am-downloader/handlers.go

package main

import (
	"io"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"
)

func (a *App) search(c *gin.Context) {
	keyword := strings.TrimSpace(c.Query("keyword"))
	if keyword == "" {
		c.JSON(400, gin.H{"error": "keyword required"})
		return
	}
	source := c.DefaultQuery("source", "kw")
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	if page < 1 {
		page = 1
	}
	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
	if limit < 1 {
		limit = 20
	}
	resp, err := a.am.Search(keyword, source, page, limit)
	if err != nil {
		c.JSON(502, gin.H{"error": err.Error()})
		return
	}
	defer resp.Body.Close()
	c.Status(resp.StatusCode)
	_, _ = io.Copy(c.Writer, resp.Body)
}

func (a *App) listTasks(c *gin.Context) {
	var ts []Task
	user := c.MustGet("user").(*User)
	query := a.db.Where("user_id = ?", user.ID)
	if user.Role == RoleAdmin && c.Query("all") == "1" {
		query = a.db
	}
	if err := query.Order("id desc").Limit(100).Find(&ts).Error; err != nil {
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	c.JSON(200, gin.H{"data": ts})
}

func (a *App) addTask(c *gin.Context) {
	var in SongRequest
	if c.BindJSON(&in) != nil || in.RID == "" || in.Title == "" {
		c.JSON(400, gin.H{"error": "source/rid/title required"})
		return
	}
	if in.Source == "" {
		in.Source = "kw"
	}
	if in.Quality == "" {
		in.Quality = a.cfg.DefaultQuality
	}
	user := c.MustGet("user").(*User)
	var existing Task
	err := a.db.Where("user_id = ? AND source = ? AND r_id = ? AND quality = ?", user.ID, in.Source, in.RID, in.Quality).Order("id desc").First(&existing).Error
	if err == nil {
		if existing.Status != "error" {
			c.JSON(200, existing)
			return
		}
		r, reserveErr := a.reserveCredit(user.ID, existing.ID, 1)
		if reserveErr != nil {
			c.JSON(402, gin.H{"error": reserveErr.Error()})
			return
		}
		a.db.Model(&existing).Updates(map[string]any{"title": in.Title, "artist": in.Artist, "album": in.Album, "pic": in.Pic, "status": "pending", "error": "", "credit_reservation_id": r.ID})
		existing.CreditReservationID = r.ID
		a.queue <- existing.ID
		c.JSON(202, existing)
		return
	}
	t := Task{UserID: user.ID, Source: in.Source, RID: in.RID, Title: in.Title, Artist: in.Artist, Album: in.Album, Pic: in.Pic, Quality: in.Quality, Status: "pending"}
	if err := a.db.Create(&t).Error; err != nil {
		if a.db.Where("user_id = ? AND source = ? AND r_id = ? AND quality = ?", user.ID, in.Source, in.RID, in.Quality).Order("id desc").First(&existing).Error == nil {
			c.JSON(200, existing)
			return
		}
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	r, reserveErr := a.reserveCredit(user.ID, t.ID, 1)
	if reserveErr != nil {
		_ = a.db.Delete(&t).Error
		c.JSON(402, gin.H{"error": reserveErr.Error()})
		return
	}
	t.CreditReservationID = r.ID
	if err := a.db.Model(&t).Update("credit_reservation_id", r.ID).Error; err != nil {
		_ = a.refundCredit(&t)
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	a.queue <- t.ID
	c.JSON(202, t)
}

func (a *App) creditInfo(c *gin.Context) {
	user := c.MustGet("user").(*User)
	account, err := a.creditBalance(user.ID)
	if err != nil {
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	c.JSON(200, gin.H{"balance": account.Balance, "reserved": account.Reserved, "available": account.Balance - account.Reserved})
}

func (a *App) retryTask(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.Status(400)
		return
	}
	var t Task
	user := c.MustGet("user").(*User)
	if a.db.Where("id = ? AND user_id = ?", id, user.ID).First(&t).Error != nil {
		c.Status(404)
		return
	}
	if t.Status != "error" {
		c.JSON(409, gin.H{"error": "only failed tasks can be retried"})
		return
	}
	r, reserveErr := a.reserveCredit(user.ID, t.ID, 1)
	if reserveErr != nil {
		c.JSON(402, gin.H{"error": reserveErr.Error()})
		return
	}
	if err := a.db.Model(&t).Updates(map[string]any{"status": "pending", "error": "", "progress": 0, "downloaded_bytes": 0, "credit_reservation_id": r.ID}).Error; err != nil {
		_ = a.refundCredit(&Task{ID: t.ID, UserID: user.ID, CreditReservationID: r.ID})
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	t.Status, t.Error, t.Progress, t.DownloadedBytes, t.CreditReservationID = "pending", "", 0, 0, r.ID
	a.queue <- t.ID
	c.JSON(202, t)
}

func (a *App) deleteTask(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		c.Status(400)
		return
	}
	user := c.MustGet("user").(*User)
	var t Task
	if err := a.db.Where("id = ? AND user_id = ?", id, user.ID).First(&t).Error; err != nil {
		c.Status(404)
		return
	}
	if t.CreditReservationID != 0 {
		if err := a.refundCredit(&t); err != nil {
			c.JSON(409, gin.H{"error": "cannot release task credit: " + err.Error()})
			return
		}
	}
	if err := a.db.Delete(&t).Error; err != nil {
		c.JSON(500, gin.H{"error": err.Error()})
		return
	}
	c.Status(204)
}