package proxy

import (
	"encoding/json"
	"fmt"
	"strconv"

	"github.com/peterqiu0516/sub-store/internal/model"
)

// NormalizeProxy ensures name/type are strings and port is a number,
// then strips undefined (nil and "") values.
func NormalizeProxy(input map[string]any) model.ProxyNode {
	if input == nil {
		return nil
	}
	result := make(map[string]any, len(input)+3)
	for k, v := range input {
		result[k] = v
	}
	if name, ok := result["name"]; ok {
		result["name"] = toString(name)
	} else {
		result["name"] = ""
	}
	if t, ok := result["type"]; ok {
		result["type"] = toString(t)
	} else {
		result["type"] = ""
	}
	if port, exists := result["port"]; exists {
		result["port"] = toNumberOrUndefined(port)
	}
	return StripUndefined(result)
}

// IsProxyNode returns true if the node has both a name and a type.
func IsProxyNode(node model.ProxyNode) bool {
	if node == nil {
		return false
	}
	name, ok := node["name"].(string)
	if !ok || name == "" {
		return false
	}
	t, ok := node["type"].(string)
	if !ok || t == "" {
		return false
	}
	return true
}

// StripUndefined removes nil and "" values from a map.
// This mirrors the TS stripUndefined which filters out undefined and "".
func StripUndefined(input map[string]any) map[string]any {
	if input == nil {
		return map[string]any{}
	}
	result := make(map[string]any, len(input))
	for k, v := range input {
		if v == nil {
			continue
		}
		if s, ok := v.(string); ok && s == "" {
			continue
		}
		result[k] = v
	}
	return result
}

// AddPreviewIds adds an "id" field to each proxy computed by StableProxyId.
func AddPreviewIds(proxies []model.ProxyNode) []model.ProxyNode {
	result := make([]model.ProxyNode, len(proxies))
	for i, proxy := range proxies {
		id := StableProxyId(proxy, i)
		merged := make(map[string]any, len(proxy)+1)
		merged["id"] = id
		for k, v := range proxy {
			merged[k] = v
		}
		result[i] = merged
	}
	return result
}

// StableProxyId builds a deterministic identifier from name|type|server|port|index.
func StableProxyId(proxy model.ProxyNode, index int) string {
	return fmt.Sprintf("%s|%s|%s|%s|%d",
		toString(proxy["name"]),
		toString(proxy["type"]),
		toString(proxy["server"]),
		portString(proxy["port"]),
		index,
	)
}

// EnsureUniqueProxyNames appends -2, -3, etc. to duplicate proxy names.
func EnsureUniqueProxyNames(proxies []model.ProxyNode) []model.ProxyNode {
	seen := make(map[string]int, len(proxies))
	result := make([]model.ProxyNode, len(proxies))
	for i, proxy := range proxies {
		if proxy == nil {
			result[i] = proxy
			continue
		}
		name := toString(proxy["name"])
		count := seen[name]
		seen[name] = count + 1
		if count == 0 {
			result[i] = proxy
			continue
		}
		merged := make(map[string]any, len(proxy))
		for k, v := range proxy {
			merged[k] = v
		}
		merged["name"] = fmt.Sprintf("%s-%d", name, count+1)
		result[i] = merged
	}
	return result
}

// toString converts an any value to its string representation.
func toString(v any) string {
	if v == nil {
		return ""
	}
	switch val := v.(type) {
	case string:
		return val
	case bool:
		return strconv.FormatBool(val)
	case float64:
		return strconv.FormatFloat(val, 'f', -1, 64)
	case float32:
		return strconv.FormatFloat(float64(val), 'f', -1, 32)
	case int:
		return strconv.Itoa(val)
	case int64:
		return strconv.FormatInt(val, 10)
	case json.Number:
		return val.String()
	default:
		return fmt.Sprintf("%v", v)
	}
}

// portString returns the string representation of a port value.
func portString(v any) string {
	if v == nil {
		return ""
	}
	return toString(v)
}

// toNumberOrUndefined converts a value to a float64 (Go's JSON number),
// returning nil if the value is nil or cannot be parsed.
func toNumberOrUndefined(v any) any {
	if v == nil {
		return nil
	}
	switch val := v.(type) {
	case float64:
		return val
	case float32:
		return float64(val)
	case int:
		return float64(val)
	case int64:
		return float64(val)
	case string:
		if val == "" {
			return nil
		}
		n, err := strconv.ParseFloat(val, 64)
		if err != nil {
			return nil
		}
		return n
	case bool:
		return nil
	default:
		return nil
	}
}