'use client'

import React from 'react'
import Link from 'next/link'
import { usePathname } from 'next/navigation'
import { useSDK, SDK_STEPS, getStepsForPhase, SDKPhase } from '@/lib/sdk'

// =============================================================================
// ICONS
// =============================================================================

const CheckIcon = () => (
  <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M5 13l4 4L19 7" />
  </svg>
)

const LockIcon = () => (
  <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 15v2m-6 4h12a2 2 0 002-2v-6a2 2 0 00-2-2H6a2 2 0 00-2 2v6a2 2 0 002 2zm10-10V7a4 4 0 00-8 0v4h8z" />
  </svg>
)

const WarningIcon = () => (
  <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z" />
  </svg>
)

const ChevronDownIcon = ({ className = '' }: { className?: string }) => (
  <svg className={`w-4 h-4 ${className}`} fill="none" stroke="currentColor" viewBox="0 0 24 24">
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
  </svg>
)

const CollapseIcon = ({ collapsed }: { collapsed: boolean }) => (
  <svg
    className={`w-5 h-5 transition-transform duration-300 ${collapsed ? 'rotate-180' : ''}`}
    fill="none"
    stroke="currentColor"
    viewBox="0 0 24 24"
  >
    <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M11 19l-7-7 7-7m8 14l-7-7 7-7" />
  </svg>
)

// =============================================================================
// PHASE INDICATOR
// =============================================================================

interface PhaseIndicatorProps {
  phase: SDKPhase
  title: string
  completion: number
  isActive: boolean
  isExpanded: boolean
  onToggle: () => void
  collapsed: boolean
}

function PhaseIndicator({ phase, title, completion, isActive, isExpanded, onToggle, collapsed }: PhaseIndicatorProps) {
  if (collapsed) {
    return (
      <button
        onClick={onToggle}
        className={`w-full flex items-center justify-center py-3 transition-colors ${
          isActive
            ? 'bg-purple-50 border-l-4 border-purple-600'
            : 'hover:bg-gray-50 border-l-4 border-transparent'
        }`}
        title={`${title} (${completion}%)`}
      >
        <div
          className={`w-8 h-8 rounded-full flex items-center justify-center text-sm font-bold ${
            isActive
              ? 'bg-purple-600 text-white'
              : completion === 100
              ? 'bg-green-500 text-white'
              : 'bg-gray-200 text-gray-600'
          }`}
        >
          {completion === 100 ? <CheckIcon /> : phase}
        </div>
      </button>
    )
  }

  return (
    <button
      onClick={onToggle}
      className={`w-full flex items-center justify-between px-4 py-3 text-left transition-colors ${
        isActive
          ? 'bg-purple-50 border-l-4 border-purple-600'
          : 'hover:bg-gray-50 border-l-4 border-transparent'
      }`}
    >
      <div className="flex items-center gap-3">
        <div
          className={`w-8 h-8 rounded-full flex items-center justify-center text-sm font-bold ${
            isActive
              ? 'bg-purple-600 text-white'
              : completion === 100
              ? 'bg-green-500 text-white'
              : 'bg-gray-200 text-gray-600'
          }`}
        >
          {completion === 100 ? <CheckIcon /> : phase}
        </div>
        <div>
          <div className={`font-medium ${isActive ? 'text-purple-900' : 'text-gray-700'}`}>
            {title}
          </div>
          <div className="text-xs text-gray-500">{completion}% abgeschlossen</div>
        </div>
      </div>
      <ChevronDownIcon className={`transition-transform ${isExpanded ? 'rotate-180' : ''}`} />
    </button>
  )
}

// =============================================================================
// PROGRESS BAR
// =============================================================================

interface ProgressBarProps {
  value: number
  className?: string
}

function ProgressBar({ value, className = '' }: ProgressBarProps) {
  return (
    <div className={`h-1 bg-gray-200 rounded-full overflow-hidden ${className}`}>
      <div
        className="h-full bg-purple-600 rounded-full transition-all duration-500"
        style={{ width: `${Math.min(100, Math.max(0, value))}%` }}
      />
    </div>
  )
}

// =============================================================================
// STEP ITEM
// =============================================================================

interface StepItemProps {
  step: (typeof SDK_STEPS)[number]
  isActive: boolean
  isCompleted: boolean
  isLocked: boolean
  checkpointStatus?: 'passed' | 'failed' | 'warning' | 'pending'
  collapsed: boolean
}

function StepItem({ step, isActive, isCompleted, isLocked, checkpointStatus, collapsed }: StepItemProps) {
  const content = (
    <div
      className={`flex items-center gap-3 px-4 py-2.5 text-sm transition-colors ${
        collapsed ? 'justify-center' : ''
      } ${
        isActive
          ? 'bg-purple-100 text-purple-900 font-medium'
          : isLocked
          ? 'text-gray-400 cursor-not-allowed'
          : 'text-gray-600 hover:bg-gray-50 hover:text-gray-900'
      }`}
      title={collapsed ? step.name : undefined}
    >
      {/* Step indicator */}
      <div className="flex-shrink-0">
        {isCompleted ? (
          <div className="w-5 h-5 rounded-full bg-green-500 text-white flex items-center justify-center">
            <CheckIcon />
          </div>
        ) : isLocked ? (
          <div className="w-5 h-5 rounded-full bg-gray-200 text-gray-400 flex items-center justify-center">
            <LockIcon />
          </div>
        ) : isActive ? (
          <div className="w-5 h-5 rounded-full bg-purple-600 flex items-center justify-center">
            <div className="w-2 h-2 rounded-full bg-white" />
          </div>
        ) : (
          <div className="w-5 h-5 rounded-full border-2 border-gray-300" />
        )}
      </div>

      {/* Step name - hidden when collapsed */}
      {!collapsed && <span className="flex-1 truncate">{step.nameShort}</span>}

      {/* Checkpoint status - hidden when collapsed */}
      {!collapsed && checkpointStatus && checkpointStatus !== 'pending' && (
        <div className="flex-shrink-0">
          {checkpointStatus === 'passed' ? (
            <div className="w-4 h-4 rounded-full bg-green-100 text-green-600 flex items-center justify-center">
              <CheckIcon />
            </div>
          ) : checkpointStatus === 'failed' ? (
            <div className="w-4 h-4 rounded-full bg-red-100 text-red-600 flex items-center justify-center">
              <span className="text-xs font-bold">!</span>
            </div>
          ) : (
            <div className="w-4 h-4 rounded-full bg-yellow-100 text-yellow-600 flex items-center justify-center">
              <WarningIcon />
            </div>
          )}
        </div>
      )}
    </div>
  )

  if (isLocked) {
    return content
  }

  return (
    <Link href={step.url} className="block">
      {content}
    </Link>
  )
}

// =============================================================================
// ADDITIONAL MODULE ITEM
// =============================================================================

interface AdditionalModuleItemProps {
  href: string
  icon: React.ReactNode
  label: string
  isActive: boolean
  collapsed: boolean
}

function AdditionalModuleItem({ href, icon, label, isActive, collapsed }: AdditionalModuleItemProps) {
  return (
    <Link
      href={href}
      className={`flex items-center gap-3 px-4 py-2.5 text-sm transition-colors ${
        collapsed ? 'justify-center' : ''
      } ${
        isActive
          ? 'bg-purple-100 text-purple-900 font-medium'
          : 'text-gray-600 hover:bg-gray-50 hover:text-gray-900'
      }`}
      title={collapsed ? label : undefined}
    >
      {icon}
      {!collapsed && <span>{label}</span>}
    </Link>
  )
}

// =============================================================================
// MAIN SIDEBAR
// =============================================================================

interface SDKSidebarProps {
  collapsed?: boolean
  onCollapsedChange?: (collapsed: boolean) => void
}

export function SDKSidebar({ collapsed = false, onCollapsedChange }: SDKSidebarProps) {
  const pathname = usePathname()
  const { state, phase1Completion, phase2Completion, getCheckpointStatus } = useSDK()
  const [expandedPhases, setExpandedPhases] = React.useState<Record<number, boolean>>({
    1: true,
    2: true,
  })

  const togglePhase = (phase: number) => {
    setExpandedPhases(prev => ({ ...prev, [phase]: !prev[phase] }))
  }

  const phase1Steps = getStepsForPhase(1)
  const phase2Steps = getStepsForPhase(2)

  const isStepLocked = (step: (typeof SDK_STEPS)[number]): boolean => {
    if (state.preferences?.allowParallelWork) return false
    return step.prerequisiteSteps.some(prereq => !state.completedSteps.includes(prereq))
  }

  const getStepCheckpointStatus = (step: (typeof SDK_STEPS)[number]): 'passed' | 'failed' | 'warning' | 'pending' => {
    const status = getCheckpointStatus(step.checkpointId)
    if (!status) return 'pending'
    if (status.passed) return 'passed'
    if (status.errors.length > 0) return 'failed'
    if (status.warnings.length > 0) return 'warning'
    return 'pending'
  }

  return (
    <aside className={`fixed left-0 top-0 h-screen ${collapsed ? 'w-16' : 'w-64'} bg-white border-r border-gray-200 flex flex-col z-40 transition-all duration-300`}>
      {/* Header */}
      <div className={`p-4 border-b border-gray-200 ${collapsed ? 'flex justify-center' : ''}`}>
        <Link href="/sdk" className={`flex items-center gap-3 ${collapsed ? 'justify-center' : ''}`}>
          <div className="w-10 h-10 rounded-xl bg-gradient-to-br from-purple-600 to-indigo-600 flex items-center justify-center flex-shrink-0">
            <svg className="w-6 h-6 text-white" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M9 12l2 2 4-4m5.618-4.016A11.955 11.955 0 0112 2.944a11.955 11.955 0 01-8.618 3.04A12.02 12.02 0 003 9c0 5.591 3.824 10.29 9 11.622 5.176-1.332 9-6.03 9-11.622 0-1.042-.133-2.052-.382-3.016z"
              />
            </svg>
          </div>
          {!collapsed && (
            <div>
              <div className="font-bold text-gray-900">AI Compliance</div>
              <div className="text-xs text-gray-500">SDK</div>
            </div>
          )}
        </Link>
      </div>

      {/* Overall Progress - hidden when collapsed */}
      {!collapsed && (
        <div className="px-4 py-3 border-b border-gray-100">
          <div className="flex items-center justify-between text-sm mb-2">
            <span className="text-gray-600">Gesamtfortschritt</span>
            <span className="font-medium text-purple-600">
              {Math.round((phase1Completion + phase2Completion) / 2)}%
            </span>
          </div>
          <ProgressBar value={(phase1Completion + phase2Completion) / 2} />
        </div>
      )}

      {/* Navigation */}
      <nav className="flex-1 overflow-y-auto">
        {/* Phase 1 */}
        <div>
          <PhaseIndicator
            phase={1}
            title="Compliance Assessment"
            completion={phase1Completion}
            isActive={state.currentPhase === 1}
            isExpanded={expandedPhases[1]}
            onToggle={() => togglePhase(1)}
            collapsed={collapsed}
          />
          {expandedPhases[1] && (
            <div className="py-1">
              {phase1Steps.map(step => (
                <StepItem
                  key={step.id}
                  step={step}
                  isActive={pathname === step.url}
                  isCompleted={state.completedSteps.includes(step.id)}
                  isLocked={isStepLocked(step)}
                  checkpointStatus={getStepCheckpointStatus(step)}
                  collapsed={collapsed}
                />
              ))}
            </div>
          )}
        </div>

        {/* Phase 2 */}
        <div className="border-t border-gray-100">
          <PhaseIndicator
            phase={2}
            title="Dokumentengenerierung"
            completion={phase2Completion}
            isActive={state.currentPhase === 2}
            isExpanded={expandedPhases[2]}
            onToggle={() => togglePhase(2)}
            collapsed={collapsed}
          />
          {expandedPhases[2] && (
            <div className="py-1">
              {phase2Steps.map(step => (
                <StepItem
                  key={step.id}
                  step={step}
                  isActive={pathname === step.url}
                  isCompleted={state.completedSteps.includes(step.id)}
                  isLocked={isStepLocked(step)}
                  checkpointStatus={getStepCheckpointStatus(step)}
                  collapsed={collapsed}
                />
              ))}
            </div>
          )}
        </div>

        {/* Additional Modules */}
        <div className="border-t border-gray-100 py-2">
          {!collapsed && (
            <div className="px-4 py-2 text-xs font-medium text-gray-400 uppercase tracking-wider">
              Zusatzmodule
            </div>
          )}
          <AdditionalModuleItem
            href="/sdk/rag"
            icon={
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M21 21l-6-6m2-5a7 7 0 11-14 0 7 7 0 0114 0z"
                />
              </svg>
            }
            label="Legal RAG"
            isActive={pathname === '/sdk/rag'}
            collapsed={collapsed}
          />
          <AdditionalModuleItem
            href="/sdk/quality"
            icon={
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M9 12l2 2 4-4m6 2a9 9 0 11-18 0 9 9 0 0118 0z"
                />
              </svg>
            }
            label="AI Quality"
            isActive={pathname === '/sdk/quality'}
            collapsed={collapsed}
          />
          <AdditionalModuleItem
            href="/sdk/security-backlog"
            icon={
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z"
                />
              </svg>
            }
            label="Security Backlog"
            isActive={pathname === '/sdk/security-backlog'}
            collapsed={collapsed}
          />
        </div>
      </nav>

      {/* Footer */}
      <div className={`${collapsed ? 'p-2' : 'p-4'} border-t border-gray-200 bg-gray-50`}>
        {/* Collapse Toggle */}
        <button
          onClick={() => onCollapsedChange?.(!collapsed)}
          className={`w-full flex items-center justify-center gap-2 ${collapsed ? 'p-2' : 'px-4 py-2'} text-sm text-gray-600 hover:text-gray-900 hover:bg-gray-100 rounded-lg transition-colors ${collapsed ? '' : 'mb-2'}`}
          title={collapsed ? 'Sidebar erweitern' : 'Sidebar einklappen'}
        >
          <CollapseIcon collapsed={collapsed} />
          {!collapsed && <span>Einklappen</span>}
        </button>

        {/* Export Button */}
        {!collapsed && (
          <button
            onClick={() => {}}
            className="w-full flex items-center justify-center gap-2 px-4 py-2 text-sm text-purple-600 hover:text-purple-700 hover:bg-purple-50 rounded-lg transition-colors"
          >
            <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12"
              />
            </svg>
            <span>Exportieren</span>
          </button>
        )}
      </div>
    </aside>
  )
}
