import {
  ALIYUN_ACCESS_KEY_ID,
  ALIYUN_ACCESS_KEY_SECRET,
  ALIYUN_SECURITY_TOKEN,
  ALIYUN_STS_URL,
  IMM_REGION,
  OSS_BUCKET,
  OSS_KEY_PREFIX,
  OSS_REGION,
  SEGMENT_API_BASE,
  SEGMENT_API_TOKEN,
  SEGMENT_TRANSPORT
} from './segmentApi.js'
import {
  ossPostObjectFromLocalFilePath,
  ossPresignedObjectUrl,
  rpcIvpdSegmentImage,
  looksLikeBareOssEndpointUrl
} from './aliyunPortraitUni.js'

function uniRequest(options) {
  return new Promise((resolve, reject) => {
    uni.request({
      ...options,
      success: (r) => {
        if (r.statusCode >= 200 && r.statusCode < 300) {
          resolve(r)
        } else {
          const msg =
            (typeof r.data === 'object' && r.data && (r.data.Message || r.data.message)) ||
            (typeof r.data === 'string' ? r.data : '') ||
            `HTTP ${r.statusCode}`
          reject(new Error(msg))
        }
      },
      fail: (e) => reject(new Error(e.errMsg || '网络请求失败'))
    })
  })
}

/** 内层 Promise 长期无回调时强制失败（避免一直「正在识别」） */
function raceWithTimeout(promise, ms, errMsg) {
  return new Promise((resolve, reject) => {
    const t = setTimeout(() => reject(new Error(errMsg)), ms)
    Promise.resolve(promise).then(
      (v) => {
        clearTimeout(t)
        resolve(v)
      },
      (e) => {
        clearTimeout(t)
        reject(e)
      }
    )
  })
}

function normalizeStsPayload(raw) {
  if (!raw || typeof raw !== 'object') {
    return null
  }
  if (raw.Credentials) {
    const c = raw.Credentials
    return {
      accessKeyId: c.AccessKeyId,
      accessKeySecret: c.AccessKeySecret,
      securityToken: c.SecurityToken || undefined,
      expiration: c.Expiration
    }
  }
  if (raw.accessKeyId && raw.accessKeySecret) {
    return {
      accessKeyId: raw.accessKeyId,
      accessKeySecret: raw.accessKeySecret,
      securityToken: raw.securityToken || undefined,
      expiration: raw.expiration
    }
  }
  return null
}

async function fetchStsCredentials() {
  const url = (ALIYUN_STS_URL || '').trim()
  if (!url) {
    return null
  }
  const res = await uniRequest({ url, method: 'GET', timeout: 30000 })
  const data = typeof res.data === 'string' ? JSON.parse(res.data) : res.data
  const cred = normalizeStsPayload(data)
  if (!cred || !cred.accessKeyId) {
    throw new Error('STS 地址返回格式不正确（需 Credentials 或 accessKeyId/accessKeySecret）')
  }
  return cred
}

/** 开发直配 AK，或 STS 拉取 */
function getCredentialsFromConfig() {
  const id = (ALIYUN_ACCESS_KEY_ID || '').trim()
  const sec = (ALIYUN_ACCESS_KEY_SECRET || '').trim()
  const token = (ALIYUN_SECURITY_TOKEN || '').trim()
  if (id && sec) {
    return {
      accessKeyId: id,
      accessKeySecret: sec,
      securityToken: token || undefined
    }
  }
  return null
}

async function resolveCredentials() {
  const fromFile = getCredentialsFromConfig()
  if (fromFile) {
    return fromFile
  }
  const url = (ALIYUN_STS_URL || '').trim()
  if (!url) {
    throw new Error('请配置 ALIYUN_ACCESS_KEY_ID/SECRET（开发）或 ALIYUN_STS_URL（生产）')
  }
  return fetchStsCredentials()
}

function canUseDirectAliyunClient() {
  const bucket = (OSS_BUCKET || '').trim()
  const hasAk =
    !!(ALIYUN_ACCESS_KEY_ID || '').trim() && !!(ALIYUN_ACCESS_KEY_SECRET || '').trim()
  const hasStsUrl = !!(ALIYUN_STS_URL || '').trim()
  return !!(bucket && (hasAk || hasStsUrl))
}

/**
 * @returns {'direct' | 'backend'}
 */
function resolveSegmentTransport() {
  const raw = String(SEGMENT_TRANSPORT == null ? 'auto' : SEGMENT_TRANSPORT)
    .trim()
    .toLowerCase()
  if (raw === 'backend' || raw === 'proxy' || raw === 'server') {
    return 'backend'
  }
  if (raw === 'direct' || raw === 'aliyun' || raw === 'client' || raw === 'oss') {
    if (!canUseDirectAliyunClient()) {
      throw new Error(
        'SEGMENT_TRANSPORT 为 direct/aliyun/client/oss 时需配置 OSS_BUCKET 以及（ALIYUN_ACCESS_KEY_ID+SECRET 或 ALIYUN_STS_URL）'
      )
    }
    return 'direct'
  }
  return canUseDirectAliyunClient() ? 'direct' : 'backend'
}

/**
 * 凭证 → OSS PostObject → 签名 GET URL → IVPD SegmentImage（Url）→ downloadFile
 */
async function segmentViaOssIvpd(filePath) {
  const bucket = (OSS_BUCKET || '').trim()
  if (!bucket) {
    throw new Error('请在 config/segmentApi.js 配置 OSS_BUCKET')
  }

  const cred = await resolveCredentials()

  const ext = /\.png$/i.test(String(filePath || '')) ? 'png' : 'jpg'
  const base = `${Date.now()}_${Math.random().toString(36).slice(2, 10)}`
  const prefix = OSS_KEY_PREFIX.replace(/^\/+/, '')
  const objectKeyIn = `${prefix}${base}.${ext}`

  await ossPostObjectFromLocalFilePath({
    bucket,
    ossRegionId: OSS_REGION,
    accessKeyId: cred.accessKeyId,
    accessKeySecret: cred.accessKeySecret,
    securityToken: cred.securityToken,
    objectKey: objectKeyIn,
    filePath
  })

  const imageUrlForSeg = await ossPresignedObjectUrl({
    bucket,
    ossRegionId: OSS_REGION,
    accessKeyId: cred.accessKeyId,
    accessKeySecret: cred.accessKeySecret,
    securityToken: cred.securityToken,
    objectKey: objectKeyIn,
    expiresSec: 3600
  })

  const ivpdRegion = (IMM_REGION || '').trim() || String(OSS_REGION || '').replace(/^oss-/i, '')

  const outUrl = await rpcIvpdSegmentImage({
    imageUrl: imageUrlForSeg,
    accessKeyId: cred.accessKeyId,
    accessKeySecret: cred.accessKeySecret,
    securityToken: cred.securityToken,
    regionId: ivpdRegion
  })

  return raceWithTimeout(
    new Promise((res, rej) => {
      uni.downloadFile({
        url: outUrl,
        timeout: 120000,
        success: (dr) => {
          if (dr.statusCode !== 200 || !dr.tempFilePath) {
            rej(new Error('下载分割结果失败'))
            return
          }
          res({ kind: 'cutout', localPath: dr.tempFilePath })
        },
        fail: (e) => {
          const raw = e.errMsg || '未知错误'
          const needDomainHint =
            looksLikeBareOssEndpointUrl(raw) ||
            (/^https?:\/\//i.test(String(raw).trim()) && String(raw).includes('aliyuncs'))
          const extra = needDomainHint
            ? '（若仅为 URL：请在 manifest → networkSecurity.domainWhiteList 中加入下载域名并重编译。）'
            : ''
          rej(new Error(`下载分割结果失败：${raw}${extra}`))
        }
      })
    }),
    125000,
    '下载分割结果超时'
  )
}

/**
 * 方案二：自建 Node 代理（server/index.js）
 */
function segmentViaProxy(filePath) {
  const base = (SEGMENT_API_BASE || '').trim().replace(/\/+$/, '')
  if (!base) {
    return Promise.reject(
      new Error(
        '缺少 SEGMENT_API_BASE：HTTP/后端抠图需要填写根地址（POST {BASE}/segment）。若使用客户端直连阿里云，请配置 OSS_BUCKET 与 AK 或 STS，并将 SEGMENT_TRANSPORT 设为 auto 或 direct。'
      )
    )
  }
  const url = `${base}/segment`

  return new Promise((resolve, reject) => {
    uni.uploadFile({
      url,
      filePath,
      name: 'image',
      timeout: 120000,
      header: SEGMENT_API_TOKEN ? { 'x-laser-token': SEGMENT_API_TOKEN } : {},
      success: (res) => {
        if (res.statusCode !== 200) {
          reject(new Error(typeof res.data === 'string' ? res.data : `HTTP ${res.statusCode}`))
          return
        }
        let body
        try {
          body = typeof res.data === 'string' ? JSON.parse(res.data) : res.data
        } catch (e) {
          reject(new Error('代理返回非 JSON'))
          return
        }
        if (!body || body.ok !== true || !body.imageUrl) {
          reject(new Error((body && body.error) || '抠图失败'))
          return
        }
        uni.downloadFile({
          url: body.imageUrl,
          timeout: 120000,
          success: (dr) => {
            if (dr.statusCode !== 200 || !dr.tempFilePath) {
              reject(new Error('下载分割结果失败'))
              return
            }
            resolve({ kind: 'cutout', localPath: dr.tempFilePath })
          },
          fail: (e) => reject(new Error(e.errMsg || 'downloadFile 失败'))
        })
      },
      fail: (e) => reject(new Error(e.errMsg || 'uploadFile 失败'))
    })
  })
}

/** 防止某一步网络/原生无回调导致一直转圈 */
function withTimeout(promise, ms, message) {
  let timer = null
  return new Promise((resolve, reject) => {
    timer = setTimeout(() => {
      timer = null
      reject(new Error(message))
    }, ms)
    promise.then(
      (v) => {
        if (timer != null) {
          clearTimeout(timer)
        }
        resolve(v)
      },
      (e) => {
        if (timer != null) {
          clearTimeout(timer)
        }
        reject(e)
      }
    )
  })
}

/**
 * 上传本地图并获取抠图结果本地路径。
 * 链路由 config/segmentApi.js 的 SEGMENT_TRANSPORT 决定：direct=客户端 OSS + IVPD SegmentImage；backend=HTTP 后端（契约同 server/index.js）；auto=能直连则直连否则走后端。
 */
export function segmentPortraitToLocal(filePath) {
  const transport = resolveSegmentTransport()
  const inner =
    transport === 'direct' ? segmentViaOssIvpd(filePath) : segmentViaProxy(filePath)
  return withTimeout(
    inner,
    240000,
    '智能抠图超时：请检查手机网络、OSS、IVPD 地域（IMM_REGION，如 cn-shanghai）、RAM 权限及 manifest 网络权限'
  )
}