/*
Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
Copyright (C) ITsysCOM GmbH

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>
*/

package utils

import (
	"maps"
	"strconv"
	"strings"
)

// RoutesDefaultRatio is the default ratio value for routes when none is
// explicitly specified in the profile. Defined here to avoid circular
// dependencies with the config package.
var RoutesDefaultRatio = 1

// RouteProfile represents the configuration of a Route profile.
type RouteProfile struct {
	Tenant            string
	ID                string // LCR Profile ID
	FilterIDs         []string
	Weights           DynamicWeights
	Blockers          DynamicBlockers
	Sorting           string // Sorting strategy
	SortingParameters []string
	Routes            []*Route
}

// Clone method for RouteProfile
func (rp *RouteProfile) Clone() *RouteProfile {
	if rp == nil {
		return nil
	}
	clone := &RouteProfile{
		Tenant:  rp.Tenant,
		ID:      rp.ID,
		Sorting: rp.Sorting,
	}
	if rp.FilterIDs != nil {
		clone.FilterIDs = make([]string, len(rp.FilterIDs))
		copy(clone.FilterIDs, rp.FilterIDs)
	}
	if rp.SortingParameters != nil {
		clone.SortingParameters = make([]string, len(rp.SortingParameters))
		copy(clone.SortingParameters, rp.SortingParameters)
	}
	if rp.Routes != nil {
		clone.Routes = make([]*Route, len(rp.Routes))
		for i, route := range rp.Routes {
			clone.Routes[i] = route.Clone()
		}
	}
	if rp.Weights != nil {
		clone.Weights = rp.Weights.Clone()
	}
	if rp.Blockers != nil {
		clone.Blockers = rp.Blockers.Clone()
	}
	return clone
}

// CacheClone returns a clone of RouteProfile used by ltcache CacheCloner
func (rp *RouteProfile) CacheClone() any {
	return rp.Clone()
}

// RouteProfileWithAPIOpts wraps RouteProfile with APIOpts.
type RouteProfileWithAPIOpts struct {
	*RouteProfile
	APIOpts map[string]any
}

// compileCacheParameters prepares route ratios for MetaLoad sorting by parsing the
// SortingParameters and applying appropriate ratio values to each route.
func (rp *RouteProfile) compileCacheParameters() error {
	if rp.Sorting != MetaLoad {
		return nil
	}

	// Parse route ID to ratio mappings.
	ratioMap := make(map[string]int)
	for _, param := range rp.SortingParameters {
		parts := strings.Split(param, ConcatenatedKeySep)
		ratio, err := strconv.Atoi(parts[1])
		if err != nil {
			return err
		}
		ratioMap[parts[0]] = ratio
	}

	// Get default ratio (from map or config).
	defaultRatio := RoutesDefaultRatio
	if mapDefault, exists := ratioMap[MetaDefault]; exists {
		defaultRatio = mapDefault
	}

	// Apply appropriate ratio to each route.
	for _, route := range rp.Routes {
		route.cacheRoute = make(map[string]any)
		ratio, exists := ratioMap[route.ID]
		if !exists {
			ratio = defaultRatio
		}
		route.cacheRoute[MetaRatio] = ratio
	}

	return nil
}

// Compile is a wrapper for convenience setting up the RouteProfile.
func (rp *RouteProfile) Compile() error {
	return rp.compileCacheParameters()
}

// TenantID returns unique identifier of the LCRProfile in a multi-tenant environment.
func (rp *RouteProfile) TenantID() string {
	return ConcatenatedKey(rp.Tenant, rp.ID)
}

// Set implements the profile interface, setting values in RouteProfile based on path.
func (rp *RouteProfile) Set(path []string, val any, newBranch bool) (err error) {
	switch len(path) {
	default:
		return ErrWrongPath
	case 1:
		switch path[0] {
		default:
			return ErrWrongPath
		case Tenant:
			rp.Tenant = IfaceAsString(val)
		case ID:
			rp.ID = IfaceAsString(val)
		case FilterIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rp.FilterIDs = append(rp.FilterIDs, valA...)
		case SortingParameters:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rp.SortingParameters = append(rp.SortingParameters, valA...)
		case Sorting:
			if valStr := IfaceAsString(val); len(valStr) != 0 {
				rp.Sorting = valStr
			}
		case Weights:
			if val != EmptyString {
				rp.Weights, err = NewDynamicWeightsFromString(IfaceAsString(val), InfieldSep, ANDSep)
			}
		case Blockers:
			if val != EmptyString {
				rp.Blockers, err = NewDynamicBlockersFromString(IfaceAsString(val), InfieldSep, ANDSep)
			}
		}
	case 2:
		if val == EmptyString {
			return
		}
		if path[0] != Routes {
			return ErrWrongPath
		}
		if len(rp.Routes) == 0 || newBranch {
			rp.Routes = append(rp.Routes, new(Route))
		}
		rt := rp.Routes[len(rp.Routes)-1]
		switch path[1] {
		case ID:
			rt.ID = IfaceAsString(val)
		case FilterIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rt.FilterIDs = append(rt.FilterIDs, valA...)
		case AccountIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rt.AccountIDs = append(rt.AccountIDs, valA...)
		case RateProfileIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rt.RateProfileIDs = append(rt.RateProfileIDs, valA...)
		case ResourceIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rt.ResourceIDs = append(rt.ResourceIDs, valA...)
		case StatIDs:
			var valA []string
			valA, err = IfaceAsStringSlice(val)
			rt.StatIDs = append(rt.StatIDs, valA...)
		case Weights:
			if val != EmptyString {
				rt.Weights, err = NewDynamicWeightsFromString(IfaceAsString(val), InfieldSep, ANDSep)
			}
		case Blockers:
			if val != EmptyString {
				rt.Blockers, err = NewDynamicBlockersFromString(IfaceAsString(val), InfieldSep, ANDSep)
			}
		case RouteParameters:
			rt.RouteParameters = IfaceAsString(val)
		default:
			return ErrWrongPath
		}
	}
	return
}

// Merge implements the profile interface, merging values from another RouteProfile.
func (rp *RouteProfile) Merge(v2 any) {
	vi := v2.(*RouteProfile)
	if len(vi.Tenant) != 0 {
		rp.Tenant = vi.Tenant
	}
	if len(vi.ID) != 0 {
		rp.ID = vi.ID
	}
	rp.FilterIDs = append(rp.FilterIDs, vi.FilterIDs...)
	rp.SortingParameters = append(rp.SortingParameters, vi.SortingParameters...)
	var equal bool
	for _, routeV2 := range vi.Routes {
		for _, route := range rp.Routes {
			if route.ID == routeV2.ID {
				route.Merge(routeV2)
				equal = true
				break
			}
		}
		if !equal {
			rp.Routes = append(rp.Routes, routeV2)
		}
		equal = false
	}
	rp.Weights = append(rp.Weights, vi.Weights...)
	rp.Blockers = append(rp.Blockers, vi.Blockers...)
	if len(vi.Sorting) != 0 {
		rp.Sorting = vi.Sorting
	}
}

// String implements the DataProvider interface, returning the RouteProfile in JSON format.
func (rp *RouteProfile) String() string { return ToJSON(rp) }

// FieldAsString implements the DataProvider interface, retrieving field value as string.
func (rp *RouteProfile) FieldAsString(fldPath []string) (_ string, err error) {
	var val any
	if val, err = rp.FieldAsInterface(fldPath); err != nil {
		return
	}
	return IfaceAsString(val), nil
}

// FieldAsInterface implements the DataProvider interface, retrieving field value as interface.
func (rp *RouteProfile) FieldAsInterface(fldPath []string) (_ any, err error) {
	if len(fldPath) == 1 {
		switch fldPath[0] {
		default:
			fld, idx := GetPathIndex(fldPath[0])
			if idx != nil {
				switch fld {
				case SortingParameters:
					if *idx < len(rp.SortingParameters) {
						return rp.SortingParameters[*idx], nil
					}
				case FilterIDs:
					if *idx < len(rp.FilterIDs) {
						return rp.FilterIDs[*idx], nil
					}
				case Routes:
					if *idx < len(rp.Routes) {
						return rp.Routes[*idx], nil
					}
				}
			}
			return nil, ErrNotFound
		case Tenant:
			return rp.Tenant, nil
		case ID:
			return rp.ID, nil
		case FilterIDs:
			return rp.FilterIDs, nil
		case Weights:
			return rp.Weights.String(InfieldSep, ANDSep), nil
		case SortingParameters:
			return rp.SortingParameters, nil
		case Sorting:
			return rp.Sorting, nil
		case Blockers:
			return rp.Blockers.String(InfieldSep, ANDSep), nil
		case Routes:
			return rp.Routes, nil
		}
	}
	if len(fldPath) == 0 {
		return nil, ErrNotFound
	}
	fld, idx := GetPathIndex(fldPath[0])
	if fld != Routes ||
		idx == nil {
		return nil, ErrNotFound
	}
	if *idx >= len(rp.Routes) {
		return nil, ErrNotFound
	}
	return rp.Routes[*idx].FieldAsInterface(fldPath[1:])
}

// Route defines a single route within a RouteProfile.
type Route struct {
	ID              string // RouteID
	FilterIDs       []string
	AccountIDs      []string
	RateProfileIDs  []string // used when computing price
	ResourceIDs     []string // queried in some strategies
	StatIDs         []string // queried in some strategies
	Weights         DynamicWeights
	Blockers        DynamicBlockers // if true, stops processing further routes
	RouteParameters string

	// Internal cache for route properties
	// Example: cacheRoute["*ratio"] contains the route's ratio value
	cacheRoute map[string]any
}

// Clone method for Route
func (r *Route) Clone() *Route {
	if r == nil {
		return nil
	}
	clone := &Route{
		ID:              r.ID,
		RouteParameters: r.RouteParameters,
	}
	if r.FilterIDs != nil {
		clone.FilterIDs = make([]string, len(r.FilterIDs))
		copy(clone.FilterIDs, r.FilterIDs)
	}
	if r.Weights != nil {
		clone.Weights = r.Weights.Clone()
	}
	if r.Blockers != nil {
		clone.Blockers = r.Blockers.Clone()
	}
	if r.AccountIDs != nil {
		clone.AccountIDs = make([]string, len(r.AccountIDs))
		copy(clone.AccountIDs, r.AccountIDs)
	}
	if r.RateProfileIDs != nil {
		clone.RateProfileIDs = make([]string, len(r.RateProfileIDs))
		copy(clone.RateProfileIDs, r.RateProfileIDs)
	}
	if r.ResourceIDs != nil {
		clone.ResourceIDs = make([]string, len(r.ResourceIDs))
		copy(clone.ResourceIDs, r.ResourceIDs)
	}
	if r.StatIDs != nil {
		clone.StatIDs = make([]string, len(r.StatIDs))
		copy(clone.StatIDs, r.StatIDs)
	}
	if r.cacheRoute != nil {
		clone.cacheRoute = make(map[string]any)
		maps.Copy(clone.cacheRoute, r.cacheRoute)
	}
	return clone
}

// Ratio returns the cached ratio value for this route.
func (r *Route) Ratio() any {
	return r.cacheRoute[MetaRatio]
}

// Merge implements the merge interface, merging values from another Route.
func (r *Route) Merge(v2 *Route) {
	if len(v2.ID) != 0 {
		r.ID = v2.ID
	}
	if len(v2.RouteParameters) != 0 {
		r.RouteParameters = v2.RouteParameters
	}
	r.Weights = append(r.Weights, v2.Weights...)
	r.Blockers = append(r.Blockers, v2.Blockers...)
	r.FilterIDs = append(r.FilterIDs, v2.FilterIDs...)
	r.AccountIDs = append(r.AccountIDs, v2.AccountIDs...)
	r.RateProfileIDs = append(r.RateProfileIDs, v2.RateProfileIDs...)
	r.ResourceIDs = append(r.ResourceIDs, v2.ResourceIDs...)
	r.StatIDs = append(r.StatIDs, v2.StatIDs...)
}

// String implements the DataProvider interface, returning the Route in JSON format.
func (r *Route) String() string { return ToJSON(r) }

// FieldAsString implements the DataProvider interface, retrieving field value as string.
func (r *Route) FieldAsString(fldPath []string) (_ string, err error) {
	var val any
	if val, err = r.FieldAsInterface(fldPath); err != nil {
		return
	}
	return IfaceAsString(val), nil
}

// FieldAsInterface implements the DataProvider interface, retrieving field value as interface.
func (r *Route) FieldAsInterface(fldPath []string) (_ any, err error) {
	if len(fldPath) != 1 {
		return nil, ErrNotFound
	}
	switch fldPath[0] {
	default:
		fld, idx := GetPathIndex(fldPath[0])
		if idx != nil {
			switch fld {
			case AccountIDs:
				if *idx < len(r.AccountIDs) {
					return r.AccountIDs[*idx], nil
				}
			case FilterIDs:
				if *idx < len(r.FilterIDs) {
					return r.FilterIDs[*idx], nil
				}
			case RateProfileIDs:
				if *idx < len(r.RateProfileIDs) {
					return r.RateProfileIDs[*idx], nil
				}
			case ResourceIDs:
				if *idx < len(r.ResourceIDs) {
					return r.ResourceIDs[*idx], nil
				}
			case StatIDs:
				if *idx < len(r.StatIDs) {
					return r.StatIDs[*idx], nil
				}
			}
		}
		return nil, ErrNotFound
	case ID:
		return r.ID, nil
	case FilterIDs:
		return r.FilterIDs, nil
	case AccountIDs:
		return r.AccountIDs, nil
	case RateProfileIDs:
		return r.RateProfileIDs, nil
	case ResourceIDs:
		return r.ResourceIDs, nil
	case StatIDs:
		return r.StatIDs, nil
	case Weights:
		return r.Weights.String(InfieldSep, ANDSep), nil
	case Blockers:
		return r.Blockers.String(InfieldSep, ANDSep), nil
	case RouteParameters:
		return r.RouteParameters, nil
	}
}