import {SymbolGraph, Symbol, DependencyEdge} from './symbol-graph'

export interface LayerDefinition {
  name: string
  patterns: string[]
  priority: number
}

export interface ArchitecturalRule {
  fromLayer: string
  toLayer: string
  allowed: boolean
  severity: 'critical' | 'major' | 'minor'
  description: string
}

export interface ArchitecturalViolation {
  from: string
  to: string
  fromLayer: string
  toLayer: string
  severity: 'critical' | 'major' | 'minor'
  description: string
  file?: string
  suggestedFix?: string
}

export interface ArchitectureAnalysis {
  violations: ArchitecturalViolation[]
  layerAssignments: Map<string, string>
  unassignedFiles: string[]
  statistics: {
    totalViolations: number
    criticalCount: number
    majorCount: number
    minorCount: number
  }
}

const DEFAULT_LAYERS: LayerDefinition[] = [
  {
    name: 'ui',
    patterns: [
      '**/components/**',
      '**/pages/**',
      '**/views/**',
      '**/screens/**',
      '**/ui/**',
      '**/frontend/**'
    ],
    priority: 1
  },
  {
    name: 'api',
    patterns: [
      '**/api/**',
      '**/controllers/**',
      '**/handlers/**',
      '**/routes/**',
      '**/endpoints/**'
    ],
    priority: 2
  },
  {
    name: 'services',
    patterns: [
      '**/services/**',
      '**/business/**',
      '**/domain/**',
      '**/usecases/**'
    ],
    priority: 3
  },
  {
    name: 'data',
    patterns: [
      '**/models/**',
      '**/schemas/**',
      '**/entities/**',
      '**/repositories/**',
      '**/dal/**'
    ],
    priority: 4
  },
  {
    name: 'infrastructure',
    patterns: [
      '**/db/**',
      '**/database/**',
      '**/cache/**',
      '**/queue/**',
      '**/storage/**',
      '**/external/**'
    ],
    priority: 5
  },
  {
    name: 'shared',
    patterns: [
      '**/shared/**',
      '**/common/**',
      '**/utils/**',
      '**/lib/**',
      '**/types/**'
    ],
    priority: 0
  }
]

const DEFAULT_RULES: ArchitecturalRule[] = [
  {
    fromLayer: 'ui',
    toLayer: 'data',
    allowed: false,
    severity: 'critical',
    description: 'UI should not directly access data layer'
  },
  {
    fromLayer: 'ui',
    toLayer: 'infrastructure',
    allowed: false,
    severity: 'critical',
    description: 'UI should not directly access infrastructure'
  },
  {
    fromLayer: 'api',
    toLayer: 'ui',
    allowed: false,
    severity: 'major',
    description: 'API layer should not depend on UI'
  },
  {
    fromLayer: 'api',
    toLayer: 'infrastructure',
    allowed: true,
    severity: 'minor',
    description: 'API may access infrastructure (database, cache)'
  },
  {
    fromLayer: 'services',
    toLayer: 'ui',
    allowed: false,
    severity: 'major',
    description: 'Services should not depend on UI'
  },
  {
    fromLayer: 'services',
    toLayer: 'infrastructure',
    allowed: true,
    severity: 'minor',
    description: 'Services may access infrastructure'
  },
  {
    fromLayer: 'data',
    toLayer: 'api',
    allowed: false,
    severity: 'major',
    description: 'Data layer should not depend on API layer'
  },
  {
    fromLayer: 'data',
    toLayer: 'infrastructure',
    allowed: false,
    severity: 'critical',
    description: 'Data layer should not depend on infrastructure'
  },
  {
    fromLayer: 'shared',
    toLayer: 'ui',
    allowed: false,
    severity: 'minor',
    description: 'Shared code should not depend on UI'
  },
  {
    fromLayer: 'shared',
    toLayer: 'api',
    allowed: false,
    severity: 'minor',
    description: 'Shared code should not depend on API'
  }
]

export class ArchitecturalAnalyzer {
  private layers: LayerDefinition[]
  private rules: ArchitecturalRule[]
  private layerCache: Map<string, string>

  constructor(
    layers: LayerDefinition[] = DEFAULT_LAYERS,
    rules: ArchitecturalRule[] = DEFAULT_RULES
  ) {
    this.layers = layers
    this.rules = rules
    this.layerCache = new Map()
  }

  analyze(symbolGraph: SymbolGraph): ArchitectureAnalysis {
    const violations: ArchitecturalViolation[] = []
    const layerAssignments = new Map<string, string>()
    const unassignedFiles: string[] = []

    for (const [key, symbol] of symbolGraph.symbols) {
      const file = symbol.file
      if (!layerAssignments.has(file)) {
        const layer = this.assignLayer(file)
        layerAssignments.set(file, layer)
        if (layer === 'unassigned') {
          unassignedFiles.push(file)
        }
      }
    }

    for (const edge of symbolGraph.edges) {
      const fromLayer = layerAssignments.get(edge.from) || 'unassigned'
      const toLayer = this.resolveImportToLayer(edge.to, symbolGraph)

      if (fromLayer === 'unassigned' || toLayer === 'unassigned') continue

      const rule = this.findRule(fromLayer, toLayer)
      if (rule && !rule.allowed) {
        violations.push({
          from: edge.from,
          to: edge.to,
          fromLayer,
          toLayer,
          severity: rule.severity,
          description: rule.description,
          file: edge.from
        })
      }
    }

    const statistics = {
      totalViolations: violations.length,
      criticalCount: violations.filter(v => v.severity === 'critical').length,
      majorCount: violations.filter(v => v.severity === 'major').length,
      minorCount: violations.filter(v => v.severity === 'minor').length
    }

    return {
      violations,
      layerAssignments,
      unassignedFiles,
      statistics
    }
  }

  private assignLayer(filePath: string): string {
    const cached = this.layerCache.get(filePath)
    if (cached) return cached

    const normalizedPath = filePath.replace(/\\/g, '/').toLowerCase()

    for (const layer of this.layers) {
      for (const pattern of layer.patterns) {
        if (this.matchPattern(normalizedPath, pattern.toLowerCase())) {
          this.layerCache.set(filePath, layer.name)
          return layer.name
        }
      }
    }

    this.layerCache.set(filePath, 'unassigned')
    return 'unassigned'
  }

  private matchPattern(path: string, pattern: string): boolean {
    const regexPattern = pattern
      .replace(/\*\*/g, '<<DOUBLE_STAR>>')
      .replace(/\*/g, '[^/]*')
      .replace(/<<DOUBLE_STAR>>/g, '.*')
      .replace(/\?/g, '.')

    try {
      const regex = new RegExp(`^${regexPattern}$`)
      return regex.test(path) || this.matchGlob(path, pattern)
    } catch {
      return this.matchGlob(path, pattern)
    }
  }

  private matchGlob(path: string, pattern: string): boolean {
    const parts = path.split('/')
    const patternParts = pattern.split('/')

    let pi = 0
    let psi = 0

    while (pi < parts.length && psi < patternParts.length) {
      const patternPart = patternParts[psi]

      if (patternPart === '**') {
        if (psi === patternParts.length - 1) {
          return true
        }
        const nextPattern = patternParts[psi + 1]
        while (pi < parts.length) {
          if (this.matchSingle(parts[pi], nextPattern)) {
            if (
              this.matchGlob(
                parts.slice(pi).join('/'),
                patternParts.slice(psi + 1).join('/')
              )
            ) {
              return true
            }
          }
          pi++
        }
        return false
      }

      if (!this.matchSingle(parts[pi], patternPart)) {
        return false
      }

      pi++
      psi++
    }

    return pi === parts.length && psi === patternParts.length
  }

  private matchSingle(part: string, pattern: string): boolean {
    if (pattern === '*') return part.length > 0
    if (pattern === '**') return true

    const regexPattern = pattern
      .replace(/\./g, '\\.')
      .replace(/\*/g, '[^/]*')
      .replace(/\?/g, '.')

    try {
      const regex = new RegExp(`^${regexPattern}$`)
      return regex.test(part)
    } catch {
      return part === pattern
    }
  }

  private resolveImportToLayer(
    importPath: string,
    symbolGraph: SymbolGraph
  ): string {
    const normalizedImport = importPath.replace(/['"]/g, '').replace(/\\/g, '/')

    for (const [key, symbol] of symbolGraph.symbols) {
      const symbolPath = symbol.file
      if (
        symbolPath.includes(normalizedImport) ||
        normalizedImport.includes(symbolPath)
      ) {
        return this.assignLayer(symbolPath)
      }
    }

    if (normalizedImport.startsWith('.')) {
      return 'unassigned'
    }

    if (normalizedImport.includes('/node_modules/')) {
      return 'external'
    }

    if (
      normalizedImport.includes('/shared/') ||
      normalizedImport.includes('/common/')
    ) {
      return 'shared'
    }

    return 'unassigned'
  }

  private findRule(
    fromLayer: string,
    toLayer: string
  ): ArchitecturalRule | undefined {
    return this.rules.find(
      r => r.fromLayer === fromLayer && r.toLayer === toLayer
    )
  }

  getDependencyGraph(
    layerAssignments: Map<string, string>
  ): Map<string, Set<string>> {
    const graph = new Map<string, Set<string>>()

    for (const [file, layer] of layerAssignments) {
      if (!graph.has(layer)) {
        graph.set(layer, new Set())
      }
    }

    return graph
  }

  generateReport(analysis: ArchitectureAnalysis): string {
    const lines: string[] = []

    lines.push('# Architectural Violation Report')
    lines.push('')
    lines.push(`Total Violations: ${analysis.statistics.totalViolations}`)
    lines.push(`  - Critical: ${analysis.statistics.criticalCount}`)
    lines.push(`  - Major: ${analysis.statistics.majorCount}`)
    lines.push(`  - Minor: ${analysis.statistics.minorCount}`)
    lines.push('')

    if (analysis.violations.length > 0) {
      lines.push('## Violations')
      lines.push('')

      const groupedBySeverity = {
        critical: analysis.violations.filter(v => v.severity === 'critical'),
        major: analysis.violations.filter(v => v.severity === 'major'),
        minor: analysis.violations.filter(v => v.severity === 'minor')
      }

      for (const severity of ['critical', 'major', 'minor'] as const) {
        const violations = groupedBySeverity[severity]
        if (violations.length === 0) continue

        lines.push(`### ${severity.toUpperCase()} (${violations.length})`)
        lines.push('')

        for (const v of violations) {
          lines.push(
            `- **${v.fromLayer}** → **${v.toLayer}**: ${v.description}`
          )
          lines.push(`  - File: \`${v.file || v.from}\``)
          lines.push(`  - Import: \`${v.to}\``)
        }
        lines.push('')
      }
    }

    return lines.join('\n')
  }
}

export function analyzeArchitecture(
  symbolGraph: SymbolGraph
): ArchitectureAnalysis {
  const analyzer = new ArchitecturalAnalyzer()
  return analyzer.analyze(symbolGraph)
}