using System.Text;
using Health.Application.HealthArchives;
using Health.Application.HealthRecords;
using Health.Application.Medications;

namespace Health.Application.AI;

public sealed class PatientContextService(
    IHealthArchiveService archives,
    IHealthRecordService healthRecords,
    IMedicationService medications) : IPatientContextService
{
    private readonly IHealthArchiveService _archives = archives;
    private readonly IHealthRecordService _healthRecords = healthRecords;
    private readonly IMedicationService _medications = medications;

    public async Task<string> BuildAsync(Guid userId, CancellationToken ct)
    {
        var archive = await _archives.GetAsync(userId, ct);
        var recentRecords = (await _healthRecords.GetRecordsAsync(userId, null, 30, ct)).Take(10).ToList();
        var activeMedications = await _medications.ListActiveAsync(userId, ct);

        var sb = new StringBuilder();
        if (archive != null)
        {
            if (!string.IsNullOrEmpty(archive.Diagnosis)) sb.AppendLine($"诊断: {archive.Diagnosis}");
            if (archive.Surgeries.Count > 0)
                sb.AppendLine($"手术: {string.Join("；", archive.Surgeries.Select(s => $"{s.Type} ({s.Date})"))}");
            else if (!string.IsNullOrEmpty(archive.SurgeryType))
                sb.AppendLine($"手术: {archive.SurgeryType} ({archive.SurgeryDate})");
            if (archive.ChronicDiseases.Count > 0) sb.AppendLine($"慢病史: {string.Join(", ", archive.ChronicDiseases)}");
            if (!string.IsNullOrEmpty(archive.FamilyHistory)) sb.AppendLine($"家族病史: {archive.FamilyHistory}");
            if (archive.Allergies.Count > 0) sb.AppendLine($"过敏: {string.Join(", ", archive.Allergies)}");
            if (archive.DietRestrictions.Count > 0) sb.AppendLine($"饮食限制: {string.Join(", ", archive.DietRestrictions)}");
        }

        if (activeMedications.Count > 0)
        {
            sb.AppendLine("当前用药:");
            foreach (var medication in activeMedications.Take(20))
            {
                var times = medication.TimeOfDay.Count > 0
                    ? string.Join("/", medication.TimeOfDay.Select(t => t.ToString("HH:mm")))
                    : "未设置时间";
                sb.AppendLine($"  {medication.Name} {medication.Dosage ?? ""} {medication.Frequency} {times}");
            }
        }

        if (recentRecords.Count > 0)
        {
            sb.AppendLine("近期健康数据:");
            foreach (var record in recentRecords)
                sb.AppendLine($"  {record.Type}: {RecordValue(record)} ({record.RecordedAt:MM-dd HH:mm})");
        }

        return sb.ToString();
    }

    private static string RecordValue(HealthRecordDto record) => record.Type switch
    {
        "BloodPressure" => $"{record.Systolic}/{record.Diastolic}",
        "HeartRate" => $"{record.Value}次/分",
        "Glucose" => $"{record.Value}",
        "SpO2" => $"{record.Value}%",
        "Weight" => $"{record.Value}kg",
        _ => "—"
    };
}