let agentClient = null;
let currentModel = null;
let conversationHistory = [];

function initializeClient() {
    const apiKey = document.getElementById('apiKey').value;
    if (!apiKey) {
        showStatus("Please enter an API key", 'error');
        return;
    }
    
    agentClient = new ConversationalAgentClient(apiKey);
    agentClient.populateLLMModels()
        .then(models => {
            agentClient.updateModelSelect('modelSelect', models.find(m => m.includes("gemini-2.5")));
            currentModel = document.getElementById('modelSelect').value;
            showStatus(`Loaded ${models.length} models. Default: ${currentModel}`);
        })
        .catch(error => {
            showStatus(`Error fetching models: ${error.message}`, 'error');
        });
}

function addMessageEntry(direction, source, destination, content) {
    const flowDiv = document.getElementById('messageFlow');
    const timestamp = new Date().toLocaleTimeString();
    
    const entry = document.createElement('div');
    entry.className = `message-entry ${direction}`;
    entry.innerHTML = `
        <div class="message-header">
            <span>${source} → ${destination}</span>
            <span>${timestamp}</span>
        </div>
        <div style="white-space: pre-wrap;">${content}</div>
    `;
    
    flowDiv.appendChild(entry);
    flowDiv.scrollTop = flowDiv.scrollHeight;
}

// LLM Client Classes
class BaseAgentClient {
    constructor(apiKey, apiUrl = 'https://llm.synapse.thalescloud.io/v1/') {
        this.apiKey = apiKey;
        this.apiUrl = apiUrl;
        this.models = [];
        this.tools = [];
        this.maxCallsPerMinute = 4;
        this.callTimestamps = [];
    }

    setTools(tools) {
        this.tools = tools;
    }

    async fetchLLMModels() {
        if (!this.apiKey) throw new Error("API Key is not set.");
        console.log("Fetching models from:", this.apiUrl + 'models');
        
        try {
            const response = await fetch(this.apiUrl + 'models', {
                method: 'GET',
                headers: {
                    'Authorization': `Bearer ${this.apiKey}`
                }
            });
            
            if (!response.ok) {
                const errorText = await response.text();
                console.error("Fetch models error response:", errorText);
                throw new Error(`HTTP error! Status: ${response.status} - ${errorText}`);
            }
            
            const data = await response.json();
            console.log("Models fetched:", data.data);
            
            const filteredModels = data.data
                .map(model => model.id)
                .filter(id => !id.toLowerCase().includes('embed') && !id.toLowerCase().includes('image'));
            
            return filteredModels;
        } catch (error) {
            console.error('Error fetching LLM models:', error);
            throw new Error(`Failed to fetch models: ${error.message}`);
        }
    }
    
    async populateLLMModels(defaultModel = "gemini-2.5-pro-exp-03-25") {
        try {
            const modelList = await this.fetchLLMModels();
            
            const sortedModels = modelList.sort((a, b) => {
                if (a === defaultModel) return -1;
                if (b === defaultModel) return 1;
                return a.localeCompare(b);
            });
            
            const finalModels = [];
            
            if (sortedModels.includes(defaultModel)) {
                finalModels.push(defaultModel);
                sortedModels.forEach(model => {
                    if (model !== defaultModel) finalModels.push(model);
                });
            } else {
                finalModels.push(defaultModel);
                finalModels.push(...sortedModels);
            }
            
            this.models = finalModels;
            console.log("Populated models:", this.models);
            return this.models;
        } catch (error) {
            console.error("Error populating models:", error);
            this.models = [defaultModel];
            throw error;
        }
    }
    
    updateModelSelect(elementId = 'modelSelect', selectedModel = null) {
        const select = document.getElementById(elementId);
        if (!select) {
            console.warn(`Element ID ${elementId} not found.`);
            return;
        }
        
        const currentSelection = selectedModel || select.value || this.models[0];
        select.innerHTML = '';
        
        if (this.models.length === 0 || (this.models.length === 1 && this.models[0] === "gemini-2.5-pro-exp-03-25" && !this.apiKey)) {
            const option = document.createElement('option');
            option.value = "";
            option.textContent = "-- Fetch models first --";
            option.disabled = true;
            select.appendChild(option);
            return;
        }
        
        this.models.forEach(model => {
            const option = document.createElement('option');
            option.value = model;
            option.textContent = model;
            if (model === currentSelection) option.selected = true;
            select.appendChild(option);
        });
        
        if (!select.value && this.models.length > 0) select.value = this.models[0];
    }
    
    async rateLimitWait() {
        const currentTime = Date.now();
        this.callTimestamps = this.callTimestamps.filter(ts => currentTime - ts <= 60000);
        
        if (this.callTimestamps.length >= this.maxCallsPerMinute) {
            const waitTime = 60000 - (currentTime - this.callTimestamps[0]);
            const waitSeconds = Math.ceil(waitTime / 1000);
            const waitMessage = `Rate limit (${this.maxCallsPerMinute}/min) reached. Waiting ${waitSeconds}s...`;
            
            console.log(waitMessage);
            showStatus(waitMessage, 'warn');
            
            await new Promise(resolve => setTimeout(resolve, waitTime + 100));
            
            showStatus('Resuming after rate limit wait...', 'info');
            this.callTimestamps = this.callTimestamps.filter(ts => Date.now() - ts <= 60000);
        }
    }
    
    async callAgent(model, messages, tools = null) {
        await this.rateLimitWait();
        const startTime = Date.now();
        console.log("Calling Agent:", model);
        
        let body = {
            model: model,
            messages: messages
        }

        body.tools = tools;

        try {
            const response = await fetch(this.apiUrl + 'chat/completions', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${this.apiKey}`
                },
                body: JSON.stringify(body)
            });
            
            const endTime = Date.now();
            this.callTimestamps.push(endTime);
            console.log(`API call took ${endTime - startTime} ms`);
            
            if (!response.ok) {
                const errorData = await response.json().catch(() => ({ error: { message: response.statusText } }));
                console.error("API Error:", errorData);
                throw new Error(errorData.error?.message || `API failed: ${response.status}`);
            }
            
            const data = await response.json();
            if (!data.choices || !data.choices[0]?.message) throw new Error("Invalid API response structure");
            
            console.log("API Response received.");
            return data.choices[0].message;
        } catch (error) {
            this.callTimestamps.push(Date.now());
            console.error('Error calling agent:', error);
            throw error;
        }
    }
    
    setMaxCallsPerMinute(value) {
        const parsedValue = parseInt(value, 10);
        if (!isNaN(parsedValue) && parsedValue > 0) {
            console.log(`Max calls/min set to: ${parsedValue}`);
            this.maxCallsPerMinute = parsedValue;
            return true;
        }
        console.warn(`Invalid max calls/min: ${value}`);
        return false;
    }
}

class ConversationalAgentClient extends BaseAgentClient {
    constructor(apiKey, apiUrl = 'https://llm.synapse.thalescloud.io/v1/') {
        super(apiKey, apiUrl);
    }
    
    async call(model, userPrompt, conversationHistory = [], tools) {
        const messages = userPrompt ? [
            ...conversationHistory,
            { role: 'user', content: userPrompt }
        ] : [
            ...conversationHistory
        ];
        
        const assistantResponse = await super.callAgent(model, messages, tools);
        
        const updatedHistory = userPrompt ? [
            ...conversationHistory,
            { role: 'user', content: userPrompt },
            { role: assistantResponse.role, content: assistantResponse.content }
        ] : [
            ...conversationHistory,
            { role: assistantResponse.role, content: assistantResponse.content }
        ];
        
        return { 
            response: assistantResponse, 
            history: updatedHistory 
        };
    }
}

// Model selection change handler
document.getElementById('modelSelect').addEventListener('change', function() {
    currentModel = this.value;
    showStatus(`Model changed to: ${currentModel}`);
});