<?php
/**
 * WEVAL MIND Failover System
 * Gère la rotation automatique entre providers
 */

class HamidFailover {
    private $statusFile = "/tmp/hamid_provider_status.json";
    private $providers;
    private $config;
    
    // Priorité des providers (gratuit illimité → payant)
    private $priority = [
        "cerebras",      // #1 Gratuit illimité, 500ms
        "groq",          // #2 Gratuit 100k/jour, 1s
        "sambanova",     // #3 Gratuit, 2s
        "mistral",       // #4 Gratuit limité
        "cohere",        // #5 Gratuit limité
        "together",      // #6 Gratuit limité
        "fireworks",     // #7 Gratuit limité
        "deepseek",      // #9 Payant pas cher
        "claude",        // #10 Payant premium
        "openai",        // #11 Payant premium
        "ollama"         // #12 Local backup
    ];
    
    // Providers sans clé API
    private $noKeyProviders = ["ollama", "ollama-mini", "vllm", "lmstudio", "localai", "n8n"];
    
    public function __construct($providers, $config) {
        $this->providers = $providers;
        $this->config = $config;
    }
    
    public function getStatus() {
        if (!file_exists($this->statusFile)) return [];
        $status = json_decode(file_get_contents($this->statusFile), true) ?: [];
        // Nettoyer les vieux statuts (> 5 min)
        foreach ($status as $p => $s) {
            if (time() - ($s["time"] ?? 0) > 300) {
                unset($status[$p]);
            }
        }
        return $status;
    }
    
    public function markDown($provider, $error) {
        $status = $this->getStatus();
        $status[$provider] = ["down" => true, "error" => $error, "time" => time()];
        file_put_contents($this->statusFile, json_encode($status));
    }
    
    public function markUp($provider) {
        $status = $this->getStatus();
        unset($status[$provider]);
        file_put_contents($this->statusFile, json_encode($status));
    }
    
    public function isAvailable($provider) {
        // Vérifier si down
        $status = $this->getStatus();
        if (isset($status[$provider]["down"])) return false;
        
        // Vérifier si clé API configurée
        if (!in_array($provider, $this->noKeyProviders)) {
            $keyField = $provider . "_api_key";
            if ($provider == "claude") $keyField = "claude_api_key";
            if (empty($this->config[$keyField])) return false;
        }
        
        return true;
    }
    
    public function getNextProvider($currentProvider) {
        $idx = array_search($currentProvider, $this->priority);
        if ($idx === false) $idx = -1;
        
        for ($i = $idx + 1; $i < count($this->priority); $i++) {
            if ($this->isAvailable($this->priority[$i])) {
                return $this->priority[$i];
            }
        }
        
        // Fallback: retourner ollama (toujours dispo localement)
        return "ollama";
    }
    
    public function getBestProvider($requested = null) {
        // Si provider demandé est dispo, l'utiliser
        if ($requested && $this->isAvailable($requested)) {
            return $requested;
        }
        
        // Sinon, trouver le meilleur disponible
        foreach ($this->priority as $p) {
            if ($this->isAvailable($p)) {
                return $p;
            }
        }
        
        return "ollama"; // Dernier recours
    }
    
    public function callWithFailover($message, $history, $systemPrompt, $requestedProvider, $maxAttempts = 3) {
        $attempt = 0;
        $provider = $this->getBestProvider($requestedProvider);
        $originalProvider = $requestedProvider;
        $failoverUsed = ($provider !== $requestedProvider);
        $logs = [];
        
        while ($attempt < $maxAttempts) {
            $attempt++;
            $start = microtime(true);
            
            try {
                $result = $this->callProvider($provider, $message, $history, $systemPrompt);
                $duration = round((microtime(true) - $start) * 1000);
                
                if ($result['success']) {
                    $this->markUp($provider);
                    return [
                        'success' => true,
                        'response' => $result['response'],
                        'provider' => $provider,
                        'model' => $result['model'],
                        'duration' => $duration,
                        'failover_used' => $failoverUsed,
                        'original_provider' => $originalProvider,
                        'attempts' => $logs
                    ];
                } else {
                    $this->markDown($provider, $result['error']);
                    $logs[] = ['provider' => $provider, 'error' => $result['error'], 'time' => $duration];
                }
            } catch (Exception $e) {
                $duration = round((microtime(true) - $start) * 1000);
                $this->markDown($provider, $e->getMessage());
                $logs[] = ['provider' => $provider, 'error' => $e->getMessage(), 'time' => $duration];
            }
            
            // Passer au provider suivant
            $provider = $this->getNextProvider($provider);
            $failoverUsed = true;
        }
        
        return [
            'success' => false,
            'error' => 'Tous les providers ont échoué',
            'attempts' => $logs
        ];
    }
    
    private function callProvider($provider, $message, $history, $systemPrompt) {
        $cfg = $this->providers[$provider] ?? null;
        if (!$cfg) return ['success' => false, 'error' => 'Provider non configuré'];
        
        $ch = curl_init();
        $timeout = ($provider === 'ollama' || $provider === 'ollama-mini') ? 120 : 30;
        
        // Construire les messages
        $messages = [['role' => 'system', 'content' => $systemPrompt]];
        if (!empty($history)) {
            foreach ($history as $h) {
                $messages[] = ['role' => $h['role'], 'content' => $h['content']];
            }
        }
        $messages[] = ['role' => 'user', 'content' => $message];
        
        // Config spécifique Claude
        if ($provider === 'claude') {
            $claudeMessages = array_filter($messages, fn($m) => $m['role'] !== 'system');
            $claudeMessages = array_values($claudeMessages);
            
            $payload = [
                'model' => $cfg['model'],
                'max_tokens' => 4096,
                'system' => $systemPrompt,
                'messages' => $claudeMessages
            ];
            
            curl_setopt_array($ch, [
                CURLOPT_URL => $cfg['url'],
                CURLOPT_RETURNTRANSFER => true,
                CURLOPT_POST => true,
                CURLOPT_TIMEOUT => $timeout,
                CURLOPT_HTTPHEADER => [
                    'Content-Type: application/json',
                    'x-api-key: ' . $cfg['key'],
                    'anthropic-version: 2023-06-01'
                ],
                CURLOPT_POSTFIELDS => json_encode($payload)
            ]);
        } else {
            // OpenAI-compatible
            $payload = [
                'model' => $cfg['model'],
                'messages' => $messages,
                'max_tokens' => $cfg['max_tokens'] ?? 4096,
                'temperature' => 0.7
            ];
            
            $headers = ['Content-Type: application/json'];
            if (!empty($cfg['key'])) {
                $headers[] = 'Authorization: Bearer ' . $cfg['key'];
            }
            
            curl_setopt_array($ch, [
                CURLOPT_URL => $cfg['url'],
                CURLOPT_RETURNTRANSFER => true,
                CURLOPT_POST => true,
                CURLOPT_TIMEOUT => $timeout,
                CURLOPT_HTTPHEADER => $headers,
                CURLOPT_POSTFIELDS => json_encode($payload)
            ]);
        }
        
        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $curlError = curl_error($ch);
        curl_close($ch);
        
        if ($curlError) {
            return ['success' => false, 'error' => 'timeout'];
        }
        
        if ($httpCode >= 400) {
            $errMap = [429 => 'rate_limit', 402 => 'no_credits', 401 => 'invalid_key', 403 => 'forbidden'];
            return ['success' => false, 'error' => $errMap[$httpCode] ?? "http_$httpCode"];
        }
        
        $data = json_decode($response, true);
        
        // Extraire réponse
        if ($provider === 'claude') {
            $text = $data['content'][0]['text'] ?? '';
        } else {
            $text = $data['choices'][0]['message']['content'] ?? '';
        }
        
        if (empty($text)) {
            return ['success' => false, 'error' => 'empty_response'];
        }
        
        return [
            'success' => true,
            'response' => $text,
            'model' => $cfg['model']
        ];
    }
}