package store

import (
	"context"
	"errors"
	"strings"

	"github.com/tech/sendico/payments/storage"
	"github.com/tech/sendico/payments/storage/model"
	"github.com/tech/sendico/pkg/db/repository"
	ri "github.com/tech/sendico/pkg/db/repository/index"
	"github.com/tech/sendico/pkg/merrors"
	"github.com/tech/sendico/pkg/mlogger"
	"go.mongodb.org/mongo-driver/v2/bson"
	"go.mongodb.org/mongo-driver/v2/mongo"
	"go.uber.org/zap"
)

type PlanTemplates struct {
	logger mlogger.Logger
	repo   repository.Repository
}

// NewPlanTemplates constructs a Mongo-backed plan template store.
func NewPlanTemplates(logger mlogger.Logger, repo repository.Repository) (*PlanTemplates, error) {
	if repo == nil {
		return nil, merrors.InvalidArgument("planTemplatesStore: repository is nil")
	}

	indexes := []*ri.Definition{
		{
			Keys: []ri.Key{
				{Field: "fromRail", Sort: ri.Asc},
				{Field: "toRail", Sort: ri.Asc},
				{Field: "network", Sort: ri.Asc},
			},
			Unique: true,
		},
		{
			Keys: []ri.Key{{Field: "fromRail", Sort: ri.Asc}},
		},
		{
			Keys: []ri.Key{{Field: "toRail", Sort: ri.Asc}},
		},
		{
			Keys: []ri.Key{{Field: "isEnabled", Sort: ri.Asc}},
		},
	}

	for _, def := range indexes {
		if err := repo.CreateIndex(def); err != nil {
			logger.Error("Failed to ensure plan templates index", zap.Error(err), zap.String("collection", repo.Collection()))
			return nil, err
		}
	}

	return &PlanTemplates{
		logger: logger.Named("plan_templates"),
		repo:   repo,
	}, nil
}

func (p *PlanTemplates) Create(ctx context.Context, template *model.PaymentPlanTemplate) error {
	if template == nil {
		return merrors.InvalidArgument("planTemplatesStore: nil template")
	}
	template.Normalize()
	if template.FromRail == "" || template.FromRail == model.RailUnspecified {
		return merrors.InvalidArgument("planTemplatesStore: from_rail is required")
	}
	if template.ToRail == "" || template.ToRail == model.RailUnspecified {
		return merrors.InvalidArgument("planTemplatesStore: to_rail is required")
	}
	if len(template.Steps) == 0 {
		return merrors.InvalidArgument("planTemplatesStore: steps are required")
	}
	if template.ID.IsZero() {
		template.SetID(bson.NewObjectID())
	} else {
		template.Update()
	}

	filter := repository.Filter("fromRail", template.FromRail).And(
		repository.Filter("toRail", template.ToRail),
		repository.Filter("network", template.Network),
	)

	if err := p.repo.Insert(ctx, template, filter); err != nil {
		if errors.Is(err, merrors.ErrDataConflict) {
			return storage.ErrDuplicatePlanTemplate
		}
		return err
	}
	return nil
}

func (p *PlanTemplates) Update(ctx context.Context, template *model.PaymentPlanTemplate) error {
	if template == nil {
		return merrors.InvalidArgument("planTemplatesStore: nil template")
	}
	if template.ID.IsZero() {
		return merrors.InvalidArgument("planTemplatesStore: missing template id")
	}
	template.Normalize()
	template.Update()
	if err := p.repo.Update(ctx, template); err != nil {
		if errors.Is(err, merrors.ErrNoData) {
			return storage.ErrPlanTemplateNotFound
		}
		return err
	}
	return nil
}

func (p *PlanTemplates) GetByID(ctx context.Context, id bson.ObjectID) (*model.PaymentPlanTemplate, error) {
	if id == bson.NilObjectID {
		return nil, merrors.InvalidArgument("planTemplatesStore: template id is required")
	}
	entity := &model.PaymentPlanTemplate{}
	if err := p.repo.Get(ctx, id, entity); err != nil {
		if errors.Is(err, merrors.ErrNoData) {
			return nil, storage.ErrPlanTemplateNotFound
		}
		return nil, err
	}
	entity.Normalize()
	return entity, nil
}

func (p *PlanTemplates) List(ctx context.Context, filter *model.PaymentPlanTemplateFilter) (*model.PaymentPlanTemplateList, error) {
	if filter == nil {
		filter = &model.PaymentPlanTemplateFilter{}
	}

	query := repository.Query()

	if from := normalizedRailFilterValues(filter.FromRail); len(from) == 1 {
		query = query.Filter(repository.Field("fromRail"), from[0])
	} else if len(from) > 1 {
		query = query.In(repository.Field("fromRail"), stringSliceToAny(from)...)
	}
	if to := normalizedRailFilterValues(filter.ToRail); len(to) == 1 {
		query = query.Filter(repository.Field("toRail"), to[0])
	} else if len(to) > 1 {
		query = query.In(repository.Field("toRail"), stringSliceToAny(to)...)
	}
	if network := strings.ToUpper(strings.TrimSpace(filter.Network)); network != "" {
		query = query.Filter(repository.Field("network"), network)
	}
	if filter.IsEnabled != nil {
		query = query.Filter(repository.Field("isEnabled"), *filter.IsEnabled)
	}

	templates := make([]*model.PaymentPlanTemplate, 0)
	decoder := func(cur *mongo.Cursor) error {
		item := &model.PaymentPlanTemplate{}
		if err := cur.Decode(item); err != nil {
			return err
		}
		item.Normalize()
		templates = append(templates, item)
		return nil
	}

	if err := p.repo.FindManyByFilter(ctx, query, decoder); err != nil && !errors.Is(err, merrors.ErrNoData) {
		return nil, err
	}

	return &model.PaymentPlanTemplateList{
		Items: templates,
	}, nil
}

var _ storage.PlanTemplatesStore = (*PlanTemplates)(nil)