import { clientSupports, normalizeSsCipher, type ExcludedNode, type NodeDto } from '@proxy-station/shared';
import type { ProfileIR } from '../ir.js';
import { surgeAiDns } from './surge-ai-dns.js';
import { surgeDeclaration, surgeParam, surgeValue as quoteName } from './surge-format.js';

export function surgeNodeLine(n: NodeDto): string {
  const parts: string[] = [];
  switch (n.protocol) {
    case 'vmess': {
      const verdict = clientSupports('surge', n);
      if (!verdict.ok) throw new Error(verdict.reason);
      parts.push('vmess', quoteName(n.server), String(n.port), `username=${n.uuid}`);
      if (n.network === 'ws') {
        parts.push('ws=true', `ws-path=${quoteName(n.wsPath || '/')}`);
        if (n.wsHost) parts.push(`ws-headers=${quoteName(`Host:${n.wsHost}`)}`);
      }
      if (n.tls) {
        parts.push('tls=true');
        if (n.sni) parts.push(`sni=${quoteName(n.sni)}`);
        if (n.skipCertVerify) parts.push('skip-cert-verify=true');
      }
      // alterId=0 的 AEAD 头必须显式打开，否则 Surge 连不上且症状隐晦
      parts.push('vmess-aead=true');
      if (n.security !== 'auto') parts.push(`encrypt-method=${normalizeSsCipher(n.security)}`);
      break;
    }
    case 'trojan': {
      parts.push('trojan', quoteName(n.server), String(n.port), `password=${quoteName(n.password || '')}`);
      if (n.network === 'ws') {
        parts.push('ws=true', `ws-path=${quoteName(n.wsPath || '/')}`);
        if (n.wsHost) parts.push(`ws-headers=${quoteName(`Host:${n.wsHost}`)}`);
      }
      if (n.sni) parts.push(`sni=${quoteName(n.sni)}`);
      if (n.skipCertVerify) parts.push('skip-cert-verify=true');
      break;
    }
    case 'shadowsocks': {
      parts.push('ss', quoteName(n.server), String(n.port), `encrypt-method=${quoteName(normalizeSsCipher(n.method || ''))}`, `password=${quoteName(n.password || '')}`);
      break;
    }
    case 'hysteria2': {
      parts.push('hysteria2', quoteName(n.server), String(n.port), `password=${quoteName(n.password || '')}`);
      if (n.sni) parts.push(`sni=${quoteName(n.sni)}`);
      // Surge 的 salamander 混淆参数名（sub-router 生产验证过）
      if (n.obfsType === 'salamander' && n.obfsPassword) parts.push(`salamander-password=${quoteName(n.obfsPassword)}`);
      if (n.downMbps) parts.push(`download-bandwidth=${n.downMbps}`);
      if (n.skipCertVerify) parts.push('skip-cert-verify=true');
      break;
    }
  }
  return `${surgeDeclaration(n.name)} = ${parts.join(', ')}`;
}

export interface SurgeOutput {
  content: string;
  excluded: ExcludedNode[];
}

export function generateSurge(ir: ProfileIR, opts: { selfUrl: string }): SurgeOutput {
  const dns = surgeAiDns(ir);
  const excluded: ExcludedNode[] = [];
  const usable = ir.nodes.filter((n) => {
    const verdict = clientSupports('surge', n);
    if (!verdict.ok) excluded.push({ name: n.name, reason: verdict.reason! });
    return verdict.ok;
  });
  const usableNames = new Set(usable.map((n) => n.name));

  const lines: string[] = [];
  lines.push(`#!MANAGED-CONFIG ${opts.selfUrl} interval=86400 strict=true`);
  lines.push('# 由 Proxy Station 生成，请勿手动编辑（改动会在下次更新时被覆盖）');
  lines.push('');
  lines.push('[General]');
  lines.push(dns.general);

  lines.push('', '[Proxy]');
  for (const n of usable) lines.push(surgeNodeLine(n));

  lines.push('', '[Proxy Group]');
  for (const g of ir.groups) {
    const parts: string[] = [g.type];
    const memberNames = g.members
      .filter((m) => m.kind !== 'node' || usableNames.has(m.name))
      .map((m) => quoteName(m.name));
    if (g.filterRegex) {
      parts.push(...g.members.filter((m) => m.kind !== 'group' && (m.kind !== 'node' || usableNames.has(m.name))).map((m) => quoteName(m.name)));
      // 按名称正则动态筛选：节点来源可以是全部节点，也可以是另一个组
      if (g.includeAllNodes) {
        parts.push('include-all-proxies=true');
      }
      const sources = g.members.filter((m) => m.kind === 'group').map((m) => m.name);
      if (sources.length) parts.push(`include-other-group=${quoteName(sources.join(','))}`);
      parts.push(`policy-regex-filter=${quoteName(g.filterRegex)}`);
    } else if (g.includeAllNodes) {
      // 「全部节点」组：显式展开当前启用且 Surge 支持的节点
      parts.push(...[...new Set([...g.members.filter((m) => m.kind !== 'node' || usableNames.has(m.name)).map((m) => m.name), ...usable.map((n) => n.name)])].map(quoteName));
      if (usable.length === 0) parts.push('DIRECT');
    } else {
      parts.push(...(memberNames.length ? memberNames : ['DIRECT']));
    }
    if (g.type !== 'select') {
      // Surge uses per-node test-url or General.proxy-test-url, never group url=.
      if (g.interval) parts.push(`interval=${g.interval}`);
      if (g.type === 'url-test' && g.tolerance !== null) parts.push(`tolerance=${g.tolerance}`);
    }
    lines.push(`${surgeDeclaration(g.name)} = ${parts.join(', ')}`);
  }

  lines.push('', '[Rule]');
  lines.push(...dns.rules);
  for (const r of ir.rules.filter((r) => r.type !== 'FINAL')) {
    const value = r.ruleset ? r.ruleset.surgeUrl : r.value;
    const encoded = ['AND', 'OR', 'NOT'].includes(r.type) ? value : quoteName(value || '');
    lines.push([r.type, encoded, quoteName(r.policy), ...r.params.map(surgeParam)].join(','));
  }
  const final = ir.rules.find((r) => r.type === 'FINAL');
  lines.push(['FINAL', quoteName(final?.policy ?? 'DIRECT'), ...(final?.params ?? []).map(surgeParam)].join(','));

  for (const section of ['Host', 'URL Rewrite', 'Header Rewrite', 'MITM', 'Script']) {
    const content = section === 'Host' ? dns.host : ir.sections[section];
    if (content) {
      lines.push('', `[${section}]`, content);
    }
  }

  return { content: lines.join('\n') + '\n', excluded };
}