package cron

import (
	"context"
	"time"

	"github.com/go-co-op/gocron"
	"github.com/jackc/pgx/v5/pgtype"
	"github.com/tgdrive/teldrive/internal/api"
	"github.com/tgdrive/teldrive/internal/config"
	"github.com/tgdrive/teldrive/internal/logging"
	"github.com/tgdrive/teldrive/internal/tgc"
	"github.com/tgdrive/teldrive/pkg/models"
	"go.uber.org/zap"
	"gorm.io/datatypes"
	"gorm.io/gorm"
)

type file struct {
	ID    string     `json:"id"`
	Parts []api.Part `json:"parts"`
}

type result struct {
	Files     datatypes.JSONSlice[file]
	ChannelId int64
	UserId    int64
	Session   string
}

type uploadResult struct {
	Parts     datatypes.JSONSlice[int]
	Session   string
	UserId    int64
	ChannelId int64
}

type CronService struct {
	db     *gorm.DB
	cnf    *config.ServerCmdConfig
	logger *zap.SugaredLogger
}

func StartCronJobs(ctx context.Context, scheduler *gocron.Scheduler, db *gorm.DB, cnf *config.ServerCmdConfig) {
	if !cnf.CronJobs.Enable {
		return
	}

	cron := CronService{db: db, cnf: cnf, logger: logging.DefaultLogger().Sugar()}

	scheduler.Every(cnf.CronJobs.CleanFilesInterval).Do(cron.cleanFiles, ctx)

	scheduler.Every(cnf.CronJobs.FolderSizeInterval).Do(cron.updateFolderSize)

	scheduler.Every(cnf.CronJobs.CleanUploadsInterval).Do(cron.cleanUploads, ctx)

	scheduler.StartAsync()
}

func (c *CronService) cleanFiles(ctx context.Context) {

	var results []result
	if err := c.db.Table("teldrive.files as f").
		Select("JSONB_AGG(jsonb_build_object('id', f.id, 'parts', f.parts)) as files,f.channel_id,f.user_id,s.session").
		Joins("LEFT JOIN teldrive.users as u ON u.user_id = f.user_id").
		Joins(`LEFT JOIN (
        SELECT user_id, session
        FROM teldrive.sessions
        WHERE created_at = (
            SELECT MAX(created_at)
            FROM teldrive.sessions s2
            WHERE s2.user_id = sessions.user_id
        )
    ) as s ON u.user_id = s.user_id`).
		Where("f.type = ?", "file").
		Where("f.status = ?", "pending_deletion").
		Group("f.channel_id").
		Group("f.user_id").
		Group("s.session").
		Scan(&results).Error; err != nil {
		return
	}

	middlewares := tgc.NewMiddleware(&c.cnf.TG, tgc.WithFloodWait(), tgc.WithRateLimit())

	for _, row := range results {

		if row.Session == "" {
			break
		}
		ids := []int{}

		fileIds := []string{}

		for _, file := range row.Files {
			fileIds = append(fileIds, file.ID)
			for _, part := range file.Parts {
				ids = append(ids, int(part.ID))
			}

		}

		client, _ := tgc.AuthClient(ctx, &c.cnf.TG, row.Session, middlewares...)
		err := tgc.DeleteMessages(ctx, client, row.ChannelId, ids)

		if err != nil {
			c.logger.Errorw("failed to delete messages", err)
			return
		}

		items := pgtype.Array[string]{
			Elements: fileIds,
			Valid:    true,
			Dims:     []pgtype.ArrayDimension{{Length: int32(len(fileIds)), LowerBound: 1}},
		}

		c.db.Where("id = any($1)", items).Delete(&models.File{})

		c.logger.Infow("cleaned files", "user", row.UserId, "channel", row.ChannelId)
	}
}

func (c *CronService) cleanUploads(ctx context.Context) {
	var results []uploadResult
	if err := c.db.Table("teldrive.uploads as up").
		Select("JSONB_AGG(up.part_id) as parts,up.channel_id,up.user_id,s.session").
		Joins("LEFT JOIN teldrive.users as u ON u.user_id = up.user_id").
		Joins(`LEFT JOIN (
        SELECT user_id, session
        FROM teldrive.sessions
        WHERE created_at = (
            SELECT MAX(created_at)
            FROM teldrive.sessions s2
            WHERE s2.user_id = sessions.user_id
        )
    ) as s ON u.user_id = s.user_id`).
		Where("up.created_at < ?", time.Now().UTC().Add(-c.cnf.TG.Uploads.Retention)).
		Group("up.channel_id").
		Group("up.user_id").
		Group("s.session").
		Scan(&results).Error; err != nil {
		return
	}

	middlewares := tgc.NewMiddleware(&c.cnf.TG, tgc.WithFloodWait(), tgc.WithRateLimit())
	for _, result := range results {

		if result.Session != "" && len(result.Parts) > 0 {
			client, _ := tgc.AuthClient(ctx, &c.cnf.TG, result.Session, middlewares...)

			err := tgc.DeleteMessages(ctx, client, result.ChannelId, result.Parts)
			if err != nil {
				c.logger.Errorw("failed to delete messages", err)
				return
			}
		}
		items := pgtype.Array[int]{
			Elements: result.Parts,
			Valid:    true,
			Dims:     []pgtype.ArrayDimension{{Length: int32(len(result.Parts)), LowerBound: 1}},
		}
		c.db.Where("part_id = any(?)", items).Where("channel_id = ?", result.ChannelId).
			Where("user_id = ?", result.UserId).Delete(&models.Upload{}).Delete(&models.Upload{})

	}
}

func (c *CronService) updateFolderSize() {
	c.db.Exec("call teldrive.update_size();")
}