/*
 * This file is part of GNU Taler
 * (C) 2020 Taler Systems S.A.
 *
 * GNU Taler is free software; you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 3, or (at your option) any later version.
 *
 * GNU Taler is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * GNU Taler; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

package net.taler.merchantlib

import io.ktor.client.HttpClient
import io.ktor.client.call.body
import io.ktor.client.engine.okhttp.OkHttp
import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
import io.ktor.client.request.HttpRequestBuilder
import io.ktor.client.request.delete
import io.ktor.client.request.get
import io.ktor.client.request.header
import io.ktor.client.request.post
import io.ktor.client.request.setBody
import io.ktor.http.ContentType.Application.Json
import io.ktor.http.HttpHeaders.Authorization
import io.ktor.http.contentType
import io.ktor.serialization.kotlinx.json.json
import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.withContext
import kotlinx.serialization.json.Json
import net.taler.merchantlib.Response.Companion.response

class MerchantApi(
    private val httpClient: HttpClient = getDefaultHttpClient(),
    private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO,
) {

    suspend fun getConfig(baseUrl: String): Response<ConfigResponse> = withContext(ioDispatcher) {
        response {
            httpClient.get("$baseUrl/config").body()
        }
    }

    suspend fun postOrder(
        merchantConfig: MerchantConfig,
        orderRequest: PostOrderRequest,
    ): Response<PostOrderResponse> = withContext(ioDispatcher) {
        response {
            httpClient.post(merchantConfig.urlFor("private/orders")) {
                auth(merchantConfig)
                contentType(Json)
                setBody(orderRequest)
            }.body()
        }
    }

    suspend fun checkOrder(
        merchantConfig: MerchantConfig,
        orderId: String,
    ): Response<CheckPaymentResponse> = withContext(ioDispatcher) {
        response {
            httpClient.get(merchantConfig.urlFor("private/orders/$orderId")) {
                auth(merchantConfig)
            }.body()
        }
    }

    suspend fun deleteOrder(
        merchantConfig: MerchantConfig,
        orderId: String,
    ): Response<Unit> = withContext(ioDispatcher) {
        response {
            httpClient.delete(merchantConfig.urlFor("private/orders/$orderId")) {
                auth(merchantConfig)
            }.body()
        }
    }

    suspend fun getOrderHistory(merchantConfig: MerchantConfig): Response<OrderHistory> =
        withContext(ioDispatcher) {
            response {
                httpClient.get(merchantConfig.urlFor("private/orders")) {
                    auth(merchantConfig)
                }.body()
            }
        }

    suspend fun giveRefund(
        merchantConfig: MerchantConfig,
        orderId: String,
        request: RefundRequest,
    ): Response<RefundResponse> = withContext(ioDispatcher) {
        response {
            httpClient.post(merchantConfig.urlFor("private/orders/$orderId/refund")) {
                auth(merchantConfig)
                contentType(Json)
                setBody(request)
            }.body()
        }
    }

    private fun HttpRequestBuilder.auth(merchantConfig: MerchantConfig) {
        header(Authorization, "Bearer ${merchantConfig.apiKey}")
    }
}

fun getDefaultHttpClient(): HttpClient = HttpClient(OkHttp) {
    expectSuccess = true
    engine {
        config {
            retryOnConnectionFailure(true)
        }
    }
    install(ContentNegotiation) {
        json(Json {
            encodeDefaults = false
            ignoreUnknownKeys = true
        })
    }
}