package com.craigvg.lichun_android.utils

import java.text.SimpleDateFormat
import java.util.*
import kotlin.math.abs

object DateFormatters {

    // Python datetime format: "yyyy-MM-dd HH:mm:ss.SSSSSS"
    val pythonDatetime: SimpleDateFormat by lazy {
        SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS", Locale.US)
    }

    val shortDate: SimpleDateFormat by lazy {
        SimpleDateFormat("M/d/yy", Locale.getDefault())
    }

    val shortTime: SimpleDateFormat by lazy {
        SimpleDateFormat("h:mm a", Locale.getDefault())
    }

    val shortDateTime: SimpleDateFormat by lazy {
        SimpleDateFormat("M/d/yy h:mm a", Locale.getDefault())
    }

    val mediumDateTime: SimpleDateFormat by lazy {
        SimpleDateFormat("MMM d, yyyy h:mm a", Locale.getDefault())
    }

    val gameDate: SimpleDateFormat by lazy {
        SimpleDateFormat("MMM dd, yyyy", Locale.US)
    }

    val gameTime: SimpleDateFormat by lazy {
        SimpleDateFormat("h:mm a", Locale.US)
    }

    /**
     * Returns a relative time string like "Just now", "5m ago", "2h ago", "Yesterday"
     */
    fun relativeTime(date: Date): String {
        val now = Date()
        val diffMs = now.time - date.time
        val diffSec = diffMs / 1000
        val diffMin = diffSec / 60
        val diffHours = diffMin / 60
        val diffDays = diffHours / 24

        return when {
            diffSec < 60 -> "Just now"
            diffMin < 60 -> "${diffMin}m ago"
            diffHours < 24 -> "${diffHours}h ago"
            diffDays == 1L -> "Yesterday"
            diffDays < 7 -> "${diffDays}d ago"
            diffDays < 30 -> "${diffDays / 7}w ago"
            else -> shortDate.format(date)
        }
    }

    /**
     * Parse a python datetime string into a Date
     */
    fun parsePythonDatetime(dateString: String): Date? {
        return try {
            pythonDatetime.parse(dateString)
        } catch (_: Exception) {
            null
        }
    }
}