//
//  KMMergeFileModel.swift
//  PDF Reader Pro
//
//  Created by tangchao on 2022/11/24.
//

import Cocoa
import PDFKit

enum KMMergeFilePageRange: String {
    case all = "All Page"
    case oddPages = "Odd pages Only"
    case evenPages = "Even pages Only"
    case custom = ""
}

class KMMergeFileModel: NSObject {
    var documentURL: URL!
    var document: CPDFDocument!
    var open : Bool = false
    var page: CPDFPage!
    
    var password: String!
    
    var myDocument: CPDFDocument!
    
    var selected: Bool = false
    var pageRange: KMMergeFilePageRange = .all
    var pageRangeString: String = ""
    
    var pages: [KMMergePageModel] = []
    
    func canExpand() -> Bool {
        return document.pageCount > 1
    }
    
    func updateChildPageRange(pageRange: KMMergeFilePageRange) {
        if pageRange == .all {
            for pageModel in pages {
                pageModel.selected = true
            }
        } else if pageRange == .oddPages {
            var i = 0
            for pageModel in pages {
                if i % 2 == 0 {
                    pageModel.selected = true
                } else {
                    pageModel.selected = false
                }
                i += 1
            }
        } else if pageRange == .evenPages {
            var i = 0
            for pageModel in pages {
                if i % 2 == 0 {
                    pageModel.selected = false
                } else {
                    pageModel.selected = true
                }
                i += 1
            }
        } else if pageRange == .custom {
            
        }
    }
    
    func updatePagePange() {
        var allPage = true
        var oddPage = true
        var evenPage = true
        var selectedPages: [Int] = []
        
        for model in pages {
            if model.selected {
                selectedPages.append(model.pageID+1)
                
                if model.pageID % 2 == 1 { /// 偶数
                    oddPage = false
                } else { /// 奇数
                    evenPage = false
                }
            } else {
                allPage = false
                
                if model.pageID % 2 == 0 { /// 奇数
                    oddPage = false
                } else { /// 偶数
                    evenPage = false
                }
            }
        }
        
        if allPage {
            pageRange = .all
        } else if oddPage {
            pageRange = .oddPages
        } else if evenPage {
            pageRange = .evenPages
        } else {
            pageRange = .custom
            var string: String = ""
            var index = 0
            var prePage = 0
            var count = 0
            var cubeStart = NSNotFound
            var cubeEnd = NSNotFound
            for i in selectedPages {
                if selectedPages.count == 1 {
                    string.append(String(i))
                } else if selectedPages.count == 2 {
                    string.append(String(i))
                    if index != selectedPages.count-1 {
                        string.append(",")
                    }
                } else {
                    if index == 0 {
                        string.append(String(i))
                    } else {
                        if i - prePage == 1 {
                            if count == 0 {
                                cubeStart = prePage
                            }
                            
                            count += 1
                        } else {
                            count = 0
                        }
                        
                        if count == 0 || index == selectedPages.count-1 { /// 块结束
                            if cubeStart != NSNotFound && cubeEnd != NSNotFound { /// 有效块
                                if cubeStart == selectedPages.first {
                                    string.removeFirst()
                                } else {
                                    string.append(",")
                                }
                                
                                
                                if index == selectedPages.count-1 {
                                    if count == 0 {
                                        string.append(String(cubeStart))
                                        string.append("-")
                                        string.append(String(cubeEnd))
                                        
                                        string.append(",")
                                        string.append(String(i))
                                    } else {
                                        string.append(String(cubeStart))
                                        string.append("-")
                                        string.append(String(i))
                                    }
                                } else {
                                    string.append(String(cubeStart))
                                    string.append("-")
                                    string.append(String(cubeEnd))
                                }
                            } else {
                                if prePage == selectedPages.first {
//                                    string.append(",")
                                } else {
                                    string.append(",")
                                    string.append(String(prePage))
                                }
                                
                                cubeStart = NSNotFound
                                cubeEnd = NSNotFound
                            }
                        }
//                        else if count == 1 {
//                            if index == selectedPages.count-1 {
//                                if prePage == selectedPages.first {
////                                    string.append(",")
//                                } else {
//                                    string.append(",")
//                                    string.append(String(prePage))
//                                }
//                            }
//                        }
                        else if count >= 2 { /// 可成块
                            cubeEnd = i
                        }
                    }
                }
                
                prePage = i
                index += 1
            }
            pageRangeString = string
        }
    }
}