package models

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"git.eeqj.de/sneak/upaas/internal/database"
)

// WebhookEvent represents a received webhook event.
type WebhookEvent struct {
	db *database.Database

	ID        int64
	AppID     string
	EventType string
	Branch    string
	CommitSHA sql.NullString
	Payload   sql.NullString
	Matched   bool
	Processed bool
	CreatedAt time.Time
}

// NewWebhookEvent creates a new WebhookEvent with a database reference.
func NewWebhookEvent(db *database.Database) *WebhookEvent {
	return &WebhookEvent{db: db}
}

// Save inserts or updates the webhook event in the database.
func (w *WebhookEvent) Save(ctx context.Context) error {
	if w.ID == 0 {
		return w.insert(ctx)
	}

	return w.update(ctx)
}

// Reload refreshes the webhook event from the database.
func (w *WebhookEvent) Reload(ctx context.Context) error {
	query := `
		SELECT id, app_id, event_type, branch, commit_sha, payload,
			matched, processed, created_at
		FROM webhook_events WHERE id = ?`

	row := w.db.QueryRow(ctx, query, w.ID)

	return w.scan(row)
}

func (w *WebhookEvent) insert(ctx context.Context) error {
	query := `
		INSERT INTO webhook_events (
			app_id, event_type, branch, commit_sha, payload, matched, processed
		) VALUES (?, ?, ?, ?, ?, ?, ?)`

	result, err := w.db.Exec(ctx, query,
		w.AppID, w.EventType, w.Branch, w.CommitSHA,
		w.Payload, w.Matched, w.Processed,
	)
	if err != nil {
		return err
	}

	id, err := result.LastInsertId()
	if err != nil {
		return err
	}

	w.ID = id

	return w.Reload(ctx)
}

func (w *WebhookEvent) update(ctx context.Context) error {
	query := "UPDATE webhook_events SET processed = ? WHERE id = ?"

	_, err := w.db.Exec(ctx, query, w.Processed, w.ID)

	return err
}

func (w *WebhookEvent) scan(row *sql.Row) error {
	return row.Scan(
		&w.ID, &w.AppID, &w.EventType, &w.Branch, &w.CommitSHA,
		&w.Payload, &w.Matched, &w.Processed, &w.CreatedAt,
	)
}

// FindWebhookEvent finds a webhook event by ID.
//
//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
func FindWebhookEvent(
	ctx context.Context,
	db *database.Database,
	id int64,
) (*WebhookEvent, error) {
	event := NewWebhookEvent(db)
	event.ID = id

	row := db.QueryRow(ctx, `
		SELECT id, app_id, event_type, branch, commit_sha, payload,
			matched, processed, created_at
		FROM webhook_events WHERE id = ?`,
		id,
	)

	err := event.scan(row)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, nil
		}

		return nil, fmt.Errorf("scanning webhook event: %w", err)
	}

	return event, nil
}

// FindWebhookEventsByAppID finds recent webhook events for an app.
func FindWebhookEventsByAppID(
	ctx context.Context,
	db *database.Database,
	appID string,
	limit int,
) ([]*WebhookEvent, error) {
	query := `
		SELECT id, app_id, event_type, branch, commit_sha, payload,
			matched, processed, created_at
		FROM webhook_events WHERE app_id = ? ORDER BY created_at DESC LIMIT ?`

	rows, err := db.Query(ctx, query, appID, limit)
	if err != nil {
		return nil, fmt.Errorf("querying webhook events by app: %w", err)
	}

	defer func() { _ = rows.Close() }()

	var events []*WebhookEvent

	for rows.Next() {
		event := NewWebhookEvent(db)

		scanErr := rows.Scan(
			&event.ID, &event.AppID, &event.EventType, &event.Branch,
			&event.CommitSHA, &event.Payload, &event.Matched,
			&event.Processed, &event.CreatedAt,
		)
		if scanErr != nil {
			return nil, scanErr
		}

		events = append(events, event)
	}

	return events, rows.Err()
}

// FindUnprocessedWebhookEvents finds unprocessed matched webhook events.
func FindUnprocessedWebhookEvents(
	ctx context.Context,
	db *database.Database,
) ([]*WebhookEvent, error) {
	query := `
		SELECT id, app_id, event_type, branch, commit_sha, payload,
			matched, processed, created_at
		FROM webhook_events
		WHERE matched = 1 AND processed = 0 ORDER BY created_at ASC`

	rows, err := db.Query(ctx, query)
	if err != nil {
		return nil, fmt.Errorf("querying unprocessed webhook events: %w", err)
	}

	defer func() { _ = rows.Close() }()

	var events []*WebhookEvent

	for rows.Next() {
		event := NewWebhookEvent(db)

		scanErr := rows.Scan(
			&event.ID, &event.AppID, &event.EventType, &event.Branch,
			&event.CommitSHA, &event.Payload, &event.Matched,
			&event.Processed, &event.CreatedAt,
		)
		if scanErr != nil {
			return nil, scanErr
		}

		events = append(events, event)
	}

	return events, rows.Err()
}