import type { Context } from '@opentelemetry/api'
import { context } from '@opentelemetry/api'

const originalPromise = globalThis.Promise

class TraceContextPromise<T> extends Promise<T> {
  _context: Context

  constructor(
    executor: (resolve: (value: T | PromiseLike<T>) => void, reject: (reason?: any) => void) => void,
    ctx?: Context
  ) {
    const capturedContext = ctx || context.active()
    super((resolve, reject) => {
      context.with(capturedContext, () => {
        executor(
          (value) => context.with(capturedContext, () => resolve(value)),
          (reason) => context.with(capturedContext, () => reject(reason))
        )
      })
    })
    this._context = capturedContext
  }

  // 兼容 Promise.resolve/reject
  static resolve(): Promise<void>
  static resolve<T>(value: T | PromiseLike<T>): Promise<T>
  static resolve<T>(value: T | PromiseLike<T>, ctx?: Context): Promise<T>
  static resolve<T>(value?: T | PromiseLike<T>, ctx?: Context): Promise<T | void> {
    return new TraceContextPromise<T | void>((resolve) => resolve(value as T), ctx)
  }

  static reject<T = never>(reason?: any): Promise<T>
  static reject<T = never>(reason?: any, ctx?: Context): Promise<T> {
    return new TraceContextPromise<T>((_, reject) => reject(reason), ctx)
  }

  static all<T>(values: (T | PromiseLike<T>)[]): Promise<T[]> {
    // 尝试从缓存获取 context
    let capturedContext = context.active()
    const newValues = values.map((v) => {
      if (v instanceof Promise && !(v instanceof TraceContextPromise)) {
        return new TraceContextPromise((resolve, reject) => v.then(resolve, reject), capturedContext)
      } else if (typeof v === 'function') {
        // 如果 v 是一个 Function，使用 context 传递 trace 上下文
        return (...args: any[]) => context.with(capturedContext, () => v(...args))
      } else {
        return v
      }
    })
    if (Array.isArray(values) && values.length > 0 && values[0] instanceof TraceContextPromise) {
      capturedContext = (values[0] as TraceContextPromise<any>)._context
    }
    return originalPromise.all(newValues) as Promise<T[]>
  }

  static race<T>(values: (T | PromiseLike<T>)[]): Promise<T> {
    const capturedContext = context.active()
    return new TraceContextPromise<T>((resolve, reject) => {
      originalPromise.race(values).then(
        (result) => context.with(capturedContext, () => resolve(result)),
        (err) => context.with(capturedContext, () => reject(err))
      )
    }, capturedContext)
  }

  static allSettled<T>(values: (T | PromiseLike<T>)[]): Promise<PromiseSettledResult<T>[]> {
    const capturedContext = context.active()
    return new TraceContextPromise<PromiseSettledResult<T>[]>((resolve, reject) => {
      originalPromise.allSettled(values).then(
        (result) => context.with(capturedContext, () => resolve(result)),
        (err) => context.with(capturedContext, () => reject(err))
      )
    }, capturedContext)
  }

  static any<T>(values: (T | PromiseLike<T>)[]): Promise<T> {
    const capturedContext = context.active()
    return new TraceContextPromise<T>((resolve, reject) => {
      originalPromise.any(values).then(
        (result) => context.with(capturedContext, () => resolve(result)),
        (err) => context.with(capturedContext, () => reject(err))
      )
    }, capturedContext)
  }
}

/**
 * 用 TraceContextPromise 替换全局 Promise
 */
export function instrumentPromises() {
  globalThis.Promise = TraceContextPromise as unknown as PromiseConstructor
}

/**
 * 恢复原生 Promise
 */
export function uninstrumentPromises() {
  globalThis.Promise = originalPromise
}