/**
 * CodeContextAnalyzer - Deep code analysis to understand project context
 * Reads actual code content line-by-line to extract meaningful context
 */
class CodeContextAnalyzer {
    constructor() {
        this.version = '1.0.0';
    }

    /**
     * Analyze code context deeply
     * @param {Array} files - All files with content
     * @returns {Object} Deep analysis
     */
    analyze(files) {
        const todoComments = this.extractTodoComments(files);
        const bugMarkers = this.extractBugMarkers(files);
        const checkboxes = this.extractCheckboxes(files);
        const migrationPatterns = this.detectMigrationPatterns(files);
        const updateNotes = this.extractUpdateNotes(files);
        const codeIssues = this.detectCodeIssues(files);

        return {
            todoComments,
            bugMarkers,
            checkboxes,
            migrationPatterns,
            updateNotes,
            codeIssues,
            summary: this.generateContextSummary({
                todoComments,
                bugMarkers,
                checkboxes,
                migrationPatterns,
                updateNotes,
                codeIssues
            })
        };
    }

    /**
     * Extract TODO comments from code
     */
    extractTodoComments(files) {
        const todos = [];
        const patterns = {
            todo: /\/\/\s*TODO:?\s*(.+)|\/\*\s*TODO:?\s*(.+?)\*\//gi,
            fixme: /\/\/\s*FIXME:?\s*(.+)|\/\*\s*FIXME:?\s*(.+?)\*\//gi,
            hack: /\/\/\s*HACK:?\s*(.+)|\/\*\s*HACK:?\s*(.+?)\*\//gi,
            note: /\/\/\s*NOTE:?\s*(.+)|\/\*\s*NOTE:?\s*(.+?)\*\//gi
        };

        files.forEach(file => {
            if (!file.content) return;

            const lines = file.content.split('\n');
            lines.forEach((line, index) => {
                for (const [type, pattern] of Object.entries(patterns)) {
                    const match = pattern.exec(line);
                    if (match) {
                        todos.push({
                            type: type.toUpperCase(),
                            message: (match[1] || match[2] || '').trim(),
                            filePath: file.filePath,
                            line: index + 1,
                            priority: this.determineTodoPriority(type, match[1] || match[2])
                        });
                    }
                    pattern.lastIndex = 0; // Reset regex
                }
            });
        });

        return todos;
    }

    /**
     * Determine TODO priority from content
     */
    determineTodoPriority(type, message) {
        if (type === 'FIXME') return 'HIGH';
        if (type === 'HACK') return 'HIGH';
        
        const text = message.toLowerCase();
        if (text.includes('critical') || text.includes('urgent') || text.includes('asap')) return 'CRITICAL';
        if (text.includes('important') || text.includes('must')) return 'HIGH';
        if (text.includes('should') || text.includes('consider')) return 'MEDIUM';
        
        return 'MEDIUM';
    }

    /**
     * Extract bug markers from code
     */
    extractBugMarkers(files) {
        const bugs = [];
        const patterns = {
            bug: /\/\/\s*BUG[-:]?\s*(.+)|\/\*\s*BUG[-:]?\s*(.+?)\*\//gi,
            issue: /\/\/\s*ISSUE[-:]?\s*(.+)|\/\*\s*ISSUE[-:]?\s*(.+?)\*\//gi,
            broken: /\/\/\s*BROKEN:?\s*(.+)|\/\*\s*BROKEN:?\s*(.+?)\*\//gi,
            error: /\/\/\s*ERROR:?\s*(.+)|\/\*\s*ERROR:?\s*(.+?)\*\//gi
        };

        files.forEach(file => {
            if (!file.content) return;

            const lines = file.content.split('\n');
            lines.forEach((line, index) => {
                for (const [type, pattern] of Object.entries(patterns)) {
                    const match = pattern.exec(line);
                    if (match) {
                        bugs.push({
                            type: type.toUpperCase(),
                            message: (match[1] || match[2] || '').trim(),
                            filePath: file.filePath,
                            line: index + 1,
                            severity: this.determineBugSeverity(match[1] || match[2])
                        });
                    }
                    pattern.lastIndex = 0;
                }
            });
        });

        return bugs;
    }

    /**
     * Determine bug severity from message
     */
    determineBugSeverity(message) {
        const text = message.toLowerCase();
        if (text.includes('critical') || text.includes('crash') || text.includes('data loss')) return 'CRITICAL';
        if (text.includes('security') || text.includes('vulnerability')) return 'CRITICAL';
        if (text.includes('major') || text.includes('important')) return 'HIGH';
        if (text.includes('minor') || text.includes('cosmetic')) return 'LOW';
        return 'MEDIUM';
    }

    /**
     * Extract checkboxes from markdown files
     */
    extractCheckboxes(files) {
        const checkboxes = {
            completed: [],
            pending: [],
            total: 0,
            completionRate: 0
        };

        const completedPattern = /^\s*-\s*\[x\]\s*(.+)/gi;
        const pendingPattern = /^\s*-\s*\[\s\]\s*(.+)/gi;

        files.filter(f => f.filePath.endsWith('.md')).forEach(file => {
            if (!file.content) return;

            const lines = file.content.split('\n');
            lines.forEach((line, index) => {
                let match;
                
                // Check for completed
                completedPattern.lastIndex = 0;
                if ((match = completedPattern.exec(line))) {
                    checkboxes.completed.push({
                        text: match[1].trim(),
                        filePath: file.filePath,
                        line: index + 1
                    });
                }

                // Check for pending
                pendingPattern.lastIndex = 0;
                if ((match = pendingPattern.exec(line))) {
                    checkboxes.pending.push({
                        text: match[1].trim(),
                        filePath: file.filePath,
                        line: index + 1
                    });
                }
            });
        });

        checkboxes.total = checkboxes.completed.length + checkboxes.pending.length;
        checkboxes.completionRate = checkboxes.total > 0 
            ? Math.round((checkboxes.completed.length / checkboxes.total) * 100) 
            : 0;

        return checkboxes;
    }

    /**
     * Detect migration patterns in code
     */
    detectMigrationPatterns(files) {
        const migrations = [];
        const patterns = {
            migrationComment: /\/\/\s*MIGRATION:?\s*(.+)|\/\*\s*MIGRATION:?\s*(.+?)\*\//gi,
            legacyCode: /\/\/\s*LEGACY:?\s*(.+)|\/\*\s*LEGACY:?\s*(.+?)\*\//gi,
            deprecated: /\/\/\s*DEPRECATED:?\s*(.+)|\/\*\s*DEPRECATED:?\s*(.+?)\*\//gi,
            newCode: /\/\/\s*NEW:?\s*(.+)|\/\*\s*NEW:?\s*(.+?)\*\//gi
        };

        files.forEach(file => {
            if (!file.content) return;

            const lines = file.content.split('\n');
            lines.forEach((line, index) => {
                for (const [type, pattern] of Object.entries(patterns)) {
                    const match = pattern.exec(line);
                    if (match) {
                        migrations.push({
                            type: type.toUpperCase(),
                            message: (match[1] || match[2] || '').trim(),
                            filePath: file.filePath,
                            line: index + 1,
                            status: this.determineMigrationStatus(type)
                        });
                    }
                    pattern.lastIndex = 0;
                }
            });
        });

        return migrations;
    }

    /**
     * Determine migration status
     */
    determineMigrationStatus(type) {
        if (type === 'LEGACY' || type === 'DEPRECATED') return 'NEEDS_MIGRATION';
        if (type === 'NEW') return 'MIGRATED';
        return 'IN_PROGRESS';
    }

    /**
     * Extract update notes from markdown
     */
    extractUpdateNotes(files) {
        const updates = [];
        const updatePattern = />\s*\*\*Update\s+(\d{1,2}\s+\w+\s+\d{4})[:\*\s]+(.+?)(?=\n\n|$)/gis;

        files.filter(f => f.filePath.endsWith('.md')).forEach(file => {
            if (!file.content) return;

            let match;
            while ((match = updatePattern.exec(file.content)) !== null) {
                updates.push({
                    date: match[1].trim(),
                    content: match[2].trim().substring(0, 200), // First 200 chars
                    filePath: file.filePath
                });
            }
        });

        return updates.sort((a, b) => {
            const dateA = new Date(a.date);
            const dateB = new Date(b.date);
            return dateB - dateA; // Newest first
        });
    }

    /**
     * Detect code issues from patterns
     */
    detectCodeIssues(files) {
        const issues = [];
        const issuePatterns = {
            emptyFunction: /function\s+\w+\s*\([^)]*\)\s*\{\s*\}/g,
            emptyClass: /class\s+\w+\s*\{\s*\}/g,
            console: /console\.(log|warn|error|debug)/g,
            debugger: /debugger;?/g,
            throwNotImplemented: /throw\s+new\s+Error\s*\(\s*['"`]not\s+implemented/gi
        };

        files.filter(f => f.filePath.match(/\.(js|ts|jsx|tsx)$/)).forEach(file => {
            if (!file.content) return;

            const lines = file.content.split('\n');
            
            for (const [issueType, pattern] of Object.entries(issuePatterns)) {
                let match;
                pattern.lastIndex = 0;
                
                while ((match = pattern.exec(file.content)) !== null) {
                    const lineNumber = file.content.substring(0, match.index).split('\n').length;
                    
                    issues.push({
                        type: issueType,
                        code: match[0],
                        filePath: file.filePath,
                        line: lineNumber,
                        severity: this.determineIssueSeverity(issueType)
                    });
                }
            }
        });

        return issues;
    }

    /**
     * Determine issue severity
     */
    determineIssueSeverity(issueType) {
        if (issueType === 'throwNotImplemented') return 'HIGH';
        if (issueType === 'emptyFunction' || issueType === 'emptyClass') return 'MEDIUM';
        if (issueType === 'debugger') return 'HIGH';
        if (issueType === 'console') return 'LOW';
        return 'MEDIUM';
    }

    /**
     * Generate context summary
     */
    generateContextSummary(context) {
        return {
            totalTodos: context.todoComments.length,
            criticalTodos: context.todoComments.filter(t => t.priority === 'CRITICAL').length,
            totalBugs: context.bugMarkers.length,
            criticalBugs: context.bugMarkers.filter(b => b.severity === 'CRITICAL').length,
            checkboxCompletion: context.checkboxes.completionRate,
            totalCheckboxes: context.checkboxes.total,
            completedCheckboxes: context.checkboxes.completed.length,
            migrationItems: context.migrationPatterns.length,
            needsMigration: context.migrationPatterns.filter(m => m.status === 'NEEDS_MIGRATION').length,
            updateNotes: context.updateNotes.length,
            latestUpdate: context.updateNotes[0]?.date || 'Unknown',
            codeIssues: context.codeIssues.length,
            criticalIssues: context.codeIssues.filter(i => i.severity === 'HIGH' || i.severity === 'CRITICAL').length
        };
    }
}

module.exports = CodeContextAnalyzer;