/**
 * fun 标签：img-cropping — 按正方形区域居中裁剪图片并保存
 *
 * 入参（inVars 顺序）：
 * - imagePath：源图片路径（相对当前流程目录或绝对路径）
 * - savePath：输出路径（相对流程目录或绝对路径）
 * - squareSpec：边长规则 [scale, 轴]：
 *   - [0.8, "w"] / "0.8,w" / "[0.8,w]"：边长 = 图片宽度 × 0.8
 *   - [1, "h"] / "1,h"：边长 = 图片高度 × 1
 *   轴：w / width / 宽；h / height / 高
 *
 * 若 scale×参照边 大于 min(宽,高)，会夹紧到 min(宽,高)。
 */

const path = require('path')
const fs = require('fs')
const { spawnSync } = require('child_process')
const { getPythonExeFromConfig } = require('../../../../python-exe-from-config.js')

const tagName = 'img-cropping'

const configPath = process.env.STATIC_ROOT
  ? path.join(path.dirname(path.resolve(process.env.STATIC_ROOT)), 'config.js')
  : path.join(__dirname, '..', '..', '..', '..', '..', 'config.js')
const config = fs.existsSync(configPath) ? require(configPath) : {}
const projectRoot = (config.projectRoot && fs.existsSync(config.projectRoot))
  ? config.projectRoot
  : path.dirname(path.resolve(configPath))
const squareCropScriptPath = path.join(projectRoot, 'python', 'scripts', 'img-crop-square-center.py')

function buildAbsolutePath (p, folderPath) {
  if (p == null || p === '') return null
  const s = typeof p === 'string' ? p.trim() : String(p)
  if (!s) return null
  if (path.isAbsolute(s) || /^[A-Za-z]:/.test(s)) return path.normalize(s)
  return folderPath ? path.join(folderPath, s) : path.resolve(projectRoot, s)
}

/** @returns {{ scale: number, axis: 'w'|'h' } | { error: string }} */
function parseSquareSpec (raw) {
  if (raw == null) return { error: 'squareSpec 为空' }

  if (Array.isArray(raw)) {
    if (raw.length < 2) return { error: 'squareSpec 数组须为 [scale, 轴]，如 [0.8, "w"]' }
    const scale = Number(raw[0])
    const axis = normalizeAxis(raw[1])
    if (Number.isNaN(scale) || scale <= 0) return { error: 'squareSpec 中 scale 须为大于 0 的数字' }
    if (!axis) return { error: 'squareSpec 中轴须为 w 或 h（宽/高）' }
    return { scale, axis }
  }

  const str = typeof raw === 'string' ? raw.trim() : String(raw).trim()
  if (!str) return { error: 'squareSpec 为空字符串' }

  try {
    const j = JSON.parse(str)
    if (Array.isArray(j) && j.length >= 2) return parseSquareSpec(j)
  } catch (_) { /* 非 JSON */ }

  const inner = str.startsWith('[') && str.endsWith(']') ? str.slice(1, -1).trim() : str
  const parts = inner.split(',').map((s) => s.trim().replace(/^["']|["']$/g, ''))
  if (parts.length < 2) return { error: 'squareSpec 格式须为 [scale,轴] 或 "scale,轴"，如 [0.8,w] 或 1,h' }
  const scale = Number(parts[0])
  const axis = normalizeAxis(parts[1])
  if (Number.isNaN(scale) || scale <= 0) return { error: 'scale 须为大于 0 的数字' }
  if (!axis) return { error: '轴须为 w 或 h' }
  return { scale, axis }
}

function normalizeAxis (v) {
  if (v == null) return null
  const a = String(v).trim().toLowerCase()
  if (a === 'w' || a === 'width' || a === '宽') return 'w'
  if (a === 'h' || a === 'height' || a === '高') return 'h'
  return null
}

/**
 * @param {{ imagePath: string, squareSpec: string|any[], savePath: string, folderPath?: string }} input
 */
async function executeImgCropping ({ imagePath, squareSpec, savePath, folderPath }) {
  if (imagePath == null || String(imagePath).trim() === '') {
    return { success: false, error: 'img-cropping 缺少 imagePath（inVars[0]）' }
  }
  if (savePath == null || String(savePath).trim() === '') {
    return { success: false, error: 'img-cropping 缺少 savePath（inVars[1]）' }
  }
  if (squareSpec === undefined || squareSpec === null || squareSpec === '') {
    return { success: false, error: 'img-cropping 缺少 squareSpec（inVars[2]，如 [0.8,"w"]）' }
  }

  const spec = parseSquareSpec(squareSpec)
  if (spec.error) return { success: false, error: `img-cropping squareSpec 无效: ${spec.error}` }

  const absIn = buildAbsolutePath(String(imagePath).trim(), folderPath)
  const absOut = buildAbsolutePath(String(savePath).trim(), folderPath)
  if (!absIn || !absOut) return { success: false, error: 'img-cropping 路径无效' }
  if (!fs.existsSync(absIn)) return { success: false, error: `img-cropping 源文件不存在: ${absIn}` }
  if (!fs.existsSync(squareCropScriptPath)) {
    return { success: false, error: `脚本不存在: ${squareCropScriptPath}` }
  }

  const pythonExe = getPythonExeFromConfig(config)
  const r = spawnSync(
    pythonExe,
    [squareCropScriptPath, absIn, absOut, String(spec.scale), spec.axis],
    {
      encoding: 'utf-8',
      timeout: 60000,
      cwd: projectRoot
    }
  )

  const combined = ((r.stdout || '') + '\n' + (r.stderr || '')).trim()
  if (r.status !== 0) {
    return { success: false, error: combined || 'img-cropping 裁剪失败' }
  }

  let meta = {}
  const lines = (r.stdout || '').split(/\r?\n/).map((l) => l.trim()).filter(Boolean)
  const jsonLine = lines.filter((l) => l.startsWith('{')).pop()
  if (jsonLine) {
    try {
      meta = JSON.parse(jsonLine)
    } catch (_) {}
  }
  if (!meta.success) {
    return { success: false, error: meta.error || combined || 'img-cropping 未返回成功' }
  }

  return {
    success: true,
    path: absOut,
    value: absOut,
    result: absOut,
    crop: { x: meta.x, y: meta.y, side: meta.side, sourceWidth: meta.width, sourceHeight: meta.height }
  }
}

module.exports = { tagName, executeImgCropping, parseSquareSpec }