// Backend client for Milestone 2 real inference. Falls back to the labeled
// client-side mock (mockData.runDetectability) when the backend is unreachable,
// so the static site still works offline / in a pure-demo deployment.
import { parseSequences } from './parseSequences'
import {
  runDetectability,
  runTraining,
  runBioactivityPeptides,
  runAllergenOrigin,
  type DetectabilityRow,
  type BioactivityRow,
  type AllergenRow,
  type TrainingConfig,
  type TrainingResult,
} from '../data/mockData'
import type { RealModel } from '../data/models'

const API_BASE = import.meta.env.VITE_API_BASE ?? '/api'

export interface PredictOutcome {
  rows: DetectabilityRow[]
  live: boolean // true = real backend inference; false = offline mock fallback
  calibrated: boolean // backend-reported; only meaningful when live
}

interface PredictResponse {
  model: string
  calibrated: boolean
  results: {
    peptide: string
    length: number
    score: number
    prediction: string
    inTraining?: 'positive' | 'negative' | null
  }[]
  flags: string[]
}

/**
 * Score peptides with a model. Tries the backend first; on any network/HTTP
 * error returns the deterministic mock so the UI degrades gracefully.
 */
export async function predictDetectability(
  input: string,
  model: RealModel,
): Promise<PredictOutcome> {
  const peptides = parseSequences(input).map((p) => p.seq)
  const label = `${model.code} · ${model.species}`
  try {
    const res = await fetch(`${API_BASE}/predict`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ peptides, modelCode: model.code }),
    })
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    const data: PredictResponse = await res.json()
    const rows: DetectabilityRow[] = data.results.map((r) => ({
      peptide: r.peptide,
      length: r.length,
      score: r.score,
      prediction: r.prediction === 'Detectable' ? 'Detectable' : 'Not detectable',
      model: label,
      inTraining: r.inTraining ?? null,
    }))
    return { rows, live: true, calibrated: data.calibrated }
  } catch {
    // Backend down / not deployed → labeled illustrative mock.
    return { rows: runDetectability(input, model), live: false, calibrated: false }
  }
}

// ---------------------------------------------------------------- bioactivity screening
export interface BioactivityOutcome {
  rows: BioactivityRow[]
  live: boolean
}
export interface AllergenOutcome {
  rows: AllergenRow[]
  live: boolean
}

interface BioRespPeptide {
  peptide: string
  bioactivities: string
  sources: string
  ige_epitope: string
}
interface BioRespProtein {
  protein: string
  is_recognized_allergen: string
  allergen_name: string
  organism: string
  source: string
}

/** Screen peptides for bioactivity/cytotoxicity + IgE-epitope retention (Q2). */
export async function screenBioactivityPeptides(input: string): Promise<BioactivityOutcome> {
  const sequences = parseSequences(input).map((p) => p.seq)
  try {
    const res = await fetch(`${API_BASE}/bioactivity`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ mode: 'peptides', sequences }),
    })
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    const data: BioRespPeptide[] = await res.json()
    const rows: BioactivityRow[] = data.map((r) => ({
      peptide: r.peptide,
      bioactivities: r.bioactivities,
      sources: r.sources,
      igeEpitope: r.ige_epitope === 'yes',
    }))
    return { rows, live: true }
  } catch {
    return { rows: runBioactivityPeptides(input), live: false }
  }
}

/** Screen proteins for allergen origin, recognized-allergen protein match (Q1). */
export async function screenAllergenOrigin(input: string): Promise<AllergenOutcome> {
  const sequences = parseSequences(input).map((p) => p.seq)
  try {
    const res = await fetch(`${API_BASE}/bioactivity`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ mode: 'proteins', sequences }),
    })
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    const data: BioRespProtein[] = await res.json()
    const rows: AllergenRow[] = data.map((r) => ({
      protein: r.protein,
      isAllergen: r.is_recognized_allergen === 'yes',
      allergenName: r.allergen_name,
      organism: r.organism,
      source: r.source,
    }))
    return { rows, live: true }
  } catch {
    return { rows: runAllergenOrigin(input), live: false }
  }
}

export interface TrainOutcome {
  result: TrainingResult
  live: boolean // true = real backend training; false = offline mock fallback
  downloadUrl: string | null // GET to fetch the trained joblib (live only)
  dataUrl: string | null // GET to fetch the processed dataset CSV (live only)
  species?: string
  error?: string // set when the backend rejected the request (e.g. unsupported tax id)
}

const sleep = (ms: number) => new Promise((r) => setTimeout(r, ms))

/**
 * Train a detectability model from a peptide list. Submits an async job, polls to
 * completion, and maps to TrainingResult. On any network/HTTP error falls back to the
 * deterministic client-side mock so the static demo still works offline.
 */
export async function trainDetectability(
  input: string,
  taxId: string,
  cfg: TrainingConfig,
): Promise<TrainOutcome> {
  const peptides = parseSequences(input).map((p) => p.seq)
  try {
    const res = await fetch(`${API_BASE}/train`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ peptides, taxId, config: cfg }),
    })
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    const { jobId } = (await res.json()) as { jobId: string }

    // poll (cap ~2 min at 1.5 s intervals)
    for (let i = 0; i < 80; i++) {
      await sleep(1500)
      const s = await fetch(`${API_BASE}/train/${jobId}`)
      if (!s.ok) throw new Error(`HTTP ${s.status}`)
      const job = await s.json()
      if (job.status === 'done') {
        return {
          result: job.result as TrainingResult,
          live: true,
          downloadUrl: `${API_BASE}/train/${jobId}/model`,
          dataUrl: `${API_BASE}/train/${jobId}/data`,
          species: job.result.species,
        }
      }
      if (job.status === 'error') {
        // A rejected request (bad tax id, unmapped peptides) is a real answer, not a
        // reason to silently show fake numbers, surface it with the mock as preview.
        return {
          result: runTraining(input, taxId + JSON.stringify(cfg)),
          live: false,
          downloadUrl: null,
          dataUrl: null,
          error: job.error as string,
        }
      }
    }
    throw new Error('training timed out')
  } catch {
    // Backend down / not deployed → labeled illustrative mock.
    return {
      result: runTraining(input, taxId + JSON.stringify(cfg)),
      live: false,
      downloadUrl: null,
      dataUrl: null,
    }
  }
}

// ---------------------------------------------------------------- protein digestibility
export interface Enzyme {
  key: string
  label: string
}

// Fallback enzyme list so the page still renders if the backend is unreachable (the real
// list comes from GET /api/enzymes, sourced from hydropd.api.available_enzymes()).
const FALLBACK_ENZYMES: Enzyme[] = [
  { key: 'trypsin', label: 'Trypsin' },
  { key: 'chymotrypsin', label: 'Chymotrypsin' },
  { key: 'pepsin_ph1.3', label: 'Pepsin pH1.3' },
  { key: 'pepsin_ph>2', label: 'Pepsin pH >2' },
  { key: 'subtilisin', label: 'Subtilisin' },
  { key: 'papain', label: 'Papain' },
  { key: 'thermolysin', label: 'Thermolysin' },
  { key: 'proteinase_k', label: 'Proteinase K' },
]

export async function fetchEnzymes(): Promise<Enzyme[]> {
  try {
    const res = await fetch(`${API_BASE}/enzymes`)
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    return (await res.json()) as Enzyme[]
  } catch {
    return FALLBACK_ENZYMES
  }
}

export interface DigestSummaryRow {
  enzyme: string
  enzyme_key: string
  candidate_set: number
  functional_set: number
  detected_functional_set?: number
  combined_all_models?: number
}

export interface DigestTables {
  candidate: Record<string, string | number>[]
  candidate_total: number
  functional: Record<string, string | number>[]
  functional_total: number
  detected: Record<string, string | number>[]
  detected_total: number
  det_cols: string[]
}

export interface DigestResult {
  summary: DigestSummaryRow[]
  summaryColumns: string[]
  models: string[]
  calibrated: Record<string, boolean>
  multi: boolean
  threshold: number
  display: Record<string, DigestTables>
  nProteins: number
  zipName: string
}

export interface DigestOutcome {
  result: DigestResult | null
  live: boolean
  zipUrl: string | null
  error?: string
}

/**
 * Run a protein-digestibility screen. Submits an async job, polls to completion (heavy: digestion
 * + functionality lookup + per-model detectability), and returns the ranked summary + a ZIP URL.
 * On any network/HTTP error returns a null result flagged offline so the page degrades gracefully.
 */
export async function computeDigestibility(
  proteins: string,
  enzymes: string[],
  models: string[],
  threshold: number,
): Promise<DigestOutcome> {
  try {
    const res = await fetch(`${API_BASE}/digestibility`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ proteins, enzymes, models, threshold }),
    })
    if (!res.ok) throw new Error(`HTTP ${res.status}`)
    const { jobId } = (await res.json()) as { jobId: string }

    // poll up to ~10 min at 2.5 s intervals (a full all-enzyme, multi-model run is slow)
    for (let i = 0; i < 240; i++) {
      await sleep(2500)
      const s = await fetch(`${API_BASE}/digestibility/${jobId}`)
      if (!s.ok) throw new Error(`HTTP ${s.status}`)
      const job = await s.json()
      if (job.status === 'done') {
        return {
          result: job.result as DigestResult,
          live: true,
          zipUrl: `${API_BASE}/digestibility/${jobId}/zip`,
        }
      }
      if (job.status === 'error') {
        return { result: null, live: false, zipUrl: null, error: job.error as string }
      }
    }
    throw new Error('digestibility timed out')
  } catch (e) {
    return { result: null, live: false, zipUrl: null, error: (e as Error).message }
  }
}