common.ts

export const queryEnv = async (
	envKey: string,
	defaultValue: string | (() => Promise<string>),
): Promise<string> => {
	if (Deno.permissions) {
		const { state } = await Deno.permissions.query({
			name: 'env',
			variable: envKey,
		})
		if (state !== 'granted') {
			if (typeof defaultValue === 'function') {
				return await defaultValue()
			} else {
				return defaultValue
			}
		}
	}
	return Deno.env.get(envKey) ||
		(typeof defaultValue === 'function' ? await defaultValue() : defaultValue)
}

export class EnvError extends Error {
}

export const requireEnv = async (envKey: string): Promise<string> => {
	if (Deno.permissions) {
		const { state } = await Deno.permissions.query({
			name: 'env',
			variable: envKey,
		})
		if (state !== 'granted') {
			throw new EnvError(
				`Did not have permission to read environment variable ${envKey}`,
			)
		}
	}
	const result = Deno.env.get(envKey)
	if (result === undefined) {
		throw new EnvError(
			`Environment variable ${envKey} not set`,
		)
	}
	return result
}

export const jsonResponse = (
	object: any,
	additionalResponseOptions?: ResponseInit,
) => {
	const headers = Object.assign({}, additionalResponseOptions?.headers || {}, {
		headers: {
			'content-type': 'application/json; charset=utf8',
		},
	})
	const options = Object.assign({}, additionalResponseOptions, { headers })
	return new Response(JSON.stringify(object), options)
}

export class HttpError extends Error {
	status: number

	constructor(message: string, name: string, status = 500) {
		super(message)
		this.name = name
		this.status = status
	}

	toResponse() {
		const { name, status, message } = this
		return jsonResponse({ id: name, status, message }, { status: status })
	}
}