// 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
        fileVersion : int
    }

// Information associated to each images.
type JSONSourceImage =
    {
        num : int
        name : string

        RBCRadius : float32 // The RBC Radius found by granulometry.
        parameters : ParasitemiaCore.Config.Parameters
        dateLastAnalysis : DateTime
        rbcs : RBC List

        healthyRBCBrightness : float32 // 0 to 1.
        infectedRBCBrightness : float32 // 0 to 1.
    }

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

let mainEntryName = "info.json"
let imageExtension = ".tiff"
let currentFileVersion = 2

/// <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 ({ patientID = data.patientID; fileVersion = currentFileVersion }))

    // 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
                    name = srcImg.name
                    RBCRadius = srcImg.config.RBCRadius.Pixel
                    parameters = srcImg.config.Parameters
                    dateLastAnalysis = srcImg.dateLastAnalysis
                    rbcs = srcImg.rbcs
                    healthyRBCBrightness = srcImg.healthyRBCBrightness
                    infectedRBCBrightness = srcImg.infectedRBCBrightness
                }
            )
        )

let updateDocumentData (fromVersion : int) (toVersion : int) (data : DocumentData) : DocumentData =
    for v in fromVersion + 1 .. toVersion do
        match v with
        | 1 -> // Version 0 -> 1 : set initial brightness for rbc.
            data.images |> List.iter (fun i -> i.healthyRBCBrightness <- 1.f; i.infectedRBCBrightness <- 1.f)
        | _ -> ()
    data

/// <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) (defaultConfig : ParasitemiaCore.Config.Config) : 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 ())

    updateDocumentData info.fileVersion currentFileVersion
        {
            patientID = info.patientID
            images =
                [
                    let mutable imgNum = 0
                    for imgEntry in file.Entries do
                        if imgEntry.Name.EndsWith (imageExtension) then
                            use bitmap = new System.Drawing.Bitmap (imgEntry.Open (), false)
                            let img = new Image<Bgr, byte> (bitmap)
                            imgNum <- imgNum + 1
                            let imgJSONEntry = file.GetEntry (imgEntry.Name + ".json")
                            use imgJSONFileReader = new StreamReader (imgJSONEntry.Open ())
                            let imgInfo = JsonConvert.DeserializeObject<JSONSourceImage> (imgJSONFileReader.ReadToEnd ())

                            let config = defaultConfig.Copy ()
                            config.Parameters <-
                                {
                                    ParasitemiaCore.Config.defaultParameters with
                                        resolution = imgInfo.parameters.resolution
                                }

                            config.SetRBCRadius imgInfo.RBCRadius
                            yield
                                {
                                    num = imgNum
                                    name = imgInfo.name
                                    config = config
                                    dateLastAnalysis = imgInfo.dateLastAnalysis
                                    img = img
                                    rbcs = imgInfo.rbcs
                                    healthyRBCBrightness = imgInfo.healthyRBCBrightness
                                    infectedRBCBrightness = imgInfo.infectedRBCBrightness
                                }
                ]
        }