ParamList.go

package docxplate

import (
	"encoding/json"
	"log"
	"reflect"
	"regexp"
	"strings"
)

// ParamList ..
type ParamList []*Param

// Get method returns the value associated with the given name
func (params ParamList) Get(key string) any {
	for _, p := range params {
		if p.Key == key {
			return p.Value
		}
	}
	return nil
}

// Len ..
func (params ParamList) Len() int {
	return len(params)
}

// AnyToParams - load params from given any struct
// 1) Convert struct to JSON
// 2) Now convert JSON to map[string]any
// 3) Clear params from nil
func AnyToParams(v any) ParamList {
	// to JSON output
	buf, _ := json.MarshalIndent(v, "", "\t")
	return JSONToParams(buf)
}

// JSONToParams - load params from JSON
func JSONToParams(buf []byte) ParamList {
	// to map
	m := map[string]any{}
	if err := json.Unmarshal(buf, &m); err != nil {
		log.Printf("JSONToParams: %s", err)
		return nil
	}
	// to filtered/clean map
	params := mapToParams(m)
	params.Walk(func(p *Param) {
		// use Walk func built-in logic to assign keys
	})

	return params
}

// walk map[string]any and collect valid params
func mapToParams(m map[string]any) ParamList {
	var params ParamList
	for mKey, mVal := range m {
		p := NewParam(mKey)

		switch v := mVal.(type) {
		case map[string]any:
			p.Type = StructParam
			p.Params = mapToParams(v)
		case []any:
			p.Type = SliceParam
			p.Params = sliceToParams(v)
		case *Image:
			imgVal, err := processImage(v)
			if err != nil {
				log.Printf("ProcessImage: %s", err)
				continue
			}
			p.Type = ImageParam
			p.SetValue(imgVal)
		default:
			p.Type = StringParam
			p.SetValue(mVal)
		}

		if mVal == nil && p.Params == nil {
			continue
		}
		params = append(params, p)

	}

	return params
}

// sliceToParams - slice of unknown - simple slice or complex
func sliceToParams(arr []any) ParamList {
	var params ParamList

	for i, val := range arr {
		// Use index +1 because in template for user not useful see
		// 0 as start number. Only programmers will understand
		p := NewParam(i + 1)

		switch v := val.(type) {
		case map[string]any:
			p.Type = StructParam
			p.Params = mapToParams(v)
		default:
			p.Type = StringParam
			p.SetValue(v)
		}

		if val == nil && p.Params == nil {
			continue
		}
		params = append(params, p)
	}

	return params
}

// StructToParams - walk struct and collect valid params
func StructToParams(paramStruct any) ParamList {
	var params ParamList
	var keys reflect.Type
	var vals reflect.Value
	var ok bool

	if vals, ok = paramStruct.(reflect.Value); !ok {
		vals = reflect.ValueOf(paramStruct)
	}
	keys = vals.Type()

	keynum := keys.NumField()
	for i := 0; i < keynum; i++ {
		key := keys.Field(i)
		val := vals.Field(i)

		if val.Kind() == reflect.Ptr {
			val = val.Elem()
		}

		if !val.IsValid() {
			continue
		}

		p := NewParam(key.Name)
		switch val.Kind() {
		case reflect.Struct:
			reflectStructToParams(p, val)
		case reflect.Slice:
			reflectSliceToParams(p, val)
		default:
			p.Type = StringParam
			p.SetValue(val)
		}

		if p == nil {
			continue
		}

		params = append(params, p)
	}

	params.Walk(func(p *Param) {
		// use Walk func built-in logic to assign keys
	})

	return params
}

// reflectStructToParams - map struct of reflect to params include special param type process
func reflectStructToParams(p *Param, val reflect.Value) {
	if !val.CanInterface() {
		p = nil
		return
	}

	if image, ok := val.Interface().(Image); ok {
		imgVal, err := processImage(&image)
		if err != nil {
			log.Printf("ProcessImage: %s", err)
			p = nil
			return
		}
		p.Type = ImageParam
		p.SetValue(imgVal)
		return
	}

	p.Type = StructParam
	p.Params = StructToParams(val)

}

// reflectSliceToParams - map slice of reflect to params
func reflectSliceToParams(p *Param, val reflect.Value) {
	p.Type = SliceParam

	for i := 0; i < val.Len(); i++ {
		// Use index +1 because in template for user not useful see
		// 0 as start number. Only programmers will understand
		itemParam := NewParam(i + 1)
		itemVal := val.Index(i)

		if itemVal.Kind() == reflect.Ptr {
			itemVal = itemVal.Elem()
		}

		if !itemVal.IsValid() {
			continue
		}

		switch itemVal.Kind() {
		case reflect.Struct:
			reflectStructToParams(itemParam, itemVal)
		default:
			itemParam.Type = StringParam
			itemParam.SetValue(itemVal)
		}

		if itemParam == nil {
			continue
		}

		p.Params = append(p.Params, itemParam)
	}
}

// Parse row content to param list
func rowParams(row []byte) ParamList {
	// extract from raw contents
	re := regexp.MustCompile(ParamPattern)
	matches := re.FindAllSubmatch(row, -1)

	if matches == nil || matches[0] == nil {
		return nil
	}

	var params ParamList
	for _, match := range matches {
		p := NewParam(string(match[2]))
		p.RowPlaceholder = string(match[0])
		p.Separator = string(match[3])
		p.Trigger = NewParamTrigger(match[4])
		p.Formatter = NewFormatter(match[4])
		params = append(params, p)
	}
	return params
}

// Walk through params
func (params ParamList) Walk(fn func(*Param)) {
	for _, p := range params {
		fn(p)
		p.Level = 1
		p.Walk(fn, p.Level+1)
	}
}

// WalkWithEnd - recursively apply fn to each Param in the list
func (params ParamList) WalkWithEnd(fn func(*Param) bool) {
	for _, p := range params {
		if fn(p) {
			continue
		}
		p.Params.WalkWithEnd(fn)
	}
}

// FindAllByKey - returns all Params matching the given key
func (params ParamList) FindAllByKey(key string) ParamList {
	keySlice := strings.Split(key, ".")
	var ret ParamList
	params.findAllByKey(nil, nil, 0, 1, keySlice, &ret)
	return ret
}

func (params ParamList) findAllByKey(privParamList, paramList []int, offset, depth int, key []string, paramsIn *ParamList) ([]int, int) {
	if depth > len(key) {
		return nil, 0
	}
	currLev := strings.Join(key[:depth], ".")
	for i, param := range params {
		curr := make([]int, len(paramList))
		copy(curr, paramList)

		if param.parent != nil && param.parent.Type == SliceParam {
			curr = append(curr, i+1)
		}

		if param.Type == StructParam {
			privParamList, offset = param.Params.findAllByKey(privParamList, curr, offset, depth+1, key, paramsIn)
			continue
		}

		if param.CompactKey == currLev || param.AbsoluteKey == currLev {

			if param.Type == SliceParam {
				privParamList, offset = param.Params.findAllByKey(privParamList, curr, offset, depth, key, paramsIn)
				continue
			}

			if depth == len(key) {
				index := 1
				if len(curr) > 0 {
					index = curr[len(curr)-1]
					if len(curr) == len(privParamList) {
						for i := range curr[:len(curr)-1] {
							if privParamList[i] != curr[i] {
								offset += privParamList[len(privParamList)-1]
								break
							}
						}
					}
				}
				param.Index = index + offset
				privParamList = curr
				*paramsIn = append(*paramsIn, param)
				continue
			}

			privParamList, offset = param.Params.findAllByKey(privParamList, curr, offset, depth+1, key, paramsIn)

		}

	}
	return privParamList, offset
}