import Foundation
import UIKit
import SwiftSignalKit
import Postbox
import TelegramCore
import TelegramUIPreferences

public final class InstantPageStoredDetailsState: Codable {
    public let index: Int32
    public let expanded: Bool
    public let details: [InstantPageStoredDetailsState]
    
    public init(index: Int32, expanded: Bool, details: [InstantPageStoredDetailsState]) {
        self.index = index
        self.expanded = expanded
        self.details = details
    }
    
    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: StringCodingKey.self)

        self.index = try container.decode(Int32.self, forKey: "index")
        self.expanded = try container.decode(Bool.self, forKey: "expanded")
        self.details = try container.decode([InstantPageStoredDetailsState].self, forKey: "details")
    }
    
    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: StringCodingKey.self)

        try container.encode(self.index, forKey: "index")
        try container.encode(self.expanded, forKey: "expanded")
        try container.encode(self.details, forKey: "details")
    }
}

public final class InstantPageStoredState: Codable {
    public let contentOffset: Double
    public let details: [InstantPageStoredDetailsState]
    
    public init(contentOffset: Double, details: [InstantPageStoredDetailsState]) {
        self.contentOffset = contentOffset
        self.details = details
    }
    
    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: StringCodingKey.self)

        self.contentOffset = try container.decode(Double.self, forKey: "offset")
        self.details = try container.decode([InstantPageStoredDetailsState].self, forKey: "details")
    }
    
    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: StringCodingKey.self)

        try container.encode(self.contentOffset, forKey: "offset")
        try container.encode(self.details, forKey: "details")
    }
}

public func instantPageStoredState(postbox: Postbox, webPage: TelegramMediaWebpage) -> Signal<InstantPageStoredState?, NoError> {
    return postbox.transaction { transaction -> InstantPageStoredState? in
        let key = ValueBoxKey(length: 8)
        key.setInt64(0, value: webPage.webpageId.id)
        if let entry = transaction.retrieveItemCacheEntry(id: ItemCacheEntryId(collectionId: ApplicationSpecificItemCacheCollectionId.instantPageStoredState, key: key))?.get(InstantPageStoredState.self) {
            return entry
        } else {
            return nil
        }
    }
}

private let collectionSpec = ItemCacheCollectionSpec(lowWaterItemCount: 100, highWaterItemCount: 200)

public func updateInstantPageStoredStateInteractively(postbox: Postbox, webPage: TelegramMediaWebpage, state: InstantPageStoredState?) -> Signal<Void, NoError> {
    return postbox.transaction { transaction -> Void in
        let key = ValueBoxKey(length: 8)
        key.setInt64(0, value: webPage.webpageId.id)
        let id = ItemCacheEntryId(collectionId: ApplicationSpecificItemCacheCollectionId.instantPageStoredState, key: key)
        if let state = state, let entry = CodableEntry(state) {
            transaction.putItemCacheEntry(id: id, entry: entry, collectionSpec: collectionSpec)
        } else {
            transaction.removeItemCacheEntry(id: id)
        }
    }
}