iOS/Sources/Shared/Common/Extensions/KeyedDecodingContainer+JSON.swift

// https://stackoverflow.com/a/46049763/486182
//
//  JSONCodingKeys.swift
//
// original https://gist.github.com/loudmouth/332e8d89d8de2c1eaf81875cfcd22e24
import CoreGraphics
import Foundation

public struct JSONCodingKeys: CodingKey {
    public var stringValue: String

    public init(stringValue: String) {
        self.stringValue = stringValue
    }

    public var intValue: Int?

    public init?(intValue: Int) {
        self.init(stringValue: "\(intValue)")
        self.intValue = intValue
    }
}

public extension KeyedDecodingContainer {
    func decode(_ type: [String: Any].Type, forKey key: K) throws -> [String: Any] {
        let container = try nestedContainer(keyedBy: JSONCodingKeys.self, forKey: key)
        return try container.decode(type)
    }

    func decode(_ type: [Any].Type, forKey key: K) throws -> [Any] {
        var container = try nestedUnkeyedContainer(forKey: key)
        return try container.decode(type)
    }

    func decode(_ type: [String: Any].Type) throws -> [String: Any] {
        var dictionary = [String: Any]()

        for key in allKeys {
            if let boolValue = try? decode(Bool.self, forKey: key) {
                dictionary[key.stringValue] = boolValue
            } else if let stringValue = try? decode(String.self, forKey: key) {
                dictionary[key.stringValue] = stringValue
            } else if let intValue = try? decode(Int.self, forKey: key) {
                dictionary[key.stringValue] = intValue
            } else if let doubleValue = try? decode(Double.self, forKey: key) {
                dictionary[key.stringValue] = doubleValue
            } else if let nestedDictionary = try? decode([String: Any].self, forKey: key) {
                dictionary[key.stringValue] = nestedDictionary
            } else if let nestedArray = try? decode([Any].self, forKey: key) {
                dictionary[key.stringValue] = nestedArray
            }
        }
        return dictionary
    }
}

public extension UnkeyedDecodingContainer {
    mutating func decode(_ type: [Any].Type) throws -> [Any] {
        var array: [Any] = []
        while isAtEnd == false {
            if let value = try? decode(Bool.self) {
                array.append(value)
            } else if let value = try? decode(Double.self) {
                array.append(value)
            } else if let value = try? decode(String.self) {
                array.append(value)
            } else if let nestedDictionary = try? decode([String: Any].self) {
                array.append(nestedDictionary)
            } else if let nestedArray = try? decode([Any].self) {
                array.append(nestedArray)
            }
        }
        return array
    }

    mutating func decode(_ type: [String: Any].Type) throws -> [String: Any] {
        let nestedContainer = try nestedContainer(keyedBy: JSONCodingKeys.self)
        return try nestedContainer.decode(type)
    }
}

public extension KeyedEncodingContainerProtocol where Key == JSONCodingKeys {
    mutating func encode(_ value: [String: Any]) throws {
        for (key, value) in value {
            let key = JSONCodingKeys(stringValue: key)
            switch value {
            case let value as Bool:
                try encode(value, forKey: key)
            case let value as Int:
                try encode(value, forKey: key)
            case let value as String:
                try encode(value, forKey: key)
            case let value as Double:
                try encode(value, forKey: key)
            case let value as CGFloat:
                try encode(value, forKey: key)
            case let value as [String: Any]:
                try encode(value, forKey: key)
            case let value as [Any]:
                try encode(value, forKey: key)
            // swiftformat:disable:next typeSugar
            case Optional<Any>.none:
                try encodeNil(forKey: key)
            default:
                let err = EncodingError.Context(codingPath: codingPath + [key], debugDescription: "Invalid JSON value")
                throw EncodingError.invalidValue(value, err)
            }
        }
    }
}

public extension KeyedEncodingContainerProtocol {
    mutating func encode(_ value: [String: Any]?, forKey key: Key) throws {
        if value != nil {
            var container = nestedContainer(keyedBy: JSONCodingKeys.self, forKey: key)
            try container.encode(value!)
        }
    }

    mutating func encode(_ value: [Any]?, forKey key: Key) throws {
        if value != nil {
            var container = nestedUnkeyedContainer(forKey: key)
            try container.encode(value!)
        }
    }
}

public extension UnkeyedEncodingContainer {
    mutating func encode(_ value: [Any]) throws {
        for (index, value) in value.enumerated() {
            switch value {
            case let value as Bool:
                try encode(value)
            case let value as Int:
                try encode(value)
            case let value as String:
                try encode(value)
            case let value as Double:
                try encode(value)
            case let value as CGFloat:
                try encode(value)
            case let value as [String: Any]:
                try encode(value)
            case let value as [Any]:
                try encode(value)
            // swiftformat:disable:next typeSugar
            case Optional<Any>.none:
                try encodeNil()
            default:
                let keys = JSONCodingKeys(intValue: index).map({ [$0] }) ?? []
                let err = EncodingError.Context(codingPath: codingPath + keys, debugDescription: "Invalid JSON value")
                throw EncodingError.invalidValue(value, err)
            }
        }
    }

    mutating func encode(_ value: [String: Any]) throws {
        var nestedContainer = nestedContainer(keyedBy: JSONCodingKeys.self)
        try nestedContainer.encode(value)
    }
}