import Foundation

public struct RDEPUBTextAnchor: Codable, Equatable {

    public let fileIndex: Int

    public let row: Int

    public let column: Int

    public let chapterOffset: Int

    public let fragmentID: String?

    public var spineIndex: Int { fileIndex }

    public init(
        fileIndex: Int,
        row: Int,
        column: Int,
        chapterOffset: Int,
        fragmentID: String? = nil
    ) {
        self.fileIndex = fileIndex
        self.row = row
        self.column = column
        self.chapterOffset = chapterOffset
        self.fragmentID = fragmentID
    }

    enum CodingKeys: String, CodingKey {
        case fileIndex
        case spineIndex
        case row
        case column
        case chapterOffset
        case fragmentID
    }

    public init(from decoder: Decoder) throws {
        let container = try decoder.container(keyedBy: CodingKeys.self)
        let decodedFileIndex = try container.decodeIfPresent(Int.self, forKey: .fileIndex)
            ?? container.decode(Int.self, forKey: .spineIndex)
        self.fileIndex = decodedFileIndex
        self.row = try container.decodeIfPresent(Int.self, forKey: .row) ?? 0
        self.column = try container.decodeIfPresent(Int.self, forKey: .column) ?? 0
        self.chapterOffset = try container.decode(Int.self, forKey: .chapterOffset)
        self.fragmentID = try container.decodeIfPresent(String.self, forKey: .fragmentID)
    }

    public func encode(to encoder: Encoder) throws {
        var container = encoder.container(keyedBy: CodingKeys.self)
        try container.encode(fileIndex, forKey: .fileIndex)
        try container.encode(row, forKey: .row)
        try container.encode(column, forKey: .column)
        try container.encode(chapterOffset, forKey: .chapterOffset)
        try container.encodeIfPresent(fragmentID, forKey: .fragmentID)
    }
}

public struct RDEPUBTextRangeAnchor: Codable, Equatable {

    public let start: RDEPUBTextAnchor

    public let end: RDEPUBTextAnchor

    public init(start: RDEPUBTextAnchor, end: RDEPUBTextAnchor) {
        self.start = start
        self.end = end
    }

    public var nsRange: NSRange {
        NSRange(location: start.chapterOffset, length: max(end.chapterOffset - start.chapterOffset, 0))
    }
}