/**
 * Approval Requests Composable
 * Fetch and manage approval requests
 */

import { ref, computed } from 'vue'
import type { ApprovalRequest, ApprovalFilter } from '../types'

export function useApprovalRequests() {
  const requests = ref<ApprovalRequest[]>([])
  const selectedRequestId = ref<string | null>(null)
  const isLoading = ref(false)
  const error = ref<string | null>(null)
  const filter = ref<ApprovalFilter>({})

  const mockRequests: ApprovalRequest[] = [
    {
      requestId: 'APR-2026-001',
      modelId: '00000000-0000-0000-0000-000000000001',
      modelName: 'Hawkeye-Alpha v2.1',
      action: 'activate',
      metadata: {
        pbo: 15.2,
        dsr: 96.5,
        oos: 1.8,
      },
      status: 'pending',
      requesterName: 'kjh2064',
      requestedAt: '2026-08-14T10:30:00Z',
    },
    {
      requestId: 'APR-2026-002',
      modelId: '00000000-0000-0000-0000-000000000002',
      modelName: 'Falcon-Beta v1.8',
      action: 'transition-phase',
      metadata: {
        currentPhase: 'Review',
        targetPhase: 'Manual Activation',
        pbo: 18.3,
        dsr: 94.2,
        oos: 2.1,
      },
      status: 'approved',
      requesterName: 'kjh2064',
      requestedAt: '2026-08-12T14:22:00Z',
      reviewerName: 'admin',
      reviewedAt: '2026-08-13T09:15:00Z',
      reviewComment: 'Metrics acceptable for transition. Approved.',
    },
    {
      requestId: 'APR-2026-003',
      modelId: '00000000-0000-0000-0000-000000000003',
      modelName: 'Eagle-Gamma v3.0',
      action: 'transition-phase',
      metadata: {
        currentPhase: 'Validate',
        targetPhase: 'Review',
        pbo: 20.5,
        dsr: 92.1,
        oos: 2.8,
      },
      status: 'rejected',
      requesterName: 'kjh2064',
      requestedAt: '2026-08-10T11:45:00Z',
      reviewerName: 'admin',
      reviewedAt: '2026-08-11T16:20:00Z',
      reviewComment: 'PBO exceeds 20% threshold. Needs further optimization.',
    },
  ]

  const selectedRequest = computed(() => {
    return requests.value.find(r => r.requestId === selectedRequestId.value) || null
  })

  const filteredRequests = computed(() => {
    let result = requests.value

    if (filter.value.status) {
      result = result.filter(r => r.status === filter.value.status)
    }

    if (filter.value.action) {
      result = result.filter(r => r.action === filter.value.action)
    }

    return result.sort(
      (a, b) => new Date(b.requestedAt).getTime() - new Date(a.requestedAt).getTime()
    )
  })

  const statusStats = computed(() => ({
    pending: requests.value.filter(r => r.status === 'pending').length,
    approved: requests.value.filter(r => r.status === 'approved').length,
    rejected: requests.value.filter(r => r.status === 'rejected').length,
    total: requests.value.length,
  }))

  async function fetchRequests() {
    isLoading.value = true
    error.value = null

    try {
      await new Promise(resolve => setTimeout(resolve, 600))
      requests.value = mockRequests
    } catch (err) {
      error.value = err instanceof Error ? err.message : 'Failed to fetch requests'
    } finally {
      isLoading.value = false
    }
  }

  function selectRequest(requestId: string) {
    selectedRequestId.value = requestId
  }

  function clearSelection() {
    selectedRequestId.value = null
  }

  function setFilter(newFilter: ApprovalFilter) {
    filter.value = newFilter
  }

  async function approveRequest(requestId: string, comment: string) {
    const req = requests.value.find(r => r.requestId === requestId)
    if (req) {
      req.status = 'approved'
      req.reviewerName = 'current-user'
      req.reviewedAt = new Date().toISOString()
      req.reviewComment = comment
    }
  }

  async function rejectRequest(requestId: string, comment: string) {
    const req = requests.value.find(r => r.requestId === requestId)
    if (req) {
      req.status = 'rejected'
      req.reviewerName = 'current-user'
      req.reviewedAt = new Date().toISOString()
      req.reviewComment = comment
    }
  }

  return {
    requests,
    filteredRequests,
    selectedRequest,
    selectedRequestId,
    isLoading,
    error,
    statusStats,
    fetchRequests,
    selectRequest,
    clearSelection,
    setFilter,
    approveRequest,
    rejectRequest,
  }
}