/**
 *  Chahuadev Framework - Context Manager Module
 * Pipeline Context Object Management & Data Flow Tracking
 * 
 *  Chahua Development Thailand
 *  CEO: Saharath C.
 *  www.chahuadev.com
 */

const crypto = require('crypto');

class ContextManager {
    constructor() {
        this.contexts = new Map(); // Store active contexts
        console.log(' Context Manager initialized');
    }

    /**
     * Create new pipeline context
     * @param {string} pipelineType - Type of pipeline (e.g., 'execution', 'api', 'validation')
     * @param {Object} initialData - Initial request data
     * @returns {Object} Pipeline context object
     */
    create(pipelineType = 'execution', initialData = {}) {
        const pipelineId = this.generatePipelineId();
        const timestamp = new Date().toISOString();

        const context = {
            // Pipeline identification
            pipelineId: pipelineId,
            pipelineType: pipelineType,
            timestamp: timestamp,
            
            // Request information
            request: {
                command: initialData.command || '',
                originalData: initialData || {},
                parameters: this.parseParameters(initialData),
                source: initialData.source || 'unknown'
            },

            // System information (will be populated by system-detector)
            systemInfo: {
                detectedType: null,
                projectPath: null,
                strategy: null,
                dependencies: [],
                environment: process.env.NODE_ENV || 'development'
            },

            // Security context
            security: {
                keyHash: null,
                permissionLevel: 'basic',
                userSession: null,
                securityChecks: [],
                validatedAt: null
            },

            // Execution tracking
            execution: {
                strategy: null,
                startTime: null,
                endTime: null,
                status: 'pending', // 'pending', 'running', 'completed', 'failed'
                exitCode: null,
                output: null
            },

            // Step tracking
            steps: [],

            // Performance metrics
            performance: {
                totalTime: null,
                memoryUsage: process.memoryUsage(),
                cacheHit: false,
                stepTimings: {}
            },

            // Error tracking
            error: null,

            // Metadata
            metadata: {
                createdAt: timestamp,
                updatedAt: timestamp,
                version: '1.0.0',
                framework: 'chahuadev'
            }
        };

        // Store context for tracking
        this.contexts.set(pipelineId, context);
        console.log(` Context created: ${pipelineId} (${pipelineType})`);
        
        return context;
    }

    /**
     * Add step result to context
     * @param {Object} context - Pipeline context
     * @param {string} stepName - Name of the step
     * @param {string} status - Step status ('started', 'completed', 'failed')
     * @param {*} result - Step result data
     * @returns {Object} Updated context
     */
    addStep(context, stepName, status, result = null) {
        if (!context || !context.pipelineId) {
            throw new Error('Invalid context provided');
        }

        const step = {
            stepName: stepName,
            timestamp: new Date().toISOString(),
            status: status,
            result: result,
            duration: null
        };

        // Calculate duration if completing a step
        if (status === 'completed' || status === 'failed') {
            const startStep = context.steps.find(s => 
                s.stepName === stepName && s.status === 'started'
            );
            if (startStep) {
                step.duration = Date.now() - new Date(startStep.timestamp).getTime();
                context.performance.stepTimings[stepName] = step.duration;
            }
        }

        context.steps.push(step);
        context.metadata.updatedAt = new Date().toISOString();

        console.log(` Step added: ${stepName} (${status}) to ${context.pipelineId}`);
        return context;
    }

    /**
     * Update context security information
     * @param {Object} context - Pipeline context
     * @param {Object} securityData - Security validation data
     * @returns {Object} Updated context
     */
    updateSecurity(context, securityData) {
        if (!context || !context.pipelineId) {
            throw new Error('Invalid context provided');
        }

        context.security = {
            ...context.security,
            ...securityData,
            validatedAt: new Date().toISOString()
        };

        context.metadata.updatedAt = new Date().toISOString();
        console.log(` Security updated for: ${context.pipelineId}`);
        
        return context;
    }

    /**
     * Update system information
     * @param {Object} context - Pipeline context
     * @param {Object} systemData - System detection data
     * @returns {Object} Updated context
     */
    updateSystemInfo(context, systemData) {
        if (!context || !context.pipelineId) {
            throw new Error('Invalid context provided');
        }

        context.systemInfo = {
            ...context.systemInfo,
            ...systemData
        };

        context.metadata.updatedAt = new Date().toISOString();
        console.log(` System info updated for: ${context.pipelineId}`);
        
        return context;
    }

    /**
     * Update execution status
     * @param {Object} context - Pipeline context
     * @param {string} status - Execution status
     * @param {*} output - Execution output
     * @param {number} exitCode - Exit code
     * @returns {Object} Updated context
     */
    updateExecution(context, status, output = null, exitCode = null) {
        if (!context || !context.pipelineId) {
            throw new Error('Invalid context provided');
        }

        // Set start time when execution begins
        if (status === 'running' && !context.execution.startTime) {
            context.execution.startTime = new Date().toISOString();
        }

        // Set end time when execution completes or fails
        if ((status === 'completed' || status === 'failed') && !context.execution.endTime) {
            context.execution.endTime = new Date().toISOString();
            
            // Calculate total time
            if (context.execution.startTime) {
                const startTime = new Date(context.execution.startTime).getTime();
                const endTime = new Date(context.execution.endTime).getTime();
                context.performance.totalTime = endTime - startTime;
            }
        }

        context.execution.status = status;
        if (output !== null) context.execution.output = output;
        if (exitCode !== null) context.execution.exitCode = exitCode;
        
        context.metadata.updatedAt = new Date().toISOString();
        console.log(` Execution updated: ${status} for ${context.pipelineId}`);
        
        return context;
    }

    /**
     * Set error in context
     * @param {Object} context - Pipeline context
     * @param {Error|string} error - Error object or message
     * @returns {Object} Updated context
     */
    setError(context, error) {
        if (!context || !context.pipelineId) {
            throw new Error('Invalid context provided');
        }

        const errorInfo = {
            message: error.message || error,
            stack: error.stack || null,
            timestamp: new Date().toISOString(),
            step: context.steps.length > 0 ? context.steps[context.steps.length - 1].stepName : 'unknown'
        };

        context.error = errorInfo;
        context.execution.status = 'failed';
        context.metadata.updatedAt = new Date().toISOString();
        
        console.error(` Error set for ${context.pipelineId}:`, errorInfo.message);
        return context;
    }

    /**
     * Get context by pipeline ID
     * @param {string} pipelineId - Pipeline ID
     * @returns {Object|null} Context object or null if not found
     */
    get(pipelineId) {
        return this.contexts.get(pipelineId) || null;
    }

    /**
     * Remove context (cleanup)
     * @param {string} pipelineId - Pipeline ID
     * @returns {boolean} True if removed
     */
    remove(pipelineId) {
        const removed = this.contexts.delete(pipelineId);
        if (removed) {
            console.log(` Context removed: ${pipelineId}`);
        }
        return removed;
    }

    /**
     * Clear context by execution ID (alias for remove)
     * @param {string} executionId - Execution ID  
     * @returns {boolean} True if removed
     */
    clearContext(executionId) {
        return this.remove(executionId);
    }

    /**
     * Create context object (for BaseStrategy compatibility)
     * @param {Object} data - Context data
     * @returns {Object} Context object
     */
    createContext(data) {
        return data; // Return as-is since BaseStrategy creates its own context
    }

    /**
     * Generate unique pipeline ID
     * @private
     * @returns {string} Pipeline ID
     */
    generatePipelineId() {
        const timestamp = Date.now();
        const random = crypto.randomBytes(4).toString('hex');
        return `pipe_${timestamp}_${random}`;
    }

    /**
     * Parse parameters from initial data
     * @private
     * @param {Object} data - Initial data
     * @returns {Object} Parsed parameters
     */
    parseParameters(data) {
        if (!data || typeof data !== 'object') {
            return {};
        }

        // Extract common parameters
        return {
            timeout: data.timeout || 30000,
            retry: data.retry || false,
            maxRetries: data.maxRetries || 3,
            silent: data.silent || false,
            workingDir: data.workingDir || process.cwd()
        };
    }

    /**
     * Get all active contexts (for monitoring)
     * @returns {Array} Array of context objects
     */
    getAll() {
        return Array.from(this.contexts.values());
    }

    /**
     * Clean up old contexts (older than specified minutes)
     * @param {number} maxAgeMinutes - Maximum age in minutes
     * @returns {number} Number of cleaned contexts
     */
    cleanup(maxAgeMinutes = 60) {
        const cutoffTime = Date.now() - (maxAgeMinutes * 60 * 1000);
        let cleaned = 0;

        for (const [pipelineId, context] of this.contexts.entries()) {
            const contextTime = new Date(context.metadata.createdAt).getTime();
            if (contextTime < cutoffTime) {
                this.contexts.delete(pipelineId);
                cleaned++;
            }
        }

        if (cleaned > 0) {
            console.log(` Cleaned up ${cleaned} old contexts`);
        }

        return cleaned;
    }

    /**
     * Get context manager status
     * @returns {Object} Status information
     */
    getStatus() {
        return {
            activeContexts: this.contexts.size,
            memoryUsage: process.memoryUsage(),
            ready: true
        };
    }
}

// Export class (not singleton)
module.exports = ContextManager;