// ============================================================
//  GlmOcrClient:智谱 GLM-OCR 云端接口(版面解析 layout_parsing)
//  · POST {BaseUrl}  Authorization: Bearer {ApiKey}
//    {"model":"glm-ocr","file":"data:image/png;base64,..."}
//  · 响应 layout_details[页][{label,bbox_2d(归一化),content,width,height}]
//    → label=text 的块转 OcrItem(bbox 映射回裁剪图像素坐标)
//  · 手写字识别(模型内置,无需专用参数);价格 ~0.2 元/百万 tokens
//  · 纯 C# HTTP,无需 Python;引擎切换由 OcrClient 路由
// ============================================================
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Web.Script.Serialization;

namespace 成套报价软件
{
    /// <summary>智谱 GLM-OCR 客户端(单实例)。</summary>
    internal sealed class GlmOcrClient
    {
        private readonly JavaScriptSerializer _json = new JavaScriptSerializer();
        private string _apiKey;
        private string _baseUrl;

        /// <summary>状态提示(未配置Key/请求失败等),接 OcrClient.StatusChanged。</summary>
        public event Action<string> StatusChanged;

        public GlmOcrClient()
        {
            _baseUrl = ReadAppSetting("GlmBaseUrl",
                "https://open.bigmodel.cn/api/paas/v4/layout_parsing");
            try
            {
                // net48 下显式启用 TLS1.2(大模型 API 必须)
                ServicePointManager.SecurityProtocol =
                    ServicePointManager.SecurityProtocol | SecurityProtocolType.Tls12;
            }
            catch { }
        }

        /// <summary>Key 由 OcrClient 从 baidu_ocr.json 的 glm_api_key 注入(热更新)。</summary>
        public void SetApiKey(string key)
        {
            _apiKey = key == null ? "" : key.Trim();
        }

        public bool IsConfigured
        {
            get { return !string.IsNullOrWhiteSpace(_apiKey); }
        }

        private static string ReadAppSetting(string key, string def)
        {
            try
            {
                var v = System.Configuration.ConfigurationManager.AppSettings[key];
                return string.IsNullOrWhiteSpace(v) ? def : v;
            }
            catch { return def; }
        }

        /// <summary>识别一块位图 → 文本块列表(带 bbox 像素坐标)。</summary>
        public Task<List<OcrItem>> RecognizeAsync(Bitmap crop, int timeoutMs)
        {
            if (crop == null || crop.Width <= 0 || crop.Height <= 0)
                return Task.FromResult(new List<OcrItem>());

            if (!IsConfigured)
            {
                Notify("GLM OCR 未配置 API Key(OCR 设置窗口里填智谱 API Key)");
                var tcs0 = new TaskCompletionSource<List<OcrItem>>();
                tcs0.SetException(new Exception(
                    "智谱 GLM-OCR 未配置 API Key。\r\n请到 open.bigmodel.cn 获取 Key," +
                    "在 OCR 设置窗口选择引擎\"智谱 GLM-OCR\"并填入 Key 后保存。"));
                return tcs0.Task;
            }

            return Task.Factory.StartNew(() =>
            {
                var sw = System.Diagnostics.Stopwatch.StartNew();
                try
                {
                    var result = RequestAndParse(crop, timeoutMs);
                    Notify("智谱GLM-OCR·" + result.Count + "条 " + sw.ElapsedMilliseconds + "ms");
                    return result;
                }
                catch
                {
                    throw;
                }
            });
        }

        private List<OcrItem> RequestAndParse(Bitmap crop, int timeoutMs)
        {
            byte[] png;
                using (var ms = new MemoryStream())
                {
                    crop.Save(ms, ImageFormat.Png);
                    png = ms.ToArray();
                }
                // 服务端期望 data URI 或 URL(SDK 自动包装 data URI,此处显式包装)
                string fileField = "data:image/png;base64," + Convert.ToBase64String(png);

                string body = _json.Serialize(new Dictionary<string, object>
                {
                    { "model", "glm-ocr" },
                    { "file", fileField }
                });

                var req = (HttpWebRequest)WebRequest.Create(_baseUrl);
                req.Method = "POST";
                req.ContentType = "application/json";
                req.Headers.Add("Authorization", "Bearer " + _apiKey);
                req.Timeout = timeoutMs;
                req.ReadWriteTimeout = timeoutMs;
                req.Proxy = null;   // 尊重直连,避免系统代理拖慢
                var bytes = Encoding.UTF8.GetBytes(body);
                req.ContentLength = bytes.Length;
                using (var rs = req.GetRequestStream())
                {
                    rs.Write(bytes, 0, bytes.Length);
                }

                string respText;
                try
                {
                    using (var resp = (HttpWebResponse)req.GetResponse())
                    using (var sr = new StreamReader(resp.GetResponseStream(),
                        new UTF8Encoding(false)))
                    {
                        respText = sr.ReadToEnd();
                    }
                }
                catch (WebException wex)
                {
                    string detail = "";
                    try
                    {
                        if (wex.Response != null)
                            using (var sr = new StreamReader(wex.Response.GetResponseStream(),
                                new UTF8Encoding(false)))
                                detail = sr.ReadToEnd();
                    }
                    catch { }
                    string hint = wex.Response == null
                        ? ("网络不可达: " + wex.Message)
                        : ("HTTP " + (int)((HttpWebResponse)wex.Response).StatusCode + " " + detail);
                    throw new Exception("GLM OCR 请求失败: " + hint);
                }

                return ParseResponse(respText, crop.Width, crop.Height);
        }

        /// <summary>解析 layout_parsing 响应 → OcrItem 列表(text 块)。</summary>
        private List<OcrItem> ParseResponse(string respText, int cropW, int cropH)
        {
            var msg = _json.Deserialize<Dictionary<string, object>>(respText);
            if (msg == null) throw new Exception("GLM 响应解析失败(空响应)");
            if (msg.ContainsKey("error"))
            {
                var err = msg["error"] as Dictionary<string, object>;
                string code = err != null && err.ContainsKey("code") ? Convert.ToString(err["code"]) : "?";
                string message = err != null && err.ContainsKey("message") ? Convert.ToString(err["message"]) : respText;
                throw new Exception("GLM OCR 错误 [" + code + "]: " + message);
            }

            var items = new List<OcrItem>();
            var pages = msg.ContainsKey("layout_details")
                ? msg["layout_details"] as System.Collections.ArrayList : null;
            if (pages == null || pages.Count == 0)
                throw new Exception("GLM 响应没有 layout_details(内容: " +
                    (respText.Length > 300 ? respText.Substring(0, 300) : respText) + ")");

            // 单页输入 → 取第一页的块
            var blocks = pages[0] as System.Collections.ArrayList;
            if (blocks == null) return items;

            foreach (Dictionary<string, object> b in blocks)
            {
                string label = b.ContainsKey("label") ? Convert.ToString(b["label"]) : "";
                string content = b.ContainsKey("content") ? Convert.ToString(b["content"]) : "";
                if (string.IsNullOrWhiteSpace(content)) continue;

                var bbox = b.ContainsKey("bbox_2d") ? b["bbox_2d"] as System.Collections.ArrayList : null;
                if (bbox == null || bbox.Count < 4) continue;

                // ★ 实测返回像素坐标;官方文档描述归一化(0~1)。按值域自动兼容:
                //   四个值全部 ≤1.5 → 归一化,乘图尺寸;否则直接当像素用。
                float a0 = Convert.ToSingle(bbox[0]), a1 = Convert.ToSingle(bbox[1]);
                float a2 = Convert.ToSingle(bbox[2]), a3 = Convert.ToSingle(bbox[3]);
                bool normalized = a0 <= 1.5f && a1 <= 1.5f && a2 <= 1.5f && a3 <= 1.5f;
                float x1 = normalized ? a0 * cropW : a0;
                float y1 = normalized ? a1 * cropH : a1;
                float x2 = normalized ? a2 * cropW : a2;
                float y2 = normalized ? a3 * cropH : a3;
                // 裁剪到图内(超界坐标画在页面外会导致蒙版不可见)
                x1 = Math.Max(0, Math.Min(cropW, x1));
                y1 = Math.Max(0, Math.Min(cropH, y1));
                x2 = Math.Max(0, Math.Min(cropW, x2));
                y2 = Math.Max(0, Math.Min(cropH, y2));

                if (label == "table")
                {
                    // ★ 框选多行文字常被判定为表格块(content 为 <table> HTML):
                    //   每个 <tr> 一条文本(单元格空格拼接),行高均分定位。
                    //   必须在 CleanHtml 剥标签之前解析结构。
                    AddTableItems(items, content, x1, y1, x2, y2);
                    continue;
                }
                if (label != "text") continue;   // 图片/公式块跳过
                content = CleanHtmlShared(content);    // 居中块会返回 <div align=..>..</div> 等 HTML
                if (string.IsNullOrWhiteSpace(content)) continue;

                // 多行文本块拆行(content 按 \n,块内均匀分布);清理 Markdown 标记
                // ★ 行间上下各收缩 15%(≤3px):蒙版之间留空隙,不连成一片
                string[] lines = content.Split(new[] { '\r', '\n' },
                    StringSplitOptions.RemoveEmptyEntries);
                float lineH = (y2 - y1) / lines.Length;
                float pad = Math.Min(lineH * 0.15f, 3f);
                for (int i = 0; i < lines.Length; i++)
                {
                    string text = CleanMarkdownShared(lines[i]).Trim();
                    if (text.Length == 0) continue;
                    float ty1 = y1 + lineH * i + pad;
                    float ty2 = y1 + lineH * (i + 1) - pad;
                    if (ty2 - ty1 < 2) { ty1 = y1 + lineH * i; ty2 = ty1 + Math.Max(2, lineH); }
                    items.Add(new OcrItem
                    {
                        Text = text,
                        Box = new[]
                        {
                            new PointF(x1, ty1),
                            new PointF(x2, ty1),
                            new PointF(x2, ty2),
                            new PointF(x1, ty2)
                        },
                        Score = 1f
                    });
                }
            }
            return items;
        }

        private static readonly System.Text.RegularExpressions.Regex _trRegex =
            new System.Text.RegularExpressions.Regex("<tr[^>]*>(.*?)</tr>",
                System.Text.RegularExpressions.RegexOptions.Singleline |
                System.Text.RegularExpressions.RegexOptions.IgnoreCase |
                System.Text.RegularExpressions.RegexOptions.Compiled);
        private static readonly System.Text.RegularExpressions.Regex _tdRegex =
            new System.Text.RegularExpressions.Regex("<t[dh][^>]*>(.*?)</t[dh]>",
                System.Text.RegularExpressions.RegexOptions.Singleline |
                System.Text.RegularExpressions.RegexOptions.IgnoreCase |
                System.Text.RegularExpressions.RegexOptions.Compiled);

        /// <summary>表格块 → 每 tr 一条 item(td 内容空格拼接),行高均分 bbox。</summary>
        private static void AddTableItems(List<OcrItem> items, string tableHtml,
            float x1, float y1, float x2, float y2)
        {
            var rows = new List<string>();
            foreach (System.Text.RegularExpressions.Match tr in _trRegex.Matches(tableHtml))
            {
                var cells = new List<string>();
                foreach (System.Text.RegularExpressions.Match td in _tdRegex.Matches(tr.Groups[1].Value))
                {
                    string cell = CleanHtmlShared(td.Groups[1].Value).Trim();
                    if (cell.Length > 0) cells.Add(cell);
                }
                if (cells.Count > 0) rows.Add(string.Join(" ", cells.ToArray()));
            }
            if (rows.Count == 0) return;
            float rowH = (y2 - y1) / rows.Count;
            float pad = Math.Min(rowH * 0.15f, 3f);   // 行间留空隙,蒙版不连片
            for (int i = 0; i < rows.Count; i++)
            {
                float ty1 = y1 + rowH * i + pad;
                float ty2 = y1 + rowH * (i + 1) - pad;
                if (ty2 - ty1 < 2) { ty1 = y1 + rowH * i; ty2 = ty1 + Math.Max(2, rowH); }
                items.Add(new OcrItem
                {
                    Text = rows[i],
                    Box = new[]
                    {
                        new PointF(x1, ty1),
                        new PointF(x2, ty1),
                        new PointF(x2, ty2),
                        new PointF(x1, ty2)
                    },
                    Score = 1f
                });
            }
        }

        private static readonly System.Text.RegularExpressions.Regex _htmlTag =
            new System.Text.RegularExpressions.Regex("<[^>]*>",
                System.Text.RegularExpressions.RegexOptions.Compiled);

        /// <summary>
        /// 剥离 GLM content 里的 HTML 片段(居中块返回 div 等)与常见实体;
        /// 标签替换为空格,避免前后文字误粘连;连续空格合并。
        /// </summary>
        internal static string CleanHtmlShared(string s)
        {
            if (string.IsNullOrEmpty(s)) return s;
            if (s.IndexOf('<') >= 0)
            {
                s = _htmlTag.Replace(s, " ");
                s = s.Replace("&nbsp;", " ").Replace("&amp;", "&")
                     .Replace("&lt;", "<").Replace("&gt;", ">")
                     .Replace("&quot;", "\"").Replace("&apos;", "'");
            }
            while (s.Contains("  ")) s = s.Replace("  ", " ");
            return s;
        }

        /// <summary>
        /// 清理 GLM 返回 content 里的 Markdown 标记(★保守规则,不伤正文):
        /// · 行首 "##"/"#" 标题井号(仅行首;"2#配电箱" 中间的 # 保留)
        /// · 成对 **加粗** 星号、行首 "- "/"* " 列表标记
        /// </summary>
        internal static string CleanMarkdownShared(string s)
        {
            if (string.IsNullOrEmpty(s)) return s;
            // 行首标题:# 开头且后跟空格/更多#/行尾 → 剥掉行首所有 #
            string t = s.TrimStart();
            if (t.StartsWith("#"))
            {
                int i = 0;
                while (i < t.Length && t[i] == '#') i++;
                // "#..." 后是空格或行尾才视为标题标记
                if (i >= t.Length || t[i] == ' ' || t[i] == '\t')
                    t = t.Substring(i).TrimStart();
                // 否则(如 "#5 线缆")保留原样
                else t = s;
            }
            // 行首列表标记
            if (t.StartsWith("- ") || t.StartsWith("* "))
                t = t.Substring(2);
            // 成对 ** (加粗) 去星号
            if (t.Contains("**"))
                t = t.Replace("**", "");
            return t;
        }

        private void Notify(string s)
        {
            var h = StatusChanged;
            if (h != null) h(s);
        }
    }
}