package schedule

import (
	"context"
	"errors"
	"fmt"
	"time"

	"tm/pkg/logger"
	"tm/pkg/mongo"

	"go.mongodb.org/mongo-driver/v2/bson"
	mongodriver "go.mongodb.org/mongo-driver/v2/mongo"
	"go.mongodb.org/mongo-driver/v2/mongo/options"
)

const (
	dailyJobRunsCollection = "daily_job_runs"
	DailyJobStatusCompleted = "completed"

	TEDScraperJobName      = "ted_scraper"
	AIPipelineDailyJobName = "ai_pipeline_daily"
)

type dailyJobRun struct {
	ID          string `bson:"_id"`
	JobName     string `bson:"job_name"`
	Date        string `bson:"date"`
	CompletedAt int64  `bson:"completed_at"`
	Status      string `bson:"status"`
}

// DailyJobTracker records successful daily job runs so startup catch-up can skip
// dates that were already completed before a server restart.
type DailyJobTracker struct {
	mongo  *mongo.ConnectionManager
	logger logger.Logger
}

func NewDailyJobTracker(mongoManager *mongo.ConnectionManager, log logger.Logger) *DailyJobTracker {
	return &DailyJobTracker{
		mongo:  mongoManager,
		logger: log,
	}
}

func dailyJobRunID(jobName string, date time.Time) string {
	return fmt.Sprintf("%s:%s", jobName, date.Format("2006-01-02"))
}

// IsCompleted reports whether jobName finished successfully for the given local calendar date.
func (t *DailyJobTracker) IsCompleted(ctx context.Context, jobName string, date time.Time) (bool, error) {
	if jobName == "" {
		return false, fmt.Errorf("daily job tracker: job name is required")
	}

	var doc dailyJobRun
	err := t.mongo.GetCollection(dailyJobRunsCollection).FindOne(
		ctx,
		bson.M{"_id": dailyJobRunID(jobName, date), "status": DailyJobStatusCompleted},
	).Decode(&doc)
	if err != nil {
		if errors.Is(err, mongodriver.ErrNoDocuments) {
			return false, nil
		}
		return false, fmt.Errorf("daily job tracker: check completed %q: %w", jobName, err)
	}

	return true, nil
}

// MarkCompleted records a successful daily job run for the given local calendar date.
func (t *DailyJobTracker) MarkCompleted(ctx context.Context, jobName string, date time.Time) error {
	if jobName == "" {
		return fmt.Errorf("daily job tracker: job name is required")
	}

	dateKey := date.Format("2006-01-02")
	now := time.Now().Unix()

	_, err := t.mongo.GetCollection(dailyJobRunsCollection).UpdateOne(
		ctx,
		bson.M{"_id": dailyJobRunID(jobName, date)},
		bson.M{
			"$set": bson.M{
				"job_name":     jobName,
				"date":         dateKey,
				"completed_at": now,
				"status":       DailyJobStatusCompleted,
			},
			"$setOnInsert": bson.M{"_id": dailyJobRunID(jobName, date)},
		},
		options.UpdateOne().SetUpsert(true),
	)
	if err != nil {
		return fmt.Errorf("daily job tracker: mark completed %q on %s: %w", jobName, dateKey, err)
	}

	t.logger.Debug("Daily job marked completed", map[string]interface{}{
		"job_name":     jobName,
		"date":         dateKey,
		"completed_at": now,
	})

	return nil
}