import Routing
import Vapor

// MARK: Paths

private let baseFolder = URL(fileURLWithPath: "/caps")

private let logFile = baseFolder.appendingPathComponent("logs/server.log").path

private let publicFolder = baseFolder.appendingPathComponent("Public")

private let imageFolder = publicFolder.appendingPathComponent("images")

private let nameFile = publicFolder.appendingPathComponent("names.txt")

private let tempImageFile = publicFolder.appendingPathComponent("temp.jpg")

// MARK: Variables

private let fm = FileManager.default

private var caps = [String]()

// MARK: SQLite

func loadCapNames() throws {
    let s = try String(contentsOf: nameFile)
    caps = s.trimmingCharacters(in: .whitespacesAndNewlines).components(separatedBy: "\n")
    log("\(caps.count) caps loaded")
}

// MARK: Helper

private func folder(of cap: Int) -> URL {
    imageFolder.appendingPathComponent(String(format: "%04d", cap))
}

private func file(of cap: Int, version: Int) -> URL {
    folder(of: cap).appendingPathComponent(String(format: "%04d-%02d.jpg", cap, version))
}

private func countImages(in folder: URL) throws -> Int {
    try fm.contentsOfDirectory(at: folder, includingPropertiesForKeys: nil).filter({ $0.pathExtension == "jpg" }).count
}

private func count(of cap: Int) throws -> Int {
    let f = folder(of: cap)
    guard fm.fileExists(atPath: f.path) else {
        return 0
    }
    return try countImages(in: f)
}

// MARK: Routes

/// Register your application's routes here.
///
/// [Learn More →](https://docs.vapor.codes/3.0/getting-started/structure/#routesswift)
public func routes(_ router: Router) throws {
    
    try Log.set(logFile: logFile)
    try loadCapNames()
    
    // Get the name of a cap
    router.getCatching("name", Int.parameter) { request -> Data in
        let cap = try request.parameters.next(Int.self)
        guard cap < caps.count else {
            throw CapError.unknownId
        }
        return caps[cap].data(using: .utf8)!
    }
    
    // Set the name of a cap
    router.postCatching("name", Int.parameter) { request in
        let cap = try request.parameters.next(Int.self)
        guard let data = request.http.body.data, let name = String(data: data, encoding: .utf8) else {
            throw CapError.invalidBody
        }
        guard cap <= caps.count else {
            throw CapError.unknownId
        }
        
        if cap == caps.count {
            caps.append(name)
            // Create image folder
            let url = folder(of: cap)
            if !fm.fileExists(atPath: url.path) {
                try fm.createDirectory(at: url, withIntermediateDirectories: false)
            }
        } else {
            caps[cap] = name
        }
        try caps.joined(separator: "\n").data(using: .utf8)!.write(to: nameFile)
    }
    
    // Upload an image
    router.postCatching("images", Int.parameter) { request -> Data in
        let cap = try request.parameters.next(Int.self)
        guard let data = request.http.body.data else {
            throw CapError.invalidBody
        }
        let c = try count(of: cap)
        let f = file(of: cap, version: c)
        guard !fm.fileExists(atPath: f.path) else {
            throw CapError.dataInconsistency
        }
        try data.write(to: f)
        return "\(c)".data(using: .utf8)!
    }
    
    // Get count of a cap
    router.getCatching("count", Int.parameter) { request -> Data in
        let cap = try request.parameters.next(Int.self)
        let c = try count(of: cap)
        return "\(c)".data(using: .utf8)!
    }
    
    // Get the count of all caps
    router.getCatching("counts") { request -> Data in
        try (1...caps.count).map { UInt8(try count(of: $0)) }.convertToData()
    }
    
    // Set a different version as the main image
    router.getCatching("switch", Int.parameter, Int.parameter) { request in
        let cap = try request.parameters.next(Int.self)
        let version = try request.parameters.next(Int.self)
        guard version > 0 else {
            return
        }
        let file1 = file(of: cap, version: 0)
        guard fm.fileExists(atPath: file1.path) else {
            throw CapError.invalidFile
        }
        let file2 = file(of: cap, version: version)
        guard fm.fileExists(atPath: file2.path) else {
            throw CapError.invalidFile
        }
        try fm.moveItem(at: file1, to: tempImageFile)
        try fm.moveItem(at: file2, to: file1)
        try fm.moveItem(at: tempImageFile, to: file2)
    }
}