package handlers

import (
    "log"
    "fmt"
    "mime"
    "net/http"
    "path/filepath"
    "strings"
    "time"

    "github.com/gin-gonic/gin"

    "go-dy/internal/config"
    osspkg "go-dy/internal/oss"
    "go-dy/internal/resp"
)

func UploadHandler(cfg config.Config) gin.HandlerFunc {
    return func(c *gin.Context) {
        fileHeader, err := c.FormFile("file")
        if err != nil {
            resp.Error(c, http.StatusBadRequest, "missing file")
            return
        }
        f, err := fileHeader.Open()
        if err != nil {
            log.Printf("file open failed: filename=%s, err=%v", fileHeader.Filename, err)
            resp.Error(c, http.StatusInternalServerError, "file open failed")
            return
        }
        defer f.Close()

        prefix := c.PostForm("prefix")
        prefix = strings.Trim(prefix, "/ ")
        if prefix == "" {
            prefix = time.Now().Format("uploads/2006/01/02")
        }

        base := filepath.Base(fileHeader.Filename)
        ts := time.Now().UnixNano()
        objectKey := fmt.Sprintf("%s/%d_%s", prefix, ts, base)

        ct := fileHeader.Header.Get("Content-Type")
        if ct == "" {
            ct = mime.TypeByExtension(filepath.Ext(base))
        }

        // Lazy init OSS client to avoid startup dependency on OSS params
        oss, err := osspkg.New(cfg)
        if err != nil {
            log.Printf("oss init failed: endpoint=%s bucket=%s err=%v", cfg.OSSEndpoint, cfg.OSSBucket, err)
            resp.Error(c, http.StatusInternalServerError, "upload failed")
            return
        }
        if err := oss.Upload(objectKey, f, ct); err != nil {
            log.Printf("oss upload failed: key=%s contentType=%s err=%v", objectKey, ct, err)
            resp.Error(c, http.StatusInternalServerError, "upload failed")
            return
        }

        url := oss.PublicURL(objectKey)
        log.Printf("oss upload success: key=%s url=%s", objectKey, url)
        resp.OK(c, gin.H{
            "key": objectKey,
            "url": url,
        })
    }
}