import { existsSync } from 'node:fs'
import { readFile } from 'node:fs/promises'
import { resolve } from 'node:path'

/** 生产构建只替换连接配置，保留运行时 JSON 中的 GIS/模型参数。 */
export function productionRuntimeConfig(raw, env) {
    const keys = ['VITE_COCKPIT_DATA_SOURCE', 'VITE_COCKPIT_API_BASE_URL', 'VITE_COCKPIT_WS_URL']
    for (const key of keys) {
        if (typeof env[key] !== 'string' || !env[key].trim()) throw new Error('缺少生产环境变量：' + key)
    }
    const imageBase = typeof env.VITE_APP_MINIO_BASE_URL === 'string' && env.VITE_APP_MINIO_BASE_URL.trim()
        ? env.VITE_APP_MINIO_BASE_URL.trim() : '/minio/pipe/'
    try {
        const imageUrl = new URL(imageBase, 'http://runtime-image-config.invalid/')
        const publicPath = /^https?:\/\//i.test(imageBase) || (imageBase.startsWith('/') && !imageBase.startsWith('//'))
        if (!publicPath || !['http:', 'https:'].includes(imageUrl.protocol) || imageUrl.username || imageUrl.password || imageUrl.search || imageUrl.hash) throw new Error()
    } catch {
        throw new Error('生产图片访问基址必须是无凭据或签名参数的公开地址或同源路径')
    }
    return {
        ...raw,
        dataSource: env.VITE_COCKPIT_DATA_SOURCE,
        api: { ...raw.api, baseUrl: env.VITE_COCKPIT_API_BASE_URL },
        ws: { ...raw.ws, url: env.VITE_COCKPIT_WS_URL },
        images: { baseUrl: imageBase },
    }
}

/** 生产配置来自可复现的部署模板，绝不复制本机 public/cockpit/config.json。 */
export default function cockpitEnvPlugin() {
    let config
    const readTemplate = async () => productionRuntimeConfig(
        JSON.parse(await readFile(resolve(config.root, 'deploy/cockpit.config.json'), 'utf8')),
        config.env,
    )
    return {
        name: 'cockpit-environment-config',
        configResolved(resolved) { config = resolved },
        configureServer(server) {
            // 干净检出也有完整地图配置；已有本机 JSON 时仍遵循原覆盖规则。
            server.middlewares.use('/cockpit/config.json', async (req, res, next) => {
                if (existsSync(resolve(config.publicDir, 'cockpit/config.json'))) return next()
                try {
                    const raw = await readTemplate()
                    res.setHeader('Content-Type', 'application/json; charset=utf-8')
                    res.setHeader('Cache-Control', 'no-cache')
                    res.end(JSON.stringify(raw))
                } catch (error) { next(error) }
            })
        },
        async generateBundle() {
            this.emitFile({
                type: 'asset',
                fileName: 'cockpit/config.json',
                source: JSON.stringify(await readTemplate(), null, 2) + '\n',
            })
        },
    }
}