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>角色管理（RBAC）</summary>
[ApiController]
[Route("api/roles")]
[Authorize]
public class RolesController(AppDbContext db) : ControllerBase
{
    /// <summary>角色列表</summary>
    [HttpGet]
    public async Task<ActionResult<PagedResult<RoleDto>>> List(string? keyword, [FromQuery] int page = 1, [FromQuery] int pageSize = 20)
    {
        var query = db.SysRoles.AsQueryable();
        if (!string.IsNullOrWhiteSpace(keyword))
            query = query.Where(r => r.Name.Contains(keyword) || r.Code.Contains(keyword));

        var total = await query.CountAsync();
        var items = await query.OrderBy(r => r.Id)
            .Skip((page - 1) * pageSize).Take(pageSize)
            .Select(r => new RoleDto(
                r.Id, r.Name, r.Code, r.Description, r.IsSystem,
                db.SysRoleMenus.Where(rm => rm.RoleId == r.Id).Select(rm => rm.MenuId).ToArray()))
            .ToListAsync();
        return Ok(new PagedResult<RoleDto>(items, total));
    }

    /// <summary>全部角色（下拉选择用）</summary>
    [HttpGet("all")]
    public async Task<ActionResult> All()
    {
        var items = await db.SysRoles.AsNoTracking().OrderBy(r => r.Id)
            .Select(r => new { r.Id, r.Name, r.Code }).ToListAsync();
        return Ok(items);
    }

    /// <summary>新增角色</summary>
    [HttpPost]
    public async Task<ActionResult> Create(RoleSaveRequest req)
    {
        if (string.IsNullOrWhiteSpace(req.Code))
            return BadRequest(new { message = "角色编码不能为空" });
        if (await db.SysRoles.AnyAsync(r => r.Code == req.Code.Trim()))
            return BadRequest(new { message = "角色编码已存在" });

        var role = new SysRole
        {
            Name = req.Name, Code = req.Code.Trim(), Description = req.Description, CreatedAt = DateTime.Now
        };
        db.SysRoles.Add(role);
        await db.SaveChangesAsync();

        if (req.MenuIds.Length > 0)
        {
            db.SysRoleMenus.AddRange(req.MenuIds.Distinct().Select(mid => new SysRoleMenu { RoleId = role.Id, MenuId = mid }));
            await db.SaveChangesAsync();
        }
        return Ok(new { message = "保存成功", id = role.Id });
    }

    /// <summary>修改角色</summary>
    [HttpPut("{id:int}")]
    public async Task<ActionResult> Update(int id, RoleSaveRequest req)
    {
        var role = await db.SysRoles.FindAsync(id);
        if (role is null) return NotFound();

        role.Name = req.Name; role.Description = req.Description;
        // 系统内置角色编码不可改
        if (!role.IsSystem) role.Code = req.Code.Trim();

        var old = await db.SysRoleMenus.Where(rm => rm.RoleId == id).Select(rm => rm.MenuId).ToListAsync();
        var newMenuIds = req.MenuIds.Distinct().ToArray();
        var toRemove = old.Where(m => !newMenuIds.Contains(m)).ToList();
        var toAdd = newMenuIds.Where(m => !old.Contains(m)).ToList();
        if (toRemove.Count > 0)
            db.SysRoleMenus.RemoveRange(toRemove.Select(m => new SysRoleMenu { RoleId = id, MenuId = m }));
        if (toAdd.Count > 0)
            db.SysRoleMenus.AddRange(toAdd.Select(m => new SysRoleMenu { RoleId = id, MenuId = m }));

        await db.SaveChangesAsync();
        return Ok(new { message = "保存成功" });
    }

    /// <summary>删除角色（系统内置或有用户引用时禁止删除）</summary>
    [HttpDelete("{id:int}")]
    public async Task<IActionResult> Delete(int id)
    {
        var role = await db.SysRoles.FindAsync(id);
        if (role is null) return NotFound();
        if (role.IsSystem) return BadRequest(new { message = "系统内置角色不可删除" });
        if (await db.Users.AnyAsync(u => u.RoleId == id))
            return BadRequest(new { message = "该角色已被用户使用，请先解除关联" });

        db.SysRoleMenus.RemoveRange(db.SysRoleMenus.Where(rm => rm.RoleId == id));
        db.SysRoles.Remove(role);
        await db.SaveChangesAsync();
        return Ok(new { message = "删除成功" });
    }
}