// ParasitemIA Zipped document format.
module ParasitemiaUI.PiaZ

open System
open System.Windows
open System.IO
open System.IO.Compression

open Emgu.CV
open Emgu.CV.Structure

open Newtonsoft.Json
open Newtonsoft.Json.Converters

open Types

let extension = ".piaz"
let filter = "PIA|*.piaz"

// Information associated to a document.
type JSONInformation = {
    patientID: string
}

// Information associated to each images.
type JSONSourceImage = {
    num: int
    RBCRadius: float32 // The RBC Radius found by granulometry.
    parameters: ParasitemiaCore.Config.Parameters
    dateLastAnalysis: DateTime
    rbcs: RBC List
}

type DocumentData = {
    patientID: string
    images: SourceImage list
}

let mainEntryName = "info.json"
let imageExtension = ".tiff"

/// <summary>
/// Save a document in a give file path. The file may already exist.
/// </summary>
/// <param name="filePath"></param>
/// <param name="data"></param>
/// <exception cref="System.IOException">If the file cannot be written</exception>
let save (filePath: string) (data: DocumentData) =
    use file = ZipFile.Open(filePath, ZipArchiveMode.Update)

    for e in List.ofSeq file.Entries do // 'ofSeq' to not iterate a collection currently modified.
        e.Delete()

    // Main JSON file.
    let mainEntry = file.CreateEntry(mainEntryName, CompressionLevel.Fastest)
    use mainEntryWriter = new StreamWriter(mainEntry.Open())
    mainEntryWriter.Write(JsonConvert.SerializeObject({ JSONInformation.patientID = data.patientID }))

    // Write each images and the associated information.
    for srcImg in data.images do
        let imgFilename = (string srcImg.num) + imageExtension
        let imgEntry = file.CreateEntry(imgFilename, CompressionLevel.NoCompression) // FIXME: It seems a compression is applied to this file despite of the 'NoCompression' flag.
        srcImg.img.ToBitmap().Save(imgEntry.Open(), System.Drawing.Imaging.ImageFormat.Tiff)

        let imgJSONEntry = file.CreateEntry(imgFilename + ".json", CompressionLevel.Fastest)
        use imgJSONFileWriter = new StreamWriter(imgJSONEntry.Open())
        imgJSONFileWriter.Write(JsonConvert.SerializeObject({ num = srcImg.num; RBCRadius = srcImg.config.RBCRadius.Pixel; parameters = srcImg.config.Parameters; dateLastAnalysis = srcImg.dateLastAnalysis; rbcs = srcImg.rbcs }))

/// <summary>
/// Load document from a give file path.
/// </summary>
/// <param name="filePath"></param>
/// <exception cref="System.IOException">If the file cannot be read</exception>
let load (filePath: string) : DocumentData =
    use file = ZipFile.Open(filePath, ZipArchiveMode.Read)

    let mainEntry = file.GetEntry(mainEntryName)
    use mainEntryReader = new StreamReader(mainEntry.Open())
    let info = JsonConvert.DeserializeObject<JSONInformation>(mainEntryReader.ReadToEnd())

    { patientID = info.patientID
      images = [ let mutable imgNum = 0
                 for imgEntry in file.Entries do
                    if imgEntry.Name.EndsWith(imageExtension)
                    then
                        let img = new Image<Bgr, byte>(new System.Drawing.Bitmap(imgEntry.Open(), false)) // FIXME: Should we dispose the bitmap?
                        imgNum <- imgNum + 1
                        let imgEntry = file.GetEntry(imgEntry.Name + ".json")
                        use imgEntryFileReader = new StreamReader(imgEntry.Open())
                        let imgInfo = JsonConvert.DeserializeObject<JSONSourceImage>(imgEntryFileReader.ReadToEnd())
                        let config = ParasitemiaCore.Config.Config(imgInfo.parameters)
                        config.SetRBCRadius imgInfo.RBCRadius
                        yield { num = imgNum
                                config = config
                                dateLastAnalysis = imgInfo.dateLastAnalysis
                                img = img
                                rbcs = imgInfo.rbcs } ] }