import Foundation

public enum KimiSettingsReader {
    public static let apiKeyEnvironmentKeys = ["KIMI_CODE_API_KEY"]
    public static let codeAPIBaseURLEnvironmentKey = "KIMI_CODE_BASE_URL"
    public static let defaultCodeAPIBaseURL = URL(string: "https://api.kimi.com")!

    public static func authToken(environment: [String: String] = ProcessInfo.processInfo.environment) -> String? {
        let raw = environment["KIMI_AUTH_TOKEN"] ?? environment["kimi_auth_token"]
        return self.cleaned(raw)
    }

    public static func apiKey(environment: [String: String] = ProcessInfo.processInfo.environment) -> String? {
        for key in self.apiKeyEnvironmentKeys {
            if let value = self.cleaned(environment[key]) {
                return value
            }
        }
        return nil
    }

    public static func codeAPIBaseURL(
        environment: [String: String] = ProcessInfo.processInfo.environment) throws -> URL
    {
        guard let raw = self.cleaned(environment[self.codeAPIBaseURLEnvironmentKey]) else {
            return self.defaultCodeAPIBaseURL
        }

        guard URL(string: raw)?.scheme != nil,
              let url = ProviderEndpointOverrideValidator().validatedURL(raw)
        else {
            throw KimiAPIError.invalidRequest("Kimi Code API base URL must use HTTPS without user info")
        }
        return url
    }

    private static func cleaned(_ raw: String?) -> String? {
        guard var value = raw?.trimmingCharacters(in: .whitespacesAndNewlines), !value.isEmpty else {
            return nil
        }

        if (value.hasPrefix("\"") && value.hasSuffix("\"")) ||
            (value.hasPrefix("'") && value.hasSuffix("'"))
        {
            value = String(value.dropFirst().dropLast())
        }

        value = value.trimmingCharacters(in: .whitespacesAndNewlines)
        return value.isEmpty ? nil : value
    }
}