using Microsoft.AspNetCore.Mvc;
using WenChuanyi.Api.Dtos;
using WenChuanyi.Api.Models;
using WenChuanyi.Api.Services;

namespace WenChuanyi.Api.Controllers;

/// <summary>开放 API：按服务端文件路径上传（共享/私密/标签）+ 下载链接查询</summary>
[ApiController]
[Route("api/open")]
public class OpenApiController : ControllerBase
{
    private readonly IFreeSql _fsql;
    private readonly CodeGeneratorService _codeGen;
    private readonly OssStorageService _oss;
    private readonly string _baseUrl;
    private readonly string _uploadRoot;
    private readonly ILogger<OpenApiController> _logger;

    public OpenApiController(IFreeSql fsql, CodeGeneratorService codeGen, OssStorageService oss,
        IConfiguration cfg, ILogger<OpenApiController> logger)
    {
        _fsql = fsql;
        _codeGen = codeGen;
        _oss = oss;
        _baseUrl = cfg["App:BaseUrl"] ?? "";
        _uploadRoot = Path.GetFullPath(cfg["OpenApi:UploadRoot"] ?? throw new InvalidOperationException("缺少配置 OpenApi:UploadRoot"));
        _logger = logger;
    }

    /// <summary>公开上传-共享：expiresHours（0=永久，缺省 24）；pwd/tag 可同时提供（不互斥）</summary>
    [HttpPost("upload-public")]
    public Task<IActionResult> UploadPublic([FromBody] OpenUploadRequest req)
        => UploadFromPathAsync(req.FilePath, req.ExpiresHours, req.Pwd, req.Tag);

    /// <summary>公开上传-私密：必填密码，可同时带标签</summary>
    [HttpPost("upload-price")]
    public Task<IActionResult> UploadPrice([FromBody] OpenUploadPriceRequest req)
        => UploadFromPathAsync(req.FilePath, null, req.Pwd, req.Tag);

    /// <summary>公开上传-标签：必填标签（永久保存），可同时带密码</summary>
    [HttpPost("upload-tag")]
    public Task<IActionResult> UploadTag([FromBody] OpenUploadTagRequest req)
        => UploadFromPathAsync(req.FilePath, null, req.Pwd, req.Tag);

    /// <summary>公开下载链接查询：共享/标签返回直接下载 URL，私密跳取件页手动输密码</summary>
    [HttpGet("download/{pickCode}")]
    public async Task<IActionResult> Download(string pickCode)
    {
        if (pickCode.Length is not (6 or 8) || !pickCode.All(char.IsDigit))
        {
            return NotFound(new { message = "取件码无效" });
        }
        var item = await _fsql.Select<FileItem>().Where(f => f.PickCode == pickCode).FirstAsync();
        if (item == null)
        {
            return NotFound(new { message = "取件码无效" });
        }
        if (!item.IsPermanent && item.ExpiresAt != null && item.ExpiresAt < DateTime.Now)
        {
            return StatusCode(410, new { message = "文件已过期" });
        }
        var needPassword = item.FileType == "private";
        return Ok(new OpenDownloadResult
        {
            PickUrl = BuildPickUrl(pickCode),
            DownloadUrl = needPassword ? BuildPickUrl(pickCode) : BuildDownloadUrl(pickCode),
            NeedPassword = needPassword
        });
    }

    // ---------- 私有 ----------

    private async Task<IActionResult> UploadFromPathAsync(string filePath, long? expiresHours, string? pwd, string? tag)
    {
        var fullPath = ResolveSafePath(filePath);
        if (fullPath == null)
        {
            return BadRequest(new { message = "文件路径不在白名单目录内" });
        }
        if (!System.IO.File.Exists(fullPath))
        {
            return NotFound(new { message = "文件不存在" });
        }
        var fi = new FileInfo(fullPath);
        if (fi.Length > FileRules.MaxFileBytes)
        {
            return BadRequest(new { message = "文件超过 200MB 限制" });
        }

        var pwdErr = FileRules.ValidatePassword(pwd);
        if (pwdErr != null) return BadRequest(new { message = pwdErr });

        tag = string.IsNullOrWhiteSpace(tag) ? null : tag.Trim();
        var tagErr = FileRules.ValidateTag(tag);
        if (tagErr != null) return BadRequest(new { message = tagErr });

        var hasPassword = !string.IsNullOrEmpty(pwd);
        var hasTag = !string.IsNullOrEmpty(tag);
        var isPermanent = hasTag || expiresHours == 0;
        DateTime? expiresAt = isPermanent ? null : DateTime.Now.AddHours(expiresHours ?? 24);

        var fileType = FileRules.ResolveFileType(hasPassword, hasTag);
        var objectKey = _oss.BuildObjectKey(fi.Name);
        var ip = HttpContext.Connection.RemoteIpAddress?.ToString();

        try
        {
            await using var stream = System.IO.File.OpenRead(fullPath);
            await _oss.UploadAsync(objectKey, stream, "application/octet-stream");
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "公开上传 OSS 失败：{Path}", fullPath);
            return StatusCode(500, new { message = "文件上传失败" });
        }

        var item = new FileItem
        {
            PickCode = await _codeGen.GeneratePickCodeAsync(FileRules.PickCodeLength(fileType)),
            AdminCode = await _codeGen.GenerateAdminCodeAsync(),
            FileType = fileType,
            Password = hasPassword ? pwd : null,
            Tag = hasTag ? tag : null,
            OriginalName = fi.Name,
            ObjectKey = objectKey,
            Size = fi.Length,
            MimeType = "application/octet-stream",
            DownloadCount = 0,
            UploadIp = ip,
            IsPermanent = isPermanent,
            ExpiresAt = expiresAt,
            CreatedAt = DateTime.Now
        };
        await _fsql.Insert(item).ExecuteAffrowsAsync();

        return Ok(new OpenResult
        {
            PickCode = item.PickCode,
            PickUrl = BuildPickUrl(item.PickCode),
            DownloadUrl = fileType == "private" ? BuildPickUrl(item.PickCode) : BuildDownloadUrl(item.PickCode)
        });
    }

    /// <summary>路径规范化 + 白名单前缀校验，防路径穿越</summary>
    private string? ResolveSafePath(string filePath)
    {
        if (string.IsNullOrWhiteSpace(filePath)) return null;
        var full = Path.GetFullPath(filePath);
        if (!full.StartsWith(_uploadRoot, StringComparison.OrdinalIgnoreCase)) return null;
        return full;
    }

    private string BuildPickUrl(string pickCode) => $"{_baseUrl}/#/pickup?code={pickCode}";
    private string BuildDownloadUrl(string pickCode) => $"{_baseUrl}/api/files/{pickCode}/download";
}