package processor

import (
	"context"
	"fmt"
	"strings"

	"apskel-pos-be/internal/constants"
	"apskel-pos-be/internal/models"

	"github.com/google/uuid"
)

// Teams are the parent product categories, plus Pusat for spending that belongs to
// no single team. Both purchase orders and cash advances are charged to one, so the rules
// for picking and storing a team live here rather than in either processor.

// listTeams returns the teams money can be charged to: the parent categories of the
// outlet in scope, followed by Pusat. Pusat has no category row, so it is appended
// here rather than read from the database.
func listTeams(ctx context.Context, categoryRepo CategoryRepository, organizationID uuid.UUID, outletID *uuid.UUID) (*models.ListPurchaseTeamsResponse, error) {
	categories, err := categoryRepo.ListParentCategories(ctx, organizationID, outletID)
	if err != nil {
		return nil, fmt.Errorf("failed to list parent categories: %w", err)
	}

	teams := make([]models.PurchaseTeam, 0, len(categories)+1)
	for _, category := range categories {
		categoryID := category.ID
		teams = append(teams, models.PurchaseTeam{
			Scope:      constants.PurchaseTeamScopeCategory,
			CategoryID: &categoryID,
			Name:       category.Name,
		})
	}

	teams = append(teams, models.PurchaseTeam{
		Scope: constants.PurchaseTeamScopeCentral,
		Name:  constants.PurchaseTeamCentralName,
	})

	return &models.ListPurchaseTeamsResponse{Teams: teams}, nil
}

// resolveTeamSelection turns a requested team into the scope/category pair that gets
// stored, mirroring the database check constraint. A nil or empty scope means no
// team, which is deliberately different from Pusat — callers that require a team
// reject that case before getting here. Which outlet's Pusat it is comes from the
// record's own outlet, so 'central' needs nothing stored beyond the scope itself.
func resolveTeamSelection(ctx context.Context, categoryRepo CategoryRepository, organizationID uuid.UUID, outletID *uuid.UUID, scope *string, categoryID *uuid.UUID) (*string, *uuid.UUID, error) {
	if scope == nil {
		return nil, nil, nil
	}

	switch strings.TrimSpace(*scope) {
	case "":
		return nil, nil, nil

	case constants.PurchaseTeamScopeCentral:
		resolved := constants.PurchaseTeamScopeCentral
		return &resolved, nil, nil

	case constants.PurchaseTeamScopeCategory:
		if categoryID == nil {
			return nil, nil, fmt.Errorf("team_category_id is required when team_scope is category")
		}

		category, err := categoryRepo.GetByID(ctx, *categoryID)
		if err != nil {
			return nil, nil, fmt.Errorf("team category not found: %w", err)
		}
		if category.OrganizationID != organizationID {
			return nil, nil, fmt.Errorf("team category does not belong to this organization")
		}
		if category.ParentID != nil {
			return nil, nil, fmt.Errorf("team must be a parent category")
		}
		// Categories without an outlet are shared, so only an outlet-specific
		// category has to match the outlet the record is booked against.
		if category.OutletID != nil && outletID != nil && *category.OutletID != *outletID {
			return nil, nil, fmt.Errorf("team category belongs to a different outlet")
		}

		resolved := constants.PurchaseTeamScopeCategory
		return &resolved, &category.ID, nil
	}

	return nil, nil, fmt.Errorf("team_scope must be one of: category, central")
}