using System.Security.Claims;
using AgriculturalPlatform.Api.Data;
using AgriculturalPlatform.Api.Dtos;
using AgriculturalPlatform.Api.Models;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace AgriculturalPlatform.Api.Controllers;

/// <summary>通知公告</summary>
[ApiController]
[Route("api/announcements")]
[Authorize]
public class AnnouncementsController(AppDbContext db) : ControllerBase
{
    private int UserId => int.Parse(User.FindFirstValue(ClaimTypes.NameIdentifier) ?? "0");

    /// <summary>我的公告列表（含已读状态、未读数）</summary>
    [HttpGet("my")]
    public async Task<ActionResult> My([FromQuery] int page = 1, [FromQuery] int pageSize = 10)
    {
        var uid = UserId;
        var query = db.Announcements.AsNoTracking();
        // 范围过滤：空范围=全员可见；含本人组织
        var orgId = await db.Users.Where(u => u.Id == uid).Select(u => u.OrgId).FirstOrDefaultAsync();
        var queryFiltered = query.Where(a => a.ScopeOrgIds == "" || (orgId != null && a.ScopeOrgIds.Split(',', StringSplitOptions.RemoveEmptyEntries).Contains(orgId.ToString())));

        var total = await queryFiltered.CountAsync();
        var items = await queryFiltered.OrderByDescending(a => a.IsPinned).ThenByDescending(a => a.PublishedAt)
            .Skip((page - 1) * pageSize).Take(pageSize)
            .Select(a => new
            {
                a.Id, a.Title, a.Content, a.Type, a.ScopeOrgIds, a.IsPinned,
                PublisherName = a.Publisher != null ? a.Publisher.RealName : "",
                a.PublishedAt, a.CreatedAt,
                IsRead = db.AnnouncementReads.Any(r => r.AnnouncementId == a.Id && r.UserId == uid)
            })
            .ToListAsync();

        var unread = await queryFiltered
            .CountAsync(a => !db.AnnouncementReads.Any(r => r.AnnouncementId == a.Id && r.UserId == uid));
        return Ok(new { items, total, unread });
    }

    /// <summary>未读公告数（顶栏徽标）</summary>
    [HttpGet("unread-count")]
    public async Task<ActionResult> UnreadCount()
    {
        var uid = UserId;
        var orgId = await db.Users.Where(u => u.Id == uid).Select(u => u.OrgId).FirstOrDefaultAsync();
        var count = await db.Announcements.CountAsync(a =>
            (a.ScopeOrgIds == "" || (orgId != null && a.ScopeOrgIds.Split(',', StringSplitOptions.RemoveEmptyEntries).Contains(orgId.ToString())))
            && !db.AnnouncementReads.Any(r => r.AnnouncementId == a.Id && r.UserId == uid));
        return Ok(new { count });
    }

    /// <summary>公告详情（标记已读）</summary>
    [HttpGet("{id:int}")]
    public async Task<ActionResult> Get(int id)
    {
        var uid = UserId;
        var a = await db.Announcements.Include(x => x.Publisher).FirstOrDefaultAsync(x => x.Id == id);
        if (a is null) return NotFound();

        // 标记已读
        if (!await db.AnnouncementReads.AnyAsync(r => r.AnnouncementId == id && r.UserId == uid))
        {
            db.AnnouncementReads.Add(new AnnouncementRead { AnnouncementId = id, UserId = uid, ReadAt = DateTime.Now });
            await db.SaveChangesAsync();
        }
        var dto = new AnnouncementDto(a.Id, a.Title, a.Content, a.Type, a.ScopeOrgIds, a.IsPinned,
            a.Publisher?.RealName ?? "", a.PublishedAt, a.CreatedAt, true);
        return Ok(dto);
    }

    /// <summary>全部公告（管理端）</summary>
    [HttpGet]
    public async Task<ActionResult<PagedResult<AnnouncementDto>>> List(string? keyword, string? type, [FromQuery] int page = 1, [FromQuery] int pageSize = 20)
    {
        var uid = UserId;
        var query = db.Announcements.AsNoTracking();
        if (!string.IsNullOrWhiteSpace(keyword))
            query = query.Where(a => a.Title.Contains(keyword) || a.Content.Contains(keyword));
        if (!string.IsNullOrWhiteSpace(type))
            query = query.Where(a => a.Type == type);

        var total = await query.CountAsync();
        var items = await query.OrderByDescending(a => a.PublishedAt)
            .Skip((page - 1) * pageSize).Take(pageSize)
            .Select(a => new AnnouncementDto(
                a.Id, a.Title, a.Content, a.Type, a.ScopeOrgIds, a.IsPinned,
                a.Publisher != null ? a.Publisher.RealName : "",
                a.PublishedAt, a.CreatedAt,
                db.AnnouncementReads.Any(r => r.AnnouncementId == a.Id && r.UserId == uid)))
            .ToListAsync();
        return Ok(new PagedResult<AnnouncementDto>(items, total));
    }

    /// <summary>发布公告</summary>
    [HttpPost]
    public async Task<ActionResult> Create(AnnouncementSaveRequest req)
    {
        if (string.IsNullOrWhiteSpace(req.Title))
            return BadRequest(new { message = "标题不能为空" });
        var a = new Announcement
        {
            Title = req.Title, Content = req.Content ?? "", Type = req.Type,
            ScopeOrgIds = req.ScopeOrgIds ?? "", IsPinned = req.IsPinned,
            PublisherId = UserId, PublishedAt = DateTime.Now, CreatedAt = DateTime.Now
        };
        db.Announcements.Add(a);
        await db.SaveChangesAsync();
        return Ok(new { message = "发布成功", id = a.Id });
    }

    /// <summary>修改公告</summary>
    [HttpPut("{id:int}")]
    public async Task<ActionResult> Update(int id, AnnouncementSaveRequest req)
    {
        var a = await db.Announcements.FindAsync(id);
        if (a is null) return NotFound();
        a.Title = req.Title; a.Content = req.Content ?? ""; a.Type = req.Type;
        a.ScopeOrgIds = req.ScopeOrgIds ?? ""; a.IsPinned = req.IsPinned;
        await db.SaveChangesAsync();
        return Ok(new { message = "保存成功" });
    }

    /// <summary>删除公告</summary>
    [HttpDelete("{id:int}")]
    public async Task<IActionResult> Delete(int id)
    {
        var a = await db.Announcements.FindAsync(id);
        if (a is null) return NotFound();
        db.Announcements.Remove(a);
        await db.SaveChangesAsync();
        return Ok(new { message = "删除成功" });
    }
}