using System.Net;
using System.Net.Http.Json;
using System.Text.Json;
using AgriculturalPlatform.Api.Data;
using AgriculturalPlatform.Api.Dtos;
using AgriculturalPlatform.Api.Models;
using AgriculturalPlatform.Api.Services;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace AgriculturalPlatform.Api.Controllers;

[ApiController]
[Route("api/dashboard")]
[Authorize]
public class DashboardController(
    AppDbContext db, DataScopeService scope, CurrentUserService currentUser,
    IHttpClientFactory httpFactory) : ControllerBase
{
    private async Task<IQueryable<PurchaseOrder>> ScopedOrdersAsync()
    {
        var visible = await scope.GetVisibleOrgIdsAsync(currentUser.Get());
        var query = db.PurchaseOrders.AsQueryable();
        if (visible is not null)
            query = query.Where(p => visible.Contains(p.PurchaserOrgId));
        return query;
    }

    /// <summary>解析查询区间：[From, ToExclusive)。未传 from 时默认回溯 days 天。</summary>
    private static (DateTime From, DateTime ToExclusive) ResolveRange(DateTime? from, DateTime? to, int days = 30)
    {
        var end = to?.Date ?? DateTime.Today;
        var start = from?.Date ?? end.AddDays(-(days - 1));
        return (start, end.AddDays(1));
    }

    /// <summary>大屏概览 KPI（按日期区间）</summary>
    [HttpGet("overview")]
    public async Task<ActionResult<OverviewDto>> Overview(DateTime? from, DateTime? to)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var completed = orders.Where(p => p.Status == PurchaseStatus.Completed
            && p.CreatedAt >= start && p.CreatedAt < endEx);

        var amount = await completed.SumAsync(p => (decimal?)p.Amount) ?? 0;
        var count = await orders.CountAsync(p => p.CreatedAt >= start && p.CreatedAt < endEx);
        var netWeight = await completed.SumAsync(p => (decimal?)p.NetWeight) ?? 0;

        var visible = await scope.GetVisibleOrgIdsAsync(currentUser.Get());
        var payQuery = db.PaymentRecords.Where(p => p.Status == PayStatus.Success).AsQueryable();
        if (visible is not null)
            payQuery = payQuery.Where(p => p.PurchaserOrgId != null && visible.Contains(p.PurchaserOrgId.Value));
        var paid = await payQuery
            .Where(p => p.PaidAt >= start && p.PaidAt < endEx)
            .SumAsync(p => (decimal?)p.Amount) ?? 0;

        var avgPrice = netWeight > 0 ? Math.Round(amount / netWeight, 2) : 0;
        var farmerCount = await completed.Select(p => p.FarmerId).Distinct().CountAsync();
        var weighingCount = await orders.CountAsync(p => p.Status == PurchaseStatus.Weighing);

        return Ok(new OverviewDto(amount, count, netWeight, paid, avgPrice, farmerCount, weighingCount));
    }

    /// <summary>区间收购金额/重量趋势（逐日）</summary>
    [HttpGet("trend")]
    public async Task<ActionResult<TrendPoint[]>> Trend(DateTime? from, DateTime? to)
    {
        var (start, endEx) = ResolveRange(from, to, 14);
        var orders = await ScopedOrdersAsync();
        var rows = await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .GroupBy(p => new { p.CreatedAt.Year, p.CreatedAt.Month, p.CreatedAt.Day })
            .Select(g => new { Key = new DateTime(g.Key.Year, g.Key.Month, g.Key.Day), Amount = g.Sum(p => p.Amount), Weight = g.Sum(p => p.NetWeight) })
            .ToListAsync();
        var map = rows.ToDictionary(r => r.Key, r => r);

        var days = (int)(endEx - start).TotalDays;
        var result = Enumerable.Range(0, days).Select(i =>
        {
            var date = start.AddDays(i);
            map.TryGetValue(date, out var row);
            return new TrendPoint(date.ToString("MM-dd"), row?.Amount ?? 0, row?.Weight ?? 0);
        }).ToArray();
        return Ok(result);
    }

    /// <summary>品种收购金额占比</summary>
    [HttpGet("product-distribution")]
    public async Task<ActionResult<RatioPoint[]>> ProductDistribution(DateTime? from, DateTime? to)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var rows = (await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .Select(p => new { p.Product!.Name, p.Amount })
            .ToListAsync())
            .GroupBy(p => p.Name)
            .Select(g => new RatioPoint(g.Key, g.Sum(p => p.Amount)))
            .OrderByDescending(r => r.Value)
            .ToArray();
        return Ok(rows);
    }

    /// <summary>农户收购金额排行</summary>
    [HttpGet("farmer-top")]
    public async Task<ActionResult<FarmerTopPoint[]>> FarmerTop(DateTime? from, DateTime? to, int limit = 8)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var rows = (await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .Select(p => new { p.FarmerId, Name = p.Farmer!.Name, p.Amount, p.NetWeight })
            .ToListAsync())
            .GroupBy(p => new { p.FarmerId, p.Name })
            .Select(g => new FarmerTopPoint(
                g.Key.FarmerId, g.Key.Name,
                g.Sum(p => p.Amount), g.Count(), g.Sum(p => p.NetWeight)))
            .OrderByDescending(r => r.Amount).Take(limit)
            .ToArray();
        return Ok(rows);
    }

    /// <summary>收购方（公司/站/个体）对比</summary>
    [HttpGet("station-comparison")]
    public async Task<ActionResult<StationPoint[]>> StationComparison(DateTime? from, DateTime? to)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var rows = (await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .Select(p => new { p.PurchaserOrgId, Name = p.PurchaserOrg!.Name, p.Amount, p.NetWeight })
            .ToListAsync())
            .GroupBy(p => new { p.PurchaserOrgId, p.Name })
            .Select(g => new StationPoint(
                g.Key.PurchaserOrgId, g.Key.Name,
                g.Sum(p => p.Amount), g.Count(), g.Sum(p => p.NetWeight)))
            .OrderByDescending(r => r.Amount)
            .ToArray();
        return Ok(rows);
    }

    /// <summary>收购单价排行（按品种平均单价）</summary>
    [HttpGet("price-top")]
    public async Task<ActionResult<PriceTopPoint[]>> PriceTop(DateTime? from, DateTime? to, int limit = 8)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var rows = (await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .Select(p => new { Name = p.Product!.Name, p.UnitPrice, p.NetWeight })
            .ToListAsync())
            .GroupBy(p => p.Name)
            .Select(g => new PriceTopPoint(
                g.Key, Math.Round(g.Average(p => p.UnitPrice), 2),
                g.Sum(p => p.NetWeight), g.Count()))
            .OrderByDescending(r => r.AvgPrice).Take(limit)
            .ToArray();
        return Ok(rows);
    }

    /// <summary>农户收入排行（收入 = 区间收购金额，附已付金额）</summary>
    [HttpGet("income-top")]
    public async Task<ActionResult<IncomeTopPoint[]>> IncomeTop(DateTime? from, DateTime? to, int limit = 8)
    {
        var (start, endEx) = ResolveRange(from, to, 30);
        var orders = await ScopedOrdersAsync();
        var farmerRows = (await orders
            .Where(p => p.Status == PurchaseStatus.Completed && p.CreatedAt >= start && p.CreatedAt < endEx)
            .Select(p => new { p.FarmerId, Name = p.Farmer!.Name, p.Amount })
            .ToListAsync())
            .GroupBy(p => p.FarmerId)
            .Select(g => new { FarmerId = g.Key, Name = g.First().Name, Amount = g.Sum(p => p.Amount), Count = g.Count() })
            .ToList();

        var visible = await scope.GetVisibleOrgIdsAsync(currentUser.Get());
        var payQuery = db.PaymentRecords
            .Where(p => p.Status == PayStatus.Success && p.PaidAt >= start && p.PaidAt < endEx).AsQueryable();
        if (visible is not null)
            payQuery = payQuery.Where(p => p.PurchaserOrgId != null && visible.Contains(p.PurchaserOrgId.Value));
        var paidMap = (await payQuery
            .Select(p => new { p.FarmerId, p.Amount })
            .ToListAsync())
            .GroupBy(p => p.FarmerId)
            .ToDictionary(g => g.Key, g => g.Sum(p => p.Amount));

        var result = farmerRows
            .Select(r => new IncomeTopPoint(r.FarmerId, r.Name, r.Amount, paidMap.GetValueOrDefault(r.FarmerId), r.Count))
            .OrderByDescending(r => r.Amount).Take(limit)
            .ToArray();
        return Ok(result);
    }

    /// <summary>实时过磅（进行中的收购单）</summary>
    [HttpGet("realtime-weighing")]
    public async Task<ActionResult<RealtimeWeighing[]>> RealtimeWeighing()
    {
        var orders = await ScopedOrdersAsync();
        var rows = await orders
            .Where(p => p.Status == PurchaseStatus.Weighing)
            .OrderByDescending(p => p.WeighInAt).Take(20)
            .Select(p => new RealtimeWeighing(
                p.Id, p.OrderNo, p.Farmer!.Name, p.Product!.Name,
                p.Status.ToString(), p.GrossWeight, p.WeighInAt))
            .ToListAsync();
        return Ok(rows.ToArray());
    }

    // ---------- 天气（ShowAPI ip-to-weather：IP 定位实时天气） ----------

    /// <summary>ShowAPI 天气中文描述 -> 图标</summary>
    private static string IconFor(string text)
    {
        if (string.IsNullOrEmpty(text)) return "🌡️";
        if (text.Contains("晴")) return "☀️";
        if (text.Contains("雷") || text.Contains("电")) return "⛈️";
        if (text.Contains("雨")) return "🌧️";
        if (text.Contains("雪")) return "🌨️";
        if (text.Contains("多云") || text.Contains("少云") || text.Contains("转")) return "⛅";
        if (text.Contains("阴")) return "☁️";
        if (text.Contains("雾") || text.Contains("霾")) return "🌫️";
        if (text.Contains("风")) return "🌪️";
        if (text.Contains("霜")) return "🥶";
        return "🌡️";
    }

    private static (DateTime Time, WeatherInfo? Data) _weatherCache;

    /// <summary>天气预报：ShowAPI ip-to-weather（按调用方 IP 定位，返回实时天气）</summary>
    [HttpGet("weather")]
    [AllowAnonymous]
    public async Task<ActionResult<WeatherInfo>> Weather()
    {
        if (_weatherCache.Data is not null && DateTime.UtcNow - _weatherCache.Time < TimeSpan.FromMinutes(30))
            return Ok(_weatherCache.Data);

        var client = httpFactory.CreateClient();
        client.Timeout = TimeSpan.FromSeconds(10);

        try
        {
            var ip = await ResolveClientIpAsync(client);

            // ShowAPI ip-to-weather：必须携带 ip 参数，Authorization 头带 AppCode
            using var request = new HttpRequestMessage(HttpMethod.Get,
                $"https://ali-weather.showapi.com/ip-to-weather?ip={Uri.EscapeDataString(ip)}");
            request.Headers.TryAddWithoutValidation("Authorization", "APPCODE e3bdae1a73d2415492e7fdc024f07d08");
            using var resp = await client.SendAsync(request);
            resp.EnsureSuccessStatusCode();
            using var doc = JsonDocument.Parse(await resp.Content.ReadAsStringAsync());

            var root = doc.RootElement;
            if (root.TryGetProperty("showapi_res_code", out var rc) && rc.GetInt32() != 0)
                return StatusCode(502, new
                {
                    message = "天气服务暂不可用",
                    detail = root.TryGetProperty("showapi_res_error", out var re) ? re.GetString() : "未知错误"
                });

            var body = root.GetProperty("showapi_res_body");
            var cityInfo = body.GetProperty("cityInfo");
            var now = body.GetProperty("now");
            var today = body.TryGetProperty("f1", out var f1) ? f1 : default;

            var city = cityInfo.TryGetProperty("c3", out var c) ? c.GetString() ?? "" : "";
            var region = cityInfo.TryGetProperty("c7", out var p) ? p.GetString() ?? "" : "";

            var text = now.TryGetProperty("weather", out var w) ? w.GetString() ?? "" : "";
            if (string.IsNullOrEmpty(text)) text = "未知";

            var temp = ParseWeatherNumber(now, "temperature");
            var feels = ParseWeatherNumber(now, "feels_like");
            var humidity = ParseWeatherNumber(now, "sd");
            var wind = $"{GetWeatherField(now, "wind_direction")} {GetWeatherField(now, "wind_power")}".Trim();

            var min = today.ValueKind == JsonValueKind.Object ? ParseWeatherNumber(today, "night_air_temperature") : temp;
            var max = today.ValueKind == JsonValueKind.Object ? ParseWeatherNumber(today, "day_air_temperature") : temp;

            var result = new WeatherInfo(
                city, region, text, IconFor(text),
                temp, feels, humidity, wind,
                min, max, DateTime.Now, "ShowAPI");

            _weatherCache = (DateTime.UtcNow, result);
            return Ok(result);
        }
        catch (Exception ex)
        {
            return StatusCode(502, new { message = "天气服务暂不可用", detail = ex.Message });
        }
    }

    /// <summary>解析调用方 IP：代理转发头 -> 直连 IP -> 本机公网 IP 兜底（本地开发时用）</summary>
    private async Task<string> ResolveClientIpAsync(HttpClient client)
    {
        var fwd = Request.Headers["X-Forwarded-For"].FirstOrDefault();
        if (!string.IsNullOrEmpty(fwd))
        {
            var ip = fwd.Split(',')[0].Trim();
            if (!IsPrivateIp(ip)) return ip;
        }
        var remote = HttpContext.Connection.RemoteIpAddress?.MapToIPv4().ToString() ?? "";
        if (!IsPrivateIp(remote)) return remote;

        try { return (await client.GetStringAsync("http://ip.3322.net")).Trim(); }
        catch { return remote.Length > 0 ? remote : "0.0.0.0"; }
    }

    private static bool IsPrivateIp(string ip)
    {
        if (string.IsNullOrEmpty(ip) || ip == "::1") return true;
        if (!IPAddress.TryParse(ip, out var addr)) return true;
        var bytes = addr.GetAddressBytes();
        if (bytes.Length != 4) return true; // 仅处理 IPv4
        return bytes[0] == 10
            || bytes[0] == 127
            || (bytes[0] == 192 && bytes[1] == 168)
            || (bytes[0] == 172 && bytes[1] is >= 16 and <= 31)
            || bytes[0] == 0;
    }

    /// <summary>读取数值型天气字段（容忍"25℃"、"50%"等后缀）</summary>
    private static decimal ParseWeatherNumber(JsonElement obj, string prop)
    {
        if (!obj.TryGetProperty(prop, out var el)) return 0;
        var raw = el.ValueKind == JsonValueKind.String ? el.GetString() : el.ToString();
        if (string.IsNullOrEmpty(raw)) return 0;
        var num = new string(raw.TakeWhile(ch => char.IsDigit(ch) || ch == '-' || ch == '.').ToArray());
        return decimal.TryParse(num, out var v) ? v : 0;
    }

    /// <summary>读取天气字符串字段</summary>
    private static string GetWeatherField(JsonElement obj, string prop)
    {
        if (obj.TryGetProperty(prop, out var el) && el.ValueKind == JsonValueKind.String)
            return el.GetString() ?? "";
        return "";
    }
}