function text(value) { return String(value ?? '').trim(); }
function number(value, fallback = 0) { const parsed = Number(value); return Number.isFinite(parsed) ? parsed : fallback; }
function dateValue(value) {
  const raw = text(value);
  if (!/^\d{4}-\d{1,2}-\d{1,2}(?:[ T]\d{1,2}:\d{2}(?::\d{2}(?:\.\d+)?)?)?/.test(raw)) return null;
  const normalized = raw.replace(/^(\d{4})-(\d)(?=-)/, '$1-0$2').replace(/-(\d)(?=[ T])/, '-0$1').replace(' ', 'T');
  const date = new Date(normalized + (normalized.includes('T') ? '+08:00' : 'T00:00:00+08:00'));
  return Number.isNaN(date.getTime()) ? null : { __type: 'Date', iso: date.toISOString() };
}
function setIf(body, key, value) { if (value !== null && value !== undefined && value !== '') body[key] = value; }

const legacyAddonFields = {
  53: ['kcid','scid','xxcs','yhid','jrscb'],
  54: ['pl','bxrq','dslx','dszt','fxpl','jffs','jssj','kcid','kssj','plxm','scsj','sdsd','szmd','szyh','yysj','yykcid'],
  56: ['pl','con','djq','ygg','dqrq','dsid','fxrl','xxqs','szmdid','userId','learned'],
  58: ['yxx','cksl','kcid','syjd','yhid'],
  59: ['pf','jffs','jsmz','kcid','kclx','kcmc','kzsj','pjnr','pldp','xymz','yyds','plpjsj','szmdid'],
  60: ['fxzt','kcid','plid','wcsj','yhid','kywrq','kywsj','xxjlid','orderId'],
  61: ['df','askid','wrong','userId','answerid','dontKnow','prevScore','totalScore'],
};
const numericAddonFields = new Set(['scid','xxcs','yhid@53','djq','ygg','userId@56','learned','yxx','cksl','pf','kcid@60','plid','yhid@60','xxjlid','orderId']);

function signatureValue(modelId, field, value) {
  return numericAddonFields.has(field) || numericAddonFields.has(`${field}@${modelId}`) ? number(value) : text(value);
}

function addonSignature(modelId, source) {
  return JSON.stringify(legacyAddonFields[modelId].map((field) => signatureValue(modelId, field, source[field])));
}

function commonBody(modelId, row, itemId) {
  const spec = specs[modelId];
  const generalId = number(row.GeneralID ?? row.generalId);
  const body = {
    company,
    sourceKey: `legacy:model:${modelId}:general:${generalId}`,
    generalId,
    itemId,
    modelId,
    nodeId: number(row.NodeID ?? row.nodeId, spec.nodeId),
    tableName: spec.tableName,
    title: text(row.Title ?? row.title),
    subtitle: text(row.Subtitle ?? row.subtitle),
    inputer: text(row.Inputer ?? row.inputer),
    topImg: text(row.TopImg ?? row.topImg),
    template: text(row.Template ?? row.template),
    hits: number(row.Hits ?? row.hits),
    status: 99,
  };
  const created = dateValue(row.CreateTime ?? row.createTime);
  if (created) { body.createTime = created; body.upDateTime = created; }
  return body;
}

function addonBody(modelId, row, itemId, generalId) {
  // Parse REST/SDK reserves the property name `id`. The physical legacy id is
  // assigned in one controlled SQL step after both objects exist.
  const body = { company, sourceKey: `legacy:model:${modelId}:general:${generalId}` };
  if (modelId === 53) Object.assign(body, {
    kcid: text(row.kcid), scid: number(row.scid), xxcs: number(row.xxcs), yhid: number(row.yhid), jrscb: text(row.jrscb),
  });
  if (modelId === 54) for (const field of ['pl','bxrq','dslx','dszt','fxpl','jffs','jssj','kcid','kssj','plxm','scsj','sdsd','szmd','szyh','yysj','yykcid']) body[field] = text(row[field]);
  if (modelId === 56) Object.assign(body, {
    pl: text(row.pl), con: text(row.con), djq: number(row.djq), ygg: number(row.ygg), dqrq: text(row.dqrq),
    dsid: text(row.dsid), fxrl: text(row.fxrl), xxqs: text(row.xxqs), szmdid: text(row.szmdid),
    userId: number(row.UserID ?? row.userId), learned: number(row.learned),
  });
  if (modelId === 58) Object.assign(body, {
    yxx: number(row.yxx), cksl: number(row.cksl), kcid: text(row.kcid), syjd: text(row.syjd), yhid: text(row.yhid),
  });
  if (modelId === 59) {
    for (const field of ['jffs','jsmz','kcid','kclx','kcmc','kzsj','pjnr','pldp','xymz','yyds','plpjsj','szmdid']) body[field] = text(row[field]);
    setIf(body, 'pf', row.pf === null || row.pf === '' ? null : number(row.pf));
    body.legacyGeneralId = generalId;
    body.studentName = text(row.Title ?? row.title);
    body.coachName = text(row.Inputer ?? row.inputer);
    body.courseName = text(row.kcmc ?? row.Subtitle ?? row.subtitle);
    body.storeId = number(row.szmdid);
    const lessonAt = dateValue(row.plpjsj) || dateValue(row.CreateTime ?? row.createTime);
    const sourceCreatedAt = dateValue(row.CreateTime ?? row.createTime);
    if (lessonAt) body.lessonAt = lessonAt;
    if (sourceCreatedAt) body.sourceCreatedAt = sourceCreatedAt;
  }
  if (modelId === 60) Object.assign(body, {
    fxzt: text(row.fxzt), kcid: number(row.kcid), plid: number(row.plid), wcsj: text(row.wcsj), yhid: number(row.yhid),
    kywrq: text(row.kywrq), kywsj: text(row.kywsj), xxjlid: number(row.xxjlid), orderId: number(row.orderId),
  });
  if (modelId === 61) Object.assign(body, {
    df: text(row.df), askid: text(row.askid), wrong: text(row.wrong), userId: text(row.UserID ?? row.userId),
    answerid: text(row.answerid), dontKnow: text(row.dontKnow), prevScore: text(row.prev_score ?? row.prevScore), totalScore: text(row.totalScore),
  });
  return body;
}


export function projectionFor(companyValue, specsValue) { company=companyValue; specs=specsValue; return {commonBody,addonBody,legacyAddonFields,signatureValue}; }
let company, specs;
export { commonBody, addonBody, legacyAddonFields, signatureValue };