// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
// All rights reserved.

// simple-var-store.go
package expr

import (
	"fmt"
	"strings"
)

type SimpleVarStore struct {
	varStore map[string]any
}

func NewSimpleVarStore() *SimpleVarStore {
	return &SimpleVarStore{
		varStore: make(map[string]any),
	}
}

func (ctx *SimpleVarStore) cloneVars() (vars map[string]any) {
	return CloneFilteredMap(ctx.varStore, func(name string) bool { return name[0] != '@' })
}

func (ctx *SimpleVarStore) Clone() (clone ExprContext) {
	// fmt.Println("*** Cloning context ***")
	clone = &SimpleVarStore{
		varStore: ctx.cloneVars(),
	}
	return clone
}

func (ctx *SimpleVarStore) GetVar(varName string) (v any, exists bool) {
	v, exists = ctx.varStore[varName]
	return
}

func (ctx *SimpleVarStore) UnsafeSetVar(varName string, value any) {
	// fmt.Printf("[%p] setVar(%v, %v)\n", ctx, varName, value)
	ctx.varStore[varName] = value
}

func (ctx *SimpleVarStore) SetVar(varName string, value any) {
	// fmt.Printf("[%p] SetVar(%v, %v)\n", ctx, varName, value)
	if allowedValue, ok := fromGenericAny(value); ok {
		ctx.varStore[varName] = allowedValue
	} else {
		panic(fmt.Errorf("unsupported type %T of value %v", value, value))
	}
}

func (ctx *SimpleVarStore) EnumVars(acceptor func(name string) (accept bool)) (varNames []string) {
	varNames = make([]string, 0)
	for name := range ctx.varStore {
		if acceptor != nil {
			if acceptor(name) {
				varNames = append(varNames, name)
			}
		} else {
			varNames = append(varNames, name)
		}
	}
	return
}

func (ctx *SimpleVarStore) GetFuncInfo(name string) (f ExprFunc, exists bool) {
	return
}

func (ctx *SimpleVarStore) Call(name string, args []any) (result any, err error) {
	return
}

func (ctx *SimpleVarStore) RegisterFunc(name string, functor Functor, minArgs, maxArgs int) {
}

func (ctx *SimpleVarStore) EnumFuncs(acceptor func(name string) (accept bool)) (funcNames []string) {
	return
}

func varsCtxToBuilder(sb *strings.Builder, ctx ExprContext, indent int) {
	sb.WriteString("vars: {\n")
	first := true
	for _, name := range ctx.EnumVars(func(name string) bool { return name[0] != '_' }) {
		if first {
			first = false
		} else {
			sb.WriteByte(',')
			sb.WriteByte('\n')
		}

		value, _ := ctx.GetVar(name)
		sb.WriteString(strings.Repeat("\t", indent+1))
		sb.WriteString(name)
		sb.WriteString(": ")
		if f, ok := value.(Formatter); ok {
			sb.WriteString(f.ToString(0))
		} else if _, ok = value.(Functor); ok {
			sb.WriteString("func(){}")
			// } else if _, ok = value.(map[any]any); ok {
			// 	sb.WriteString("dict{}")
		} else {
			sb.WriteString(fmt.Sprintf("%v", value))
		}
	}
	sb.WriteString(strings.Repeat("\t", indent))
	sb.WriteString("\n}\n")
}

func varsCtxToString(ctx ExprContext, indent int) string {
	var sb strings.Builder
	varsCtxToBuilder(&sb, ctx, indent)
	return sb.String()
}

func (ctx *SimpleVarStore) ToString(opt FmtOpt) string {
	var sb strings.Builder
	varsCtxToBuilder(&sb, ctx, 0)
	return sb.String()
}