package uiaselector

import (
	"bytes"
	"encoding/json"
	"fmt"
	"os"
	"strings"
)

type DumpResponse struct {
	OK    bool      `json:"ok"`
	Data  *DumpData `json:"data"`
	Error any       `json:"error"`
}

type DumpData struct {
	Root *Node `json:"root"`
}

type Node struct {
	Name         string `json:"name"`
	ControlType  string `json:"control_type"`
	AutomationID string `json:"automation_id"`
	ClassName    string `json:"class_name"`
	FrameworkID  string `json:"framework_id"`
	IsEnabled    *bool  `json:"is_enabled"`
	IsOffscreen  *bool  `json:"is_offscreen"`
	Bounds       any    `json:"bounds"`
	Children     []Node `json:"children"`
}

func LoadDumpFile(path string) (*Node, error) {
	content, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}
	content = normalizeDumpJSON(content)
	var response DumpResponse
	if err := json.Unmarshal(content, &response); err != nil {
		return nil, err
	}
	if !response.OK {
		return nil, fmt.Errorf("dump response ok=false: %v", response.Error)
	}
	if response.Data == nil || response.Data.Root == nil {
		return nil, fmt.Errorf("dump response has no data.root")
	}
	return response.Data.Root, nil
}

func CountNodes(root *Node) int {
	if root == nil {
		return 0
	}
	count := 1
	for i := range root.Children {
		count += CountNodes(&root.Children[i])
	}
	return count
}

func normalizeDumpJSON(content []byte) []byte {
	content = bytes.TrimPrefix(content, []byte{0xEF, 0xBB, 0xBF})
	source := string(content)
	var out strings.Builder
	out.Grow(len(source))

	inString := false
	escaped := false
	for i := 0; i < len(source); {
		ch := source[i]
		if inString {
			out.WriteByte(ch)
			if escaped {
				escaped = false
			} else if ch == '\\' {
				escaped = true
			} else if ch == '"' {
				inString = false
			}
			i++
			continue
		}

		if ch == '"' {
			inString = true
			out.WriteByte(ch)
			i++
			continue
		}

		switch {
		case strings.HasPrefix(source[i:], "-Infinity"):
			out.WriteString("null")
			i += len("-Infinity")
		case strings.HasPrefix(source[i:], "Infinity"):
			out.WriteString("null")
			i += len("Infinity")
		case strings.HasPrefix(source[i:], "NaN"):
			out.WriteString("null")
			i += len("NaN")
		default:
			out.WriteByte(ch)
			i++
		}
	}
	return []byte(out.String())
}