package store

import (
	"context"
	"fmt"

	"git.kundeng.us/phoenix/textsender-models/tx0/message/scheduling"
	"github.com/google/uuid"
	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

type ScheduledMessageStore interface {
	Get(ctx context.Context, id uuid.UUID) (*scheduling.ScheduledMessage, error)
	FetchNextScheduledMessage(ctx context.Context) (*scheduling.ScheduledMessage, error)
	GetWithUserId(ctx context.Context, userId uuid.UUID) ([]*scheduling.ScheduledMessage, error)
	CreateScheduledMessage(ctx context.Context, schedMsg *scheduling.ScheduledMessage) error
	UpdateStatus(ctx context.Context, id uuid.UUID, updatedStatus string) (*string, error)
}

type PGScheduledMessageStore struct {
	db *pgxpool.Pool
}

func NewScheduledMessageStore(db *pgxpool.Pool) *PGScheduledMessageStore {
	return &PGScheduledMessageStore{db: db}
}

func (s *PGScheduledMessageStore) Get(ctx context.Context, id uuid.UUID) (*scheduling.ScheduledMessage, error) {
	query := `
		SELECT id, scheduled, created, status, user_id FROM scheduled_messages WHERE id = $1
	`

	var schMsg scheduling.ScheduledMessage
	err := s.db.QueryRow(ctx, query, id).Scan(
		&schMsg.Id, &schMsg.Scheduled, &schMsg.Created, &schMsg.Status, &schMsg.UserId,
	)

	if err == pgx.ErrNoRows {
		return nil, fmt.Errorf("No rows")
	} else if err != nil {
		return nil, fmt.Errorf("Getting scheduled message: %w", err)
	}

	return &schMsg, nil
}

func (s *PGScheduledMessageStore) FetchNextScheduledMessage(ctx context.Context) (*scheduling.ScheduledMessage, error) {
	query := `
		UPDATE scheduled_messages
		SET status = $1
		WHERE id = (
			SELECT id FROM scheduled_messages
			WHERE status = $2
			ORDER BY id
			FOR UPDATE SKIP LOCKED
			LIMIT 1
		)
		RETURNING id, scheduled, created, status, user_id
	`
	var schMsg scheduling.ScheduledMessage
	err := s.db.QueryRow(ctx, query, scheduling.Processing, scheduling.Ready).Scan(
		&schMsg.Id, &schMsg.Scheduled, &schMsg.Created, &schMsg.Status, &schMsg.UserId,
	)

	if err == pgx.ErrNoRows {
		return nil, nil
	} else if err != nil {
		return nil, fmt.Errorf("Getting scheduled message: %w", err)
	} else {
		return &schMsg, nil
	}
}

func (s *PGScheduledMessageStore) GetWithUserId(ctx context.Context, userId uuid.UUID) ([]*scheduling.ScheduledMessage, error) {
	query := `
		SELECT id, scheduled, created, status, user_id FROM scheduled_messages WHERE user_id = $1
	`
	rows, err := s.db.Query(ctx, query, userId)
	if err != nil {
		return nil, fmt.Errorf("Error retrieving rows from scheduled_messages: %w", err)
	}

	var schMsgs []*scheduling.ScheduledMessage

	for rows.Next() {
		var schMsg scheduling.ScheduledMessage
		if err := rows.Scan(&schMsg.Id, &schMsg.Scheduled, &schMsg.Created, &schMsg.Status, &schMsg.UserId); err != nil {
			return nil, fmt.Errorf("Error fetching data from row: %w", err)
		} else {
			schMsgs = append(schMsgs, &schMsg)
		}
	}

	if err := rows.Err(); err != nil {
		return nil, err
	} else {
		return schMsgs, nil
	}
}

func (s *PGScheduledMessageStore) CreateScheduledMessage(ctx context.Context, schedMsg *scheduling.ScheduledMessage) error {
	query := `
		INSERT INTO scheduled_messages (scheduled, status, user_id)
		VALUES ($1, $2, $3)
		RETURNING id, created
	`

	return s.db.QueryRow(ctx, query, schedMsg.Scheduled, schedMsg.Status, schedMsg.UserId).Scan(
		&schedMsg.Id, &schedMsg.Created,
	)
}

func (s *PGScheduledMessageStore) UpdateStatus(ctx context.Context, id uuid.UUID, updatedStatus string) (*string, error) {
	query := `
		UPDATE scheduled_messages set status = $1 WHERE id = $2
		RETURNING status
	`

	var returnedStatus string

	if err := s.db.QueryRow(ctx, query, updatedStatus, id).Scan(&returnedStatus); err != nil {
		return nil, err
	} else {
		return &returnedStatus, nil
	}
}