// https://developer.apple.com/documentation/foundation
import Foundation
// Foundation is a framework that provides a base layer of functionality
// Literally everything in Swift is built on top of Foundation
// Read the file

/**
    - Parameters:
        - file: The file to be read
    - Returns: The contents of the file as a string
*/
func openFile(_ file: String) -> String {
    var text = ""
    do {
        text = try String(contentsOfFile: file, encoding: .utf8)
    } catch {
        print("Error reading file")
    }
    return text
}

/**
    - Parameters:
        - text: The text to be parsed
    - Returns: An array of dictoinaries representing the data
*/
func parseCSV(_ text: String) -> [[String: String]] {
    var data = [[String: String]]()
    let rows = text.components(separatedBy: "\n")
    let headers = rows[0].components(separatedBy: ",")
    for row in rows[1...] {
        let values = row.components(separatedBy: ",")
        if values.count == headers.count {
            var dict = [String: String]()
            for (index, header) in headers.enumerated() {
                dict[header] = values[index]
            }
            data.append(dict)
        }
    }
    return data
}

// The idea is to pair up the people who have the most in common
// We have people's preferences (P1-P5, all optional), and we want to find the most likely teammates
func mostLikelyTeammates(_ people:[[String: String]], _ groupSize: Int) -> [String: Int] {
    var teammates = [String: Int]()
    for (index, person) in people.enumerated() {
        for (index2, person2) in people.enumerated() {
            if index != index2 {
                var count = 0
                for (key, value) in person {
                    if value == person2[key] {
                        count += 1
                    }
                }
                let key = "\(people[index]["Name"] ?? "John Doe"), \(people[index2]["Name"] ?? "Stan Smith")"
                teammates[key] = count
            }
        }
    }
    return teammates

}

func exportJSON(_ data: [[String: Any]], to file: String) throws {
    let jsonData = try JSONSerialization.data(withJSONObject: data, options: .prettyPrinted)
    let fileURL = URL(fileURLWithPath: file)
    try jsonData.write(to: fileURL)
    print("Successfully written to \(file)")
}


// No duplicates (i.e. John Doe, Stan Smith is the same as Stan Smith, John Doe)
var filteredTeammates = mostLikelyTeammates(parseCSV(openFile("data.csv")), 2).filter { $0.value > 0 }

let sortedTeammates = filteredTeammates.filter { $0.value > 0 }.sorted { $0.value > $1.value }

let jsonExportData = sortedTeammates.map { ["pair": $0.key, "count": $0.value] }

do {
    try exportJSON(jsonExportData, to: "mostLikelyTeammates.json")
} catch {
    print("Error exporting JSON: \(error)")
}