package logic

import (
	"context"
	"database/sql"
	"fmt"

	"git.cialloo.com/CiallooWeb/Blog/app/internal/svc"
	"git.cialloo.com/CiallooWeb/Blog/app/internal/types"

	"github.com/zeromicro/go-zero/core/logx"
)

type CreatePostLogic struct {
	logx.Logger
	ctx    context.Context
	svcCtx *svc.ServiceContext
}

// Create a new blog post
func NewCreatePostLogic(ctx context.Context, svcCtx *svc.ServiceContext) *CreatePostLogic {
	return &CreatePostLogic{
		Logger: logx.WithContext(ctx),
		ctx:    ctx,
		svcCtx: svcCtx,
	}
}

func (l *CreatePostLogic) CreatePost(req *types.CreatePostReq) (resp *types.CreatePostResp, err error) {
	var coverID sql.NullInt64

	// If cover image key is provided, move it from tmpfiles to files table
	if req.CoverImageKey != "" {
		// Start a transaction
		tx, err := l.svcCtx.DB.BeginTx(l.ctx, nil)
		if err != nil {
			l.Errorf("Failed to begin transaction: %v", err)
			return nil, err
		}
		defer tx.Rollback()

		// Get the tmpfile record
		var fileName string
		tmpQuery := `SELECT file_name FROM tmpfiles WHERE key = $1`
		err = tx.QueryRowContext(l.ctx, tmpQuery, req.CoverImageKey).Scan(&fileName)
		if err != nil {
			if err == sql.ErrNoRows {
				l.Errorf("Cover image not found in tmpfiles with key: %s", req.CoverImageKey)
				return nil, fmt.Errorf("cover image not found")
			}
			l.Errorf("Failed to get tmpfile: %v", err)
			return nil, err
		}

		// Insert into files table
		fileQuery := `INSERT INTO files (file_name, file_key) VALUES ($1, $2) RETURNING id`
		err = tx.QueryRowContext(l.ctx, fileQuery, fileName, req.CoverImageKey).Scan(&coverID.Int64)
		if err != nil {
			l.Errorf("Failed to insert file record: %v", err)
			return nil, err
		}
		coverID.Valid = true

		// Delete from tmpfiles
		deleteQuery := `DELETE FROM tmpfiles WHERE key = $1`
		_, err = tx.ExecContext(l.ctx, deleteQuery, req.CoverImageKey)
		if err != nil {
			l.Errorf("Failed to delete tmpfile: %v", err)
			return nil, err
		}

		// Insert new post
		var postID int64
		postQuery := `INSERT INTO posts (title, content, cover_id) VALUES ($1, $2, $3) RETURNING id`
		err = tx.QueryRowContext(l.ctx, postQuery, req.Title, req.Content, coverID).Scan(&postID)
		if err != nil {
			l.Errorf("Failed to create post: %v", err)
			return nil, err
		}

		// Commit transaction
		if err = tx.Commit(); err != nil {
			l.Errorf("Failed to commit transaction: %v", err)
			return nil, err
		}

		return &types.CreatePostResp{
			PostId: fmt.Sprintf("%d", postID),
		}, nil
	}

	// No cover image - just insert the post
	var postID int64
	query := `INSERT INTO posts (title, content, cover_id) VALUES ($1, $2, $3) RETURNING id`
	err = l.svcCtx.DB.QueryRowContext(l.ctx, query, req.Title, req.Content, coverID).Scan(&postID)
	if err != nil {
		l.Errorf("Failed to create post: %v", err)
		return nil, err
	}

	return &types.CreatePostResp{
		PostId: fmt.Sprintf("%d", postID),
	}, nil
}