'use client'

import Link from 'next/link'
import { useState, useEffect } from 'react'
import { usePathname } from 'next/navigation'
import { useSDK, SDK_STEPS, SDK_PACKAGES, getStepsForPackage, type SDKStep, type SDKPackageId } from '@/lib/sdk'
import { CheckIcon, LockIcon, ArrowIcon } from './SDKPipelineSidebarIcons'

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

interface StepItemProps {
  step: SDKStep
  isActive: boolean
  isCompleted: boolean
  onNavigate: () => void
}

export function StepItem({ step, isActive, isCompleted, onNavigate }: StepItemProps) {
  return (
    <Link
      href={step.url}
      onClick={onNavigate}
      className={`flex items-center gap-3 px-3 py-2 rounded-lg transition-all ${
        isActive
          ? 'bg-purple-100 dark:bg-purple-900/30 text-purple-700 dark:text-purple-300 font-medium'
          : isCompleted
          ? 'text-green-600 dark:text-green-400 hover:bg-slate-100 dark:hover:bg-gray-800'
          : 'text-slate-600 dark:text-slate-400 hover:bg-slate-100 dark:hover:bg-gray-800'
      }`}
    >
      <span className="flex-1 text-sm truncate">{step.nameShort}</span>
      {isCompleted && !isActive && (
        <span className="flex-shrink-0 w-4 h-4 bg-green-500 text-white rounded-full flex items-center justify-center">
          <CheckIcon />
        </span>
      )}
      {isActive && (
        <span className="flex-shrink-0 w-2 h-2 bg-purple-500 rounded-full animate-pulse" />
      )}
    </Link>
  )
}

// =============================================================================
// PACKAGE SECTION
// =============================================================================

interface PackageSectionProps {
  pkg: (typeof SDK_PACKAGES)[number]
  steps: SDKStep[]
  completion: number
  currentStepId: string
  completedSteps: string[]
  isLocked: boolean
  onNavigate: () => void
  isExpanded: boolean
  onToggle: () => void
}

export function PackageSection({
  pkg,
  steps,
  completion,
  currentStepId,
  completedSteps,
  isLocked,
  onNavigate,
  isExpanded,
  onToggle,
}: PackageSectionProps) {
  return (
    <div className="space-y-2">
      {/* Package Header */}
      <button
        onClick={onToggle}
        disabled={isLocked}
        className={`w-full flex items-center justify-between px-3 py-2 rounded-lg transition-colors ${
          isLocked
            ? 'bg-slate-100 dark:bg-gray-800 opacity-50 cursor-not-allowed'
            : 'bg-slate-50 dark:bg-gray-800 hover:bg-slate-100 dark:hover:bg-gray-700'
        }`}
      >
        <div className="flex items-center gap-2">
          <div
            className={`w-7 h-7 rounded-full flex items-center justify-center text-sm ${
              isLocked
                ? 'bg-gray-200 text-gray-400'
                : completion === 100
                ? 'bg-green-500 text-white'
                : 'bg-purple-600 text-white'
            }`}
          >
            {isLocked ? <LockIcon /> : completion === 100 ? <CheckIcon /> : pkg.icon}
          </div>
          <div className="text-left">
            <div className={`text-sm font-medium ${isLocked ? 'text-slate-400' : 'text-slate-700 dark:text-slate-200'}`}>
              {pkg.order}. {pkg.nameShort}
            </div>
            <div className="text-xs text-slate-500 dark:text-slate-400">{completion}%</div>
          </div>
        </div>
        {!isLocked && (
          <svg
            className={`w-4 h-4 text-slate-400 transition-transform ${isExpanded ? 'rotate-180' : ''}`}
            fill="none"
            stroke="currentColor"
            viewBox="0 0 24 24"
          >
            <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 9l-7 7-7-7" />
          </svg>
        )}
      </button>

      {/* Progress Bar */}
      {!isLocked && (
        <div className="px-3">
          <div className="h-1.5 bg-slate-200 dark:bg-gray-700 rounded-full overflow-hidden">
            <div
              className={`h-full rounded-full transition-all duration-500 ${
                completion === 100 ? 'bg-green-500' : 'bg-purple-600'
              }`}
              style={{ width: `${completion}%` }}
            />
          </div>
        </div>
      )}

      {/* Steps List */}
      {isExpanded && !isLocked && (
        <div className="space-y-1 pl-2">
          {steps.map(step => (
            <StepItem
              key={step.id}
              step={step}
              isActive={currentStepId === step.id}
              isCompleted={completedSteps.includes(step.id)}
              onNavigate={onNavigate}
            />
          ))}
        </div>
      )}
    </div>
  )
}

// =============================================================================
// PIPELINE FLOW VISUALIZATION
// =============================================================================

export function PipelineFlow() {
  return (
    <div className="pt-3 border-t border-slate-200 dark:border-gray-700">
      <div className="text-xs font-medium text-slate-500 dark:text-slate-400 mb-2 px-1">
        Datenfluss
      </div>
      <div className="p-3 bg-slate-50 dark:bg-gray-900 rounded-lg">
        <div className="flex flex-col gap-1.5">
          {SDK_PACKAGES.map((pkg, idx) => (
            <div key={pkg.id} className="flex items-center gap-2 text-xs">
              <span className="w-5 h-5 rounded-full bg-purple-100 dark:bg-purple-900/30 flex items-center justify-center">
                {pkg.icon}
              </span>
              <span className="text-slate-600 dark:text-slate-400 flex-1">{pkg.nameShort}</span>
              {idx < SDK_PACKAGES.length - 1 && <ArrowIcon />}
            </div>
          ))}
        </div>
      </div>
    </div>
  )
}

// =============================================================================
// SIDEBAR CONTENT
// =============================================================================

interface SidebarContentProps {
  onNavigate: () => void
}

export function SidebarContent({ onNavigate }: SidebarContentProps) {
  const pathname = usePathname()
  const { state, packageCompletion } = useSDK()
  const [expandedPackages, setExpandedPackages] = useState<Record<SDKPackageId, boolean>>({
    'vorbereitung': true,
    'analyse': false,
    'dokumentation': false,
    'rechtliche-texte': false,
    'betrieb': false,
  })

  // Find current step
  const currentStep = SDK_STEPS.find(s => s.url === pathname)
  const currentStepId = currentStep?.id || ''

  // Auto-expand current package
  useEffect(() => {
    if (currentStep) {
      setExpandedPackages(prev => ({
        ...prev,
        [currentStep.package]: true,
      }))
    }
  }, [currentStep])

  const togglePackage = (packageId: SDKPackageId) => {
    setExpandedPackages(prev => ({ ...prev, [packageId]: !prev[packageId] }))
  }

  const isPackageLocked = (packageId: SDKPackageId): boolean => {
    if (state.preferences?.allowParallelWork) return false
    const pkg = SDK_PACKAGES.find(p => p.id === packageId)
    if (!pkg || pkg.order === 1) return false

    const prevPkg = SDK_PACKAGES.find(p => p.order === pkg.order - 1)
    if (!prevPkg) return false

    return packageCompletion[prevPkg.id] < 100
  }

  // Filter steps based on visibleWhen conditions
  const getVisibleStepsForPackage = (packageId: SDKPackageId): SDKStep[] => {
    const steps = getStepsForPackage(packageId)
    return steps.filter(step => {
      if (step.visibleWhen) return step.visibleWhen(state)
      return true
    })
  }

  return (
    <div className="space-y-4">
      {/* Packages */}
      {SDK_PACKAGES.map(pkg => (
        <PackageSection
          key={pkg.id}
          pkg={pkg}
          steps={getVisibleStepsForPackage(pkg.id)}
          completion={packageCompletion[pkg.id]}
          currentStepId={currentStepId}
          completedSteps={state.completedSteps}
          isLocked={isPackageLocked(pkg.id)}
          onNavigate={onNavigate}
          isExpanded={expandedPackages[pkg.id]}
          onToggle={() => togglePackage(pkg.id)}
        />
      ))}

      {/* Pipeline Flow */}
      <PipelineFlow />

      {/* Quick Info */}
      {currentStep && (
        <div className="pt-3 border-t border-slate-200 dark:border-gray-700">
          <div className="text-xs text-slate-600 dark:text-slate-400 p-3 bg-slate-50 dark:bg-gray-800 rounded-lg">
            <strong className="text-slate-700 dark:text-slate-300">Aktuell:</strong>{' '}
            {currentStep.description}
          </div>
        </div>
      )}
    </div>
  )
}