/**
 * Composable: useModels
 * TanStack Query integration for model data fetching
 */

import { useQuery, useMutation, useQueryClient } from '@tanstack/vue-query'
import { ref } from 'vue'

export type ModelPhase =
  | 'Freeze'
  | 'Mature'
  | 'Score'
  | 'Diagnose'
  | 'Hypothesis'
  | 'Challenger'
  | 'Validate'
  | 'Review'
  | 'Manual Activation'

export interface Model {
  modelId: string
  name: string
  phase: ModelPhase
  active: boolean
  lastValidation: string
  pbo: number
  dsr: number
  returnMtd: number
  createdAt: string
}

export interface ModelDetail extends Model {
  description: string
  updatedAt: string
  oos: number
  validationHistory: ValidationEntry[]
  configuration: {
    lookbackPeriod: number
    rebalanceFrequency: string
    riskLimit: number
    maxPositions: number
    minLiquidityDays: number
  }
}

export interface ValidationEntry {
  date: string
  phase: ModelPhase
  pbo: number
  dsr: number
  oos: number
  status: 'approved' | 'rejected'
}

export interface ModelListParams {
  page?: number
  pageSize?: number
  search?: string
  phase?: string
  active?: boolean
}

export interface ModelListResponse {
  items: Model[]
  total: number
  page: number
  pageSize: number
}

// Mock API client (replace with actual API calls)
const apiClient = {
  async listModels(params: ModelListParams): Promise<ModelListResponse> {
    await new Promise(resolve => setTimeout(resolve, 300))

    const items: Model[] = [
      {
        modelId: '00000000-0000-0000-0000-000000000001',
        name: 'Alpha Strategy v1',
        phase: 'Validate',
        active: false,
        lastValidation: '2026-08-10',
        pbo: 15.2,
        dsr: 96.5,
        returnMtd: 12.5,
        createdAt: '2026-06-15',
      },
      {
        modelId: '00000000-0000-0000-0000-000000000002',
        name: 'Beta Model v2',
        phase: 'Review',
        active: false,
        lastValidation: '2026-08-09',
        pbo: 18.3,
        dsr: 94.2,
        returnMtd: 8.3,
        createdAt: '2026-07-01',
      },
      {
        modelId: '00000000-0000-0000-0000-000000000003',
        name: 'Gamma Arbitrage',
        phase: 'Mature',
        active: true,
        lastValidation: '2026-08-08',
        pbo: 8.5,
        dsr: 98.1,
        returnMtd: 18.7,
        createdAt: '2026-05-10',
      },
    ]

    return {
      items: items.slice(0, params.pageSize || 50),
      total: items.length,
      page: params.page || 1,
      pageSize: params.pageSize || 50,
    }
  },

  async getModelDetail(modelId: string): Promise<ModelDetail> {
    await new Promise(resolve => setTimeout(resolve, 200))

    return {
      modelId,
      name: 'Alpha Strategy v1',
      description: 'Quantitative trading strategy based on technical analysis',
      phase: 'Validate',
      active: false,
      lastValidation: '2026-08-10',
      pbo: 15.2,
      dsr: 96.5,
      oos: 1.8,
      returnMtd: 12.5,
      createdAt: '2026-06-15',
      updatedAt: '2026-08-10',
      validationHistory: [
        {
          date: '2026-08-10',
          phase: 'Validate',
          pbo: 15.2,
          dsr: 96.5,
          oos: 1.8,
          status: 'approved',
        },
        {
          date: '2026-08-05',
          phase: 'Review',
          pbo: 16.1,
          dsr: 95.2,
          oos: 2.1,
          status: 'approved',
        },
      ],
      configuration: {
        lookbackPeriod: 252,
        rebalanceFrequency: 'daily',
        riskLimit: 2.0,
        maxPositions: 20,
        minLiquidityDays: 10,
      },
    }
  },

  async activateModel(modelId: string) {
    await new Promise(resolve => setTimeout(resolve, 500))
    return { modelId, active: true }
  },

  async deactivateModel(modelId: string) {
    await new Promise(resolve => setTimeout(resolve, 500))
    return { modelId, active: false }
  },

  async transitionPhase(modelId: string, newPhase: ModelPhase) {
    await new Promise(resolve => setTimeout(resolve, 500))
    return { modelId, phase: newPhase }
  },
}

// Query key factories
export const modelQueryKeys = {
  all: ['models'] as const,
  lists: () => [...modelQueryKeys.all, 'list'] as const,
  list: (params: ModelListParams) => [...modelQueryKeys.lists(), params] as const,
  details: () => [...modelQueryKeys.all, 'detail'] as const,
  detail: (modelId: string) => [...modelQueryKeys.details(), modelId] as const,
}

/**
 * Fetch list of models with pagination
 */
export function useModelsList(params: ModelListParams = {}) {
  return useQuery({
    queryKey: modelQueryKeys.list(params),
    queryFn: () => apiClient.listModels(params),
    staleTime: 5 * 60 * 1000, // 5 minutes
    gcTime: 10 * 60 * 1000, // 10 minutes
  })
}

/**
 * Fetch single model detail
 */
export function useModelDetail(modelId: string) {
  return useQuery({
    queryKey: modelQueryKeys.detail(modelId),
    queryFn: () => apiClient.getModelDetail(modelId),
    enabled: !!modelId,
    staleTime: 5 * 60 * 1000,
    gcTime: 10 * 60 * 1000,
  })
}

/**
 * Activate a model (mutation)
 */
export function useActivateModel() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: (modelId: string) => apiClient.activateModel(modelId),
    onSuccess: (data) => {
      // Invalidate model detail and list
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.detail(data.modelId) })
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.lists() })
    },
  })
}

/**
 * Deactivate a model (mutation)
 */
export function useDeactivateModel() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: (modelId: string) => apiClient.deactivateModel(modelId),
    onSuccess: (data) => {
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.detail(data.modelId) })
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.lists() })
    },
  })
}

/**
 * Transition model to next phase (mutation)
 */
export function useTransitionPhase() {
  const queryClient = useQueryClient()

  return useMutation({
    mutationFn: ({ modelId, phase }: { modelId: string; phase: ModelPhase }) =>
      apiClient.transitionPhase(modelId, phase),
    onSuccess: (data) => {
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.detail(data.modelId) })
      queryClient.invalidateQueries({ queryKey: modelQueryKeys.lists() })
    },
  })
}

/**
 * Refetch models list
 */
export function useRefreshModels() {
  const queryClient = useQueryClient()

  return async () => {
    await queryClient.refetchQueries({ queryKey: modelQueryKeys.lists() })
  }
}