package db

import (
	"context"
	"encoding/json"
	"time"

	"github.com/jackc/pgx/v5"
)

// Integration represents an ERP integration configuration.
type Integration struct {
	ID        string
	Name      string
	Enabled   bool
	Config    map[string]any
	CreatedAt time.Time
	UpdatedAt time.Time
}

// SyncLog represents a sync log entry.
type SyncLog struct {
	ID              string
	IntegrationID   string
	ItemID          *string
	Direction       string
	Status          string
	ExternalID      string
	ExternalModel   string
	RequestPayload  json.RawMessage
	ResponsePayload json.RawMessage
	ErrorMessage    string
	StartedAt       *time.Time
	CompletedAt     *time.Time
	CreatedAt       time.Time
}

// IntegrationRepository provides integration database operations.
type IntegrationRepository struct {
	db *DB
}

// NewIntegrationRepository creates a new integration repository.
func NewIntegrationRepository(db *DB) *IntegrationRepository {
	return &IntegrationRepository{db: db}
}

// GetByName returns an integration by name.
func (r *IntegrationRepository) GetByName(ctx context.Context, name string) (*Integration, error) {
	row := r.db.pool.QueryRow(ctx, `
		SELECT id, name, enabled, config, created_at, updated_at
		FROM integrations
		WHERE name = $1
	`, name)

	var i Integration
	var configJSON []byte
	err := row.Scan(&i.ID, &i.Name, &i.Enabled, &configJSON, &i.CreatedAt, &i.UpdatedAt)
	if err == pgx.ErrNoRows {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}

	if len(configJSON) > 0 {
		if err := json.Unmarshal(configJSON, &i.Config); err != nil {
			return nil, err
		}
	}

	return &i, nil
}

// Upsert creates or updates an integration by name.
func (r *IntegrationRepository) Upsert(ctx context.Context, name string, enabled bool, config map[string]any) error {
	configJSON, err := json.Marshal(config)
	if err != nil {
		return err
	}

	_, err = r.db.pool.Exec(ctx, `
		INSERT INTO integrations (name, enabled, config)
		VALUES ($1, $2, $3)
		ON CONFLICT (name) DO UPDATE SET
			enabled = EXCLUDED.enabled,
			config = EXCLUDED.config,
			updated_at = now()
	`, name, enabled, configJSON)
	return err
}

// CreateSyncLog inserts a new sync log entry.
func (r *IntegrationRepository) CreateSyncLog(ctx context.Context, entry *SyncLog) error {
	_, err := r.db.pool.Exec(ctx, `
		INSERT INTO sync_log (integration_id, item_id, direction, status, external_id, external_model, request_payload, response_payload, error_message, started_at, completed_at)
		VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11)
	`, entry.IntegrationID, entry.ItemID, entry.Direction, entry.Status,
		entry.ExternalID, entry.ExternalModel, entry.RequestPayload, entry.ResponsePayload,
		entry.ErrorMessage, entry.StartedAt, entry.CompletedAt)
	return err
}

// ListSyncLog returns recent sync log entries for an integration.
func (r *IntegrationRepository) ListSyncLog(ctx context.Context, integrationID string, limit int) ([]*SyncLog, error) {
	if limit <= 0 {
		limit = 50
	}

	rows, err := r.db.pool.Query(ctx, `
		SELECT id, integration_id, item_id, direction, status,
			external_id, external_model, request_payload, response_payload,
			error_message, started_at, completed_at, created_at
		FROM sync_log
		WHERE integration_id = $1
		ORDER BY created_at DESC
		LIMIT $2
	`, integrationID, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var logs []*SyncLog
	for rows.Next() {
		var l SyncLog
		err := rows.Scan(
			&l.ID, &l.IntegrationID, &l.ItemID, &l.Direction, &l.Status,
			&l.ExternalID, &l.ExternalModel, &l.RequestPayload, &l.ResponsePayload,
			&l.ErrorMessage, &l.StartedAt, &l.CompletedAt, &l.CreatedAt,
		)
		if err != nil {
			return nil, err
		}
		logs = append(logs, &l)
	}

	return logs, rows.Err()
}