import Foundation enum AmpUsageParser {    static func parse(html: String, now: Date = Date()) throws -> AmpUsageSnapshot {        guard let usage = self.parseFreeTierUsage(html) else {            if self.looksSignedOut(html) {                throw AmpUsageError.notLoggedIn            }            throw AmpUsageError.parseFailed("Missing Amp Free usage data.")        }         return AmpUsageSnapshot(            freeQuota: usage.quota,            freeUsed: usage.used,            hourlyReplenishment: usage.hourlyReplenishment,            windowHours: usage.windowHours,            updatedAt: now)    }     static func parse(displayText: String, now: Date = Date()) throws -> AmpUsageSnapshot {        let text = TextParsing.stripANSICodes(displayText)        let identityPattern = #"(?im)^\s*Signed in as\s+([^\s(]+)(?:\s+\(([^\r\n)]+)\))?\s*$"#        let identity = self.captures(in: text, pattern: identityPattern)        if identity == nil, self.looksSignedOut(text) {            throw AmpUsageError.notLoggedIn        }         let amountPattern = #"([0-9][0-9,]*(?:\.[0-9]+)?)"#        let freePattern = #"(?im)^\s*Amp Free:\s*\$?"# + amountPattern +            #"\s*/\s*\$?"# + amountPattern +            #"\s+remaining(?:\s*\(replenishes\s*\+\$?"# + amountPattern + #"\s*/\s*hour\))?"#        let creditsPattern = #"(?im)^\s*Individual credits:\s*\$?"# + amountPattern + #"\s+remaining"#        let individualCredits = self.captures(in: text, pattern: creditsPattern)?.first            .flatMap(self.number(from:))        let workspacePattern = #"(?im)^\s*Workspace\s+(.+?):\s*\$?"# + amountPattern + #"\s+remaining"#        let workspaceBalances: [AmpWorkspaceBalance] = self.allCaptures(            in: text,            pattern: workspacePattern).compactMap { captures -> AmpWorkspaceBalance? in            guard captures.count == 2,                  let name = self.nonEmpty(captures[0]),                  let remaining = self.number(from: captures[1])            else { return nil }            return AmpWorkspaceBalance(name: name, remaining: remaining)        }        let freeUsage: FreeTierUsage? = {            guard let free = self.captures(in: text, pattern: freePattern),                  let remaining = self.number(from: free[0]),                  let quota = self.number(from: free[1])            else { return nil }            let hourlyReplenishment = self.number(from: free[2]) ?? 0            let windowHours = hourlyReplenishment > 0                ? max(1, (quota / hourlyReplenishment).rounded())                : nil            return FreeTierUsage(                quota: quota,                used: max(0, quota - remaining),                hourlyReplenishment: hourlyReplenishment,                windowHours: windowHours)        }()        guard freeUsage != nil || individualCredits != nil || !workspaceBalances.isEmpty else {            throw AmpUsageError.parseFailed("Missing Amp usage data.")        }         return AmpUsageSnapshot(            freeQuota: freeUsage?.quota,            freeUsed: freeUsage?.used,            hourlyReplenishment: freeUsage?.hourlyReplenishment,            windowHours: freeUsage?.windowHours,            individualCredits: individualCredits,            workspaceBalances: workspaceBalances,            accountEmail: self.nonEmpty(identity?[0]),            accountOrganization: self.nonEmpty(identity?[1]),            updatedAt: now)    }     private struct FreeTierUsage {        let quota: Double        let used: Double        let hourlyReplenishment: Double        let windowHours: Double?    }     private static func parseFreeTierUsage(_ html: String) -> FreeTierUsage? {        let tokens = ["freeTierUsage", "getFreeTierUsage"]        for token in tokens {            if let object = self.extractObject(named: token, in: html),               let usage = self.parseFreeTierUsageObject(object)            {                return usage            }        }        return nil    }     private static func parseFreeTierUsageObject(_ object: String) -> FreeTierUsage? {        guard let quota = self.number(for: "quota", in: object),              let used = self.number(for: "used", in: object),              let hourly = self.number(for: "hourlyReplenishment", in: object)        else { return nil }         let windowHours = self.number(for: "windowHours", in: object)        return FreeTierUsage(            quota: quota,            used: used,            hourlyReplenishment: hourly,            windowHours: windowHours)    }     private static func extractObject(named token: String, in text: String) -> String? {        guard let tokenRange = text.range(of: token) else { return nil }        guard let braceIndex = text[tokenRange.upperBound...].firstIndex(of: "{") else { return nil }         var depth = 0        var inString = false        var isEscaped = false        var index = braceIndex         while index < text.endIndex {            let char = text[index]            if inString {                if isEscaped {                    isEscaped = false                } else if char == "\\" {                    isEscaped = true                } else if char == "\"" {                    inString = false                }            } else {                if char == "\"" {                    inString = true                } else if char == "{" {                    depth += 1                } else if char == "}" {                    depth -= 1                    if depth == 0 {                        return String(text[braceIndex...index])                    }                }            }            index = text.index(after: index)        }         return nil    }     private static func number(for key: String, in text: String) -> Double? {        let pattern = "\\b\(NSRegularExpression.escapedPattern(for: key))\\b\\s*:\\s*([0-9]+(?:\\.[0-9]+)?)"        guard let regex = try? NSRegularExpression(pattern: pattern) else { return nil }        let range = NSRange(text.startIndex..<text.endIndex, in: text)        guard let match = regex.firstMatch(in: text, options: [], range: range),              match.numberOfRanges > 1,              let valueRange = Range(match.range(at: 1), in: text)        else { return nil }        return Double(text[valueRange])    }     private static func captures(in text: String, pattern: String) -> [String]? {        guard let regex = try? NSRegularExpression(pattern: pattern) else { return nil }        let range = NSRange(text.startIndex..<text.endIndex, in: text)        guard let match = regex.firstMatch(in: text, options: [], range: range) else { return nil }         return self.captures(in: text, match: match)    }     private static func allCaptures(in text: String, pattern: String) -> [[String]] {        guard let regex = try? NSRegularExpression(pattern: pattern) else { return [] }        let range = NSRange(text.startIndex..<text.endIndex, in: text)        return regex.matches(in: text, options: [], range: range).map { match in            self.captures(in: text, match: match)        }    }     private static func captures(in text: String, match: NSTextCheckingResult) -> [String] {        (1..<match.numberOfRanges).map { index in            let captureRange = match.range(at: index)            guard captureRange.location != NSNotFound,                  let range = Range(captureRange, in: text)            else { return "" }            return String(text[range]).trimmingCharacters(in: .whitespacesAndNewlines)        }    }     private static func number(from text: String) -> Double? {        Double(text.replacingOccurrences(of: ",", with: ""))    }     private static func nonEmpty(_ text: String?) -> String? {        guard let text, !text.isEmpty else { return nil }        return text    }     private static func looksSignedOut(_ html: String) -> Bool {        let lower = html.lowercased()        if lower.contains("sign in") || lower.contains("log in") || lower.contains("login") {            return true        }        if lower.contains("/login") || lower.contains("ampcode.com/login") {            return true        }        return false    }}