package com.suno.android.common_data.billing

import androidx.annotation.VisibleForTesting
import com.suno.android.common_core_utils.environment.UserPrefsDataStoreManager
import com.suno.android.common_networking.remote.session.MaxLengths
import com.suno.android.common_networking.remote.session.Model
import com.suno.android.common_networking.remote.session.ModelFeatures
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.combine
import kotlinx.coroutines.flow.map
import javax.inject.Inject

interface SelectedModelProvider {
    fun getSelectedModelFlow(): Flow<Model>

    companion object {
        const val FALLBACK_MODEL_KEY: String = "chirp-auk-turbo"
        const val FALLBACK_MODEL_NAME: String = "v4.5-all"

        @VisibleForTesting
        val FALLBACK_DEFAULT_MODEL: Model = Model(
            canUse = true,
            capabilities = emptyList(),
            features = listOf(ModelFeatures.CreateControlSliders.value, ModelFeatures.TagUpsample.value),
            description = "Best free model",
            externalKey = FALLBACK_MODEL_KEY,
            id = "0f2d749c-2ecd-4c5c-9389-13468ce46e59",
            majorVersion = 5,
            maxLengths = MaxLengths(
                gptDescriptionPrompt = 500,
                negativeTags = 1000,
                prompt = 5000,
                tags = 1000,
                title = 100,
            ),
            name = FALLBACK_MODEL_NAME,
            isDefaultModel = true,
            badges = emptyList(),
        )
    }
}

class SelectedModelProviderImpl @Inject constructor(
    private val billingRepo: SunoBillingRepo,
    private val userPrefsDataStoreManager: UserPrefsDataStoreManager,
) : SelectedModelProvider {
    override fun getSelectedModelFlow(): Flow<Model> =
        combine(
            billingRepo.billingStateFlow(),
            userPrefsDataStoreManager.getSelectedModel(),
            ::Pair,
        ).map { (billingInfo, selectedModelName) ->
            val availableModels = billingInfo?.models ?: emptyList()
            availableModels.find { it.name == selectedModelName && !it.externalKey.isNullOrBlank() }
                ?: SelectedModelProvider.FALLBACK_DEFAULT_MODEL
        }
}