/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- vim: ft=cpp et ts=4 sw=4:
 *
 * Copyright (c) 2023 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 *
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 *
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 *
 * @APPLE_LICENSE_HEADER_END@
 */

// TODO: Do some nice ASCII artwork for the schema, for now the validation code will serve as documentation

protocol AtlasSchemaValidator {
    // validate the schema of a bplist object corresponding to a give class, recusrively
    // All validation failures throw, so we can (eventually) encode richer failure information
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError)
}


extension Snapshot.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        try bplist.validate(key:"proc",     as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"plat",     as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"time",     as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"stat",     as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"init",     as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"flags",    as:Int64.self,  throwAs:AtlasError.self,                optional:true)
        try bplist.validate(key:"suid",     as:Data.self,   throwAs:AtlasError.self,    count:16,   optional:true)
        try bplist.validateArray(key:"imgs", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try Image.Impl.validate(bplist:bplist)
        }
        try bplist.validateArray(key:"aots", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self, optional:true) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try AOTImage.Impl.validate(bplist:bplist)
        }
        if let sharedCacheProcessRecord = bplist["envp", as:BPList.UnsafeRawDictionary.self] {
            try Environment.Impl.validate(bplist:sharedCacheProcessRecord)
        }
        if let sharedCacheProcessRecord = bplist["dsc1", as:BPList.UnsafeRawDictionary.self] {
            try SharedCache.ProcessRecord.validate(bplist:sharedCacheProcessRecord)
        }
    }
}

extension Environment.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        try bplist.validate(key:"root",    as:String.self,  throwAs:AtlasError.self,                optional:true)
    }
}

extension SharedCache.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        try bplist.validate(key:"uuid", as:Data.self,   throwAs:AtlasError.self,    count:16)
        try bplist.validate(key:"padr", as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"psze", as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"size", as:Int64.self,  throwAs:AtlasError.self)
        try bplist.validate(key:"snme", as:String.self, throwAs:AtlasError.self,                optional:true)
        try bplist.validate(key:"suid", as:Data.self,   throwAs:AtlasError.self,    count:16,   optional:true)
        try bplist.validateArray(key:"imgs", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try Image.Impl.validate(bplist:bplist)
        }
        try bplist.validateArray(key:"aots", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self, optional:true) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try AOTImage.Impl.validate(bplist:bplist)
        }
    }
}

extension SharedCache.ProcessRecord: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        do throws(BPListError) {
            try bplist.validate(key:"uuid", as:Data.self,   count:16)
            try bplist.validate(key:"bitm", as:Data.self)
            try bplist.validate(key:"addr", as:Int64.self)
            try bplist.validate(key:"file", as:String.self)
            try bplist.validate(key:"aadr", as:Int64.self,              optional:true)
            try bplist.validate(key:"auid", as:Data.self,   count:16,   optional:true)
        } catch {
            throw .bplistError(error)
        }
    }
}

extension SubCache.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        try bplist.validate(key:"uuid", as:Data.self,   throwAs:AtlasError.self,    count:16)
        try bplist.validate(key:"name", as:String.self, throwAs:AtlasError.self)
        try bplist.validate(key:"size", as:Data.self,   throwAs:AtlasError.self)
        try bplist.validate(key:"fsze", as:Data.self,   throwAs:AtlasError.self)
        try bplist.validate(key:"voff", as:Data.self,   throwAs:AtlasError.self)
        try bplist.validate(key:"padr", as:Data.self,   throwAs:AtlasError.self)
        try bplist.validate(key:"suid", as:Data.self,   throwAs:AtlasError.self,    count:16,   optional:true)
        try bplist.validateArray(key:"maps", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try SubCache.Mapping.validate(bplist:bplist)
        }
    }
}

extension SubCache.Mapping: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        do {
            try bplist.validate(key:"padr", as:Int64.self)
            try bplist.validate(key:"size", as:Int64.self)
            try bplist.validate(key:"foff", as:Int64.self)
            try bplist.validate(key:"prot", as:Int64.self)
        } catch {
            throw .bplistError(error)
        }
    }
}

extension Image.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        var validAddress = true
        do throws(BPListError) {
            let hasPreferredAddress =   try bplist.validate(key:"padr", as:Int64.self,              optional:true)
            let hasAddress          =   try bplist.validate(key:"addr", as:Int64.self,              optional:true)
                                        try bplist.validate(key:"uuid", as:Data.self,   count:16,   optional:true)
                                        try bplist.validate(key:"name", as:String.self,             optional:true)
                                        try bplist.validate(key:"file", as:String.self,             optional:true)
            if hasPreferredAddress == nil, hasAddress == nil {
                // All shared cache images have a preferred load address, and all non-shared cache images have a load address (as well
                // as a preferred load address if they are not built to load at address zero). If neither are present the image record
                // is malformed
                validAddress = false
            }
        } catch {
            throw .bplistError(error)
        }
        guard validAddress == true else {
            throw .schemaValidationError
        }
        try bplist.validateArray(key:"segs", of:BPList.UnsafeRawDictionary.self, throwAs:AtlasError.self) { (bplist:BPList.UnsafeRawDictionary) throws(AtlasError) -> Void in
            return try Segment.Impl.validate(bplist:bplist)
        }
    }
}

extension Segment.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        do throws(BPListError) {
            try bplist.validate(key:"uuid", as:Data.self, count:16, optional:true)
            try bplist.validate(key:"name", as:String.self)
            try bplist.validate(key:"size", as:Int64.self)
            try bplist.validate(key:"fsze", as:Int64.self)
            try bplist.validate(key:"padr", as:Int64.self)
            try bplist.validate(key:"perm", as:Int64.self)
        } catch {
            throw .bplistError(error)
        }
    }
}

extension  AOTImage.Impl: AtlasSchemaValidator {
    static func validate(bplist: BPList.UnsafeRawDictionary) throws(AtlasError) {
        do throws(BPListError) {
            try bplist.validate(key:"xadr", as:Int64.self)
            try bplist.validate(key:"aadr", as:Int64.self)
            try bplist.validate(key:"asze", as:Int64.self)
            try bplist.validate(key:"ikey", as:Data.self)
        } catch {
            throw .bplistError(error)
        }
    }
}