using CareFix.Api.Ai;
using CareFix.Api.Options;
using Dapper;
using Microsoft.Extensions.Options;

namespace CareFix.Api.Infrastructure;

/// <summary>What a monitoring tool or an admin needs to know at a glance.</summary>
public sealed class HealthService(ControlDb db, AiUsageService usage, IOptions<CareFixOptions> options)
{
    /// <summary>Anonymous liveness check: is the service up and can it reach its own database?</summary>
    public async Task<(bool Ok, object Body)> LivenessAsync(CancellationToken ct)
    {
        try
        {
            await using var c = await db.OpenAsync(ct);
            await c.ExecuteScalarAsync<int>("SELECT 1");
            return (true, new { status = "ok", at = DateTime.UtcNow });
        }
        catch (Exception ex)
        {
            return (false, new { status = "down", reason = ex.GetType().Name, at = DateTime.UtcNow });
        }
    }

    /// <summary>Full picture for admins: work in flight, agents, integration backlog, AI spend.</summary>
    public async Task<object> DetailAsync(CancellationToken ct)
    {
        await using var c = await db.OpenAsync(ct);
        using var m = await c.QueryMultipleAsync("""
            SELECT (SELECT COUNT(*) FROM CF_TICKET WHERE State <> 'Closed') AS OpenTickets,
                   (SELECT COUNT(*) FROM CF_TICKET WHERE AiBusy = 1) AS AiBusy,
                   (SELECT COUNT(*) FROM CF_FIX WHERE State = 'Proposed') AS AwaitingApproval,
                   (SELECT COUNT(*) FROM CF_FIX WHERE State = 'Approved') AS ReadyToRun;
            SELECT (SELECT COUNT(*) FROM CF_HOSPITAL WHERE Status = 'Active') AS ActiveHospitals,
                   (SELECT COUNT(*) FROM CF_HOSPITAL h WHERE h.Status = 'Active' AND h.SchemaCapturedAt IS NULL) AS SchemaMissing,
                   (SELECT COUNT(*) FROM CF_AGENT WHERE LastSeenAt > DATEADD(MINUTE, -2, SYSUTCDATETIME())) AS AgentsOnline,
                   (SELECT COUNT(*) FROM CF_AGENT WHERE LastSeenAt IS NULL OR LastSeenAt <= DATEADD(MINUTE, -2, SYSUTCDATETIME())) AS AgentsOffline,
                   (SELECT COUNT(*) FROM CF_AGENT_JOB WHERE State = 'Pending') AS AgentJobsWaiting;
            SELECT (SELECT COUNT(*) FROM CF_WEBHOOK_OUTBOX WHERE State = 'Pending') AS WebhooksPending,
                   (SELECT COUNT(*) FROM CF_WEBHOOK_OUTBOX WHERE State = 'Failed') AS WebhooksFailed,
                   (SELECT COUNT(*) FROM CF_MINE_BATCH WHERE State IN ('Queued','Processing')) AS LearningRunning;
            SELECT TOP 1 At FROM CF_AUDIT WHERE Action = 'MaintenanceRun' ORDER BY EventId DESC;
            SELECT TOP 5 h.Name, a.LastSeenAt FROM CF_AGENT a JOIN CF_HOSPITAL h ON h.HospitalId = a.HospitalId
             WHERE h.Status = 'Active' AND (a.LastSeenAt IS NULL OR a.LastSeenAt <= DATEADD(MINUTE, -2, SYSUTCDATETIME()))
             ORDER BY a.LastSeenAt;
            """);
        var work = await m.ReadSingleAsync();
        var hospitals = await m.ReadSingleAsync();
        var queues = await m.ReadSingleAsync();
        var lastMaintenance = await m.ReadSingleOrDefaultAsync<DateTime?>();
        var offlineAgents = await m.ReadAsync();

        var cfg = options.Value;
        var spent = await usage.MonthToDateAsync(ct);
        return new
        {
            status = "ok",
            at = DateTime.UtcNow,
            work,
            hospitals,
            queues,
            offlineAgents,
            lastMaintenance,
            ai = new
            {
                model = cfg.Claude.Model,
                apiKeySet = !string.IsNullOrWhiteSpace(cfg.Claude.ApiKey),
                monthToDateUsd = spent,
                monthlyBudgetUsd = cfg.Claude.MonthlyBudgetUsd,
                budgetReached = cfg.Claude.MonthlyBudgetUsd > 0 && spent >= cfg.Claude.MonthlyBudgetUsd,
            },
            integration = new
            {
                inboundApi = !string.IsNullOrWhiteSpace(cfg.Integration.InboundKey),
                outboundWebhook = !string.IsNullOrWhiteSpace(cfg.Integration.WebhookUrl),
            },
        };
    }
}