module ParasitemiaUI.State

open System
open System.Collections.Generic
open System.Windows

open Emgu.CV
open Emgu.CV.Structure

open Types

type State (defaultConfig : ParasitemiaCore.Config.Config) =
    let sourceImages = List<SourceImage> ()
    let mutable alteredSinceLastSave = false
    let mutable patientID = ""

    member this.AlteredSinceLastSave = alteredSinceLastSave
    member val CurrentImage : SourceImage option = None with get, set
    member val FilePath : string = "" with get, set

    member this.PatientID
        with get () : string = patientID
        and set id =
            if id <> patientID then
                alteredSinceLastSave <- true
                patientID <- id

    member this.GlobalParasitemia : int * int =
        sourceImages
        |> Seq.fold (
            fun (nbTotal, nbTotalInfected) srcImg ->
                let nb, nbInfected = srcImg.ImageParasitemia
                nbTotal + nb, nbTotalInfected + nbInfected
        ) (0, 0)

    member this.SetAsInfected (rbc : RBC) (infected : bool) =
        if infected <> rbc.infected then
            alteredSinceLastSave <- true
            rbc.infected <- infected
            rbc.setManually <- not rbc.setManually

    /// <summary>
    /// Save the current state. 'FilePath' must have been defined.
    /// </summary>
    /// <exception cref="System.IOException">If the file cannot be saved</exception>
    member this.Save () =
        let data = { PiaZ.DocumentData.patientID = this.PatientID; PiaZ.DocumentData.images = List.ofSeq sourceImages }
        PiaZ.save this.FilePath data
        alteredSinceLastSave <- false

    /// <summary>
    /// Load the current state. 'FilePath' must have been defined.
    /// </summary>
    /// <exception cref="System.IOException">If the file cannot be loaded</exception>
    member this.Load () =
        let data = PiaZ.load this.FilePath defaultConfig
        this.PatientID <- data.patientID
        sourceImages.Clear ()
        sourceImages.InsertRange (0, data.images)
        this.CurrentImage <- if sourceImages.Count > 0 then Some sourceImages.[0] else None
        alteredSinceLastSave <- false

    /// <summary>
    /// </summary>
    /// <exception cref="System.IOException">If the image cannot be read</exception>
    member this.AddSourceImage (filePath : string) (defaultConfig : ParasitemiaCore.Config.Config) : SourceImage =
        let filename = System.IO.FileInfo(filePath).Name
        let srcImg = SourceImage (sourceImages.Count + 1, filename, filename, defaultConfig.Copy (), DateTime (0L), FromFile filePath, [])
        sourceImages.Add srcImg
        if sourceImages.Count = 1 then
            this.CurrentImage <- Some sourceImages.[0]
        alteredSinceLastSave <- true
        srcImg

    member this.RemoveSourceImage (srcImg : SourceImage) =
        let isCurrent =
            match this.CurrentImage with
            | Some srcImg' -> srcImg = srcImg'
            | _ -> false

        if sourceImages.Remove srcImg then
            alteredSinceLastSave <- true
            if isCurrent then
                this.CurrentImage <- if sourceImages.Count > 0 then Some sourceImages.[0] else None
        // Re-numbered the images.
        sourceImages |> Seq.iteri (fun i srcImg -> srcImg.Num <- i + 1)

    member this.SetName (srcImg : SourceImage) (name : string) =
        if name <> srcImg.Name then
            srcImg.Name <- name
            alteredSinceLastSave <- true

    member this.SetResult (imgId : string) (result : ParasitemiaCore.Types.AnalysisResult) =
        let sourceImage = sourceImages.Find (fun srcImg -> srcImg.RomanNum = imgId)

        let w = sourceImage.Img.Width
        let h = sourceImage.Img.Height

        sourceImage.DateLastAnalysis <- DateTime.UtcNow

        // To match with previously manually altered RBC.
        let manuallyAlteredPreviousRBCS = sourceImage.RBCs |> List.filter (fun rbc -> rbc.setManually)
        let tolerance = (float sourceImage.Config.RBCRadius.Pixel) * 0.5 // +/-.
        let getPreviousManuallyAlteredRBC (center : Point) : RBC option =
            manuallyAlteredPreviousRBCS
            |> List.tryFind (
                fun rbc ->
                    rbc.center.X > center.X - tolerance &&
                    rbc.center.X < center.X + tolerance &&
                    rbc.center.Y > center.Y - tolerance &&
                    rbc.center.Y < center.Y + tolerance
            )

        sourceImage.RBCs <-
            result.Cells
            |> List.filter (fun cell -> match cell.cellClass with ParasitemiaCore.Types.HealthyRBC | ParasitemiaCore.Types.InfectedRBC -> true | _ -> false )
            |> List.sortByDescending (fun cell -> cell.nucleusArea, (w - cell.center.X) + (h - cell.center.Y))
            |> List.mapi (
                fun i cell ->
                    let center = Point (float cell.center.X, float cell.center.Y)
                    let infected, setManually =
                        let infected = cell.cellClass = ParasitemiaCore.Types.InfectedRBC
                        match getPreviousManuallyAlteredRBC center with
                        | Some rbc when rbc.infected <> infected -> rbc.infected, true // If it has been previously manually changed and now match the result, the manually flag is removed.
                        | _ -> infected, false
                    {
                        num = i + 1
                        infected = infected
                        setManually = setManually
                        center = center
                        size = Size (float cell.elements.Width, float cell.elements.Height)
                        infectedArea = cell.nucleusArea
                    }
            )

        alteredSinceLastSave <- true

    member this.SourceImages : SourceImage seq =
        sourceImages :> SourceImage seq

    member this.Reset () =
        this.PatientID <- ""
        this.FilePath <- ""
        this.CurrentImage <- None
        sourceImages.Clear ()
        alteredSinceLastSave <- false