import { reactive, ref, type Ref } from 'vue'
import { ElMessage } from 'element-plus'
import { createResults } from './previewModel'
import type {
  GenerationState,
  PreviewItem,
  ProcessType,
  ResultItem,
  StructuredProcessOptions,
  UnstructuredProcessOptions,
} from './types'

interface GenerationBindings {
  previewItems: Ref<PreviewItem[]>
  processType: Ref<ProcessType>
  structuredOptions: Ref<StructuredProcessOptions>
  unstructuredOptions: Ref<UnstructuredProcessOptions>
  dirty: Ref<boolean>
}

export function useDataProcessGeneration(bindings: GenerationBindings) {
  const results = ref<ResultItem[]>([])
  const selectedResultId = ref<string | null>(null)
  const generation = reactive<GenerationState>({
    status: 'idle',
    progress: 0,
    message: '确认摘要后即可开始生成，过程中可查看实时进度。',
  })
  let generationTimer: ReturnType<typeof setInterval> | null = null

  function stopGenerationTimer() {
    if (generationTimer) clearInterval(generationTimer)
    generationTimer = null
  }

  function resetDownstream() {
    stopGenerationTimer()
    generation.status = 'idle'
    generation.progress = 0
    generation.message = '确认摘要后即可开始生成，过程中可查看实时进度。'
    results.value = []
    selectedResultId.value = null
  }

  function startGeneration() {
    stopGenerationTimer()
    generation.status = 'running'
    generation.progress = 0
    generation.message = '正在应用预览修改并生成标准化结果，请稍候。'

    generationTimer = setInterval(() => {
      generation.progress = Math.min(100, generation.progress + 8)
      if (generation.progress < 100) return

      stopGenerationTimer()
      generation.status = 'success'
      results.value = createResults(
        bindings.previewItems.value,
        bindings.processType.value === 'structured'
          ? bindings.structuredOptions.value
          : bindings.processType.value === 'unstructured'
            ? bindings.unstructuredOptions.value
            : undefined,
      )
      generation.message = `已完成 ${results.value.length.toLocaleString()} 条数据处理，可进入结果页检查。`
      selectedResultId.value = results.value[0]?.id ?? null
      bindings.dirty.value = true
      ElMessage.success('数据处理完成')
    }, 180)
  }

  function stopGeneration() {
    stopGenerationTimer()
    generation.status = 'failed'
    generation.message = '任务已停止，预览修改仍然保留，可以重新生成。'
  }

  function updateResultField(id: string, field: 'instruction' | 'input' | 'output', value: string) {
    const item = results.value.find((entry) => entry.id === id)
    if (!item) return
    item[field] = value
    const valid = item.instruction.trim() && item.output.trim()
    item.error = valid ? undefined : 'Instruction 和 Output 不能为空'
    const changed = item.instruction !== item.originalInstruction
      || item.input !== item.originalInput
      || item.output !== item.originalOutput
    item.status = item.error ? 'invalid' : changed ? 'modified' : 'valid'
    bindings.dirty.value = true
  }

  function restoreResult(id: string) {
    const item = results.value.find((entry) => entry.id === id)
    if (!item) return
    item.instruction = item.originalInstruction
    item.input = item.originalInput
    item.output = item.originalOutput
    item.error = undefined
    item.status = 'valid'
    bindings.dirty.value = true
  }

  function validateResults() {
    let firstInvalidId: string | null = null
    for (const item of results.value) {
      if (!item.instruction.trim() || !item.output.trim()) {
        item.error = 'Instruction 和 Output 不能为空'
        item.status = 'invalid'
        firstInvalidId ??= item.id
      }
    }
    if (firstInvalidId) selectedResultId.value = firstInvalidId
    return firstInvalidId == null
  }

  return {
    generation,
    results,
    selectedResultId,
    resetDownstream,
    restoreResult,
    startGeneration,
    stopGeneration,
    stopGenerationTimer,
    updateResultField,
    validateResults,
  }
}