using System.Text.RegularExpressions;
using Microsoft.Extensions.Configuration;

namespace URLNotesGrabberCORE
{
    // Port of ThreeTxtFileHelper RunIngestMode. Scans a root folder for .txt files,
    // parses Tumblr-export fields (multi-line aware, prefix-driven), upserts each
    // post into TL.db.Posts via DataAccess.UpsertPostFromTextFile.
    public static class IngestMode
    {
        public static int Run(IConfiguration config, string[] args)
        {
            string? targetBlog = args.Length > 0 ? args[0]?.Trim() : null;
            if (string.IsNullOrWhiteSpace(targetBlog)) targetBlog = null;

            string? rootPath = config["appSettings:PathTTRoot"];
            if (string.IsNullOrWhiteSpace(rootPath))
                rootPath = config["appSettings:PathInput"];

            if (string.IsNullOrWhiteSpace(rootPath))
            {
                Console.WriteLine("Ingest: no root path configured. Set appSettings:PathTTRoot or appSettings:PathInput.");
                return 1;
            }

            if (!Directory.Exists(rootPath))
            {
                Console.WriteLine($"Directory not found: {rootPath}");
                return 1;
            }

            DataAccess.EnsureTTFileHelperColumnsExist();

            string prefixesPath = config["appSettings:PathPrefixes"] ?? "prefixes.txt";
            if (!Path.IsPathRooted(prefixesPath))
                prefixesPath = Path.Combine(AppContext.BaseDirectory, prefixesPath);

            if (!File.Exists(prefixesPath))
            {
                Console.WriteLine($"Prefixes file not found: {prefixesPath}");
                return 1;
            }

            var allowedPrefixes = new HashSet<string>(File.ReadLines(prefixesPath), StringComparer.OrdinalIgnoreCase);
            Console.WriteLine($"Loaded {allowedPrefixes.Count} prefixes from {prefixesPath}");

            Console.WriteLine($"========== Ingest Settings ==========");
            Console.WriteLine($"Root path: {rootPath}");
            Console.WriteLine($"Blog filter: {(targetBlog == null ? "(all blogs)" : targetBlog)}");
            Console.WriteLine($"=====================================");

            var txtFiles = new List<string>();
            try
            {
                var dirs = Directory.GetDirectories(rootPath, "*", SearchOption.AllDirectories);
                Console.WriteLine($"Found {dirs.Length} directories under root.");
                foreach (var dir in dirs)
                {
                    try { txtFiles.AddRange(Directory.GetFiles(dir, "*.txt")); }
                    catch (Exception ex) { Console.WriteLine($"  Skipping {dir}: {ex.Message}"); }
                }
                txtFiles.AddRange(Directory.GetFiles(rootPath, "*.txt"));
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error scanning root: {ex.Message}");
                return 1;
            }

            Console.WriteLine($"Processing {txtFiles.Count} .txt file(s)...");

            int filesProcessed = 0;
            int filesSkipped = 0;
            int postsTouched = 0;

            try
            {
                DataAccess.EnableImportModePragmas();
                DataAccess.BeginImportSession();

                foreach (string file in txtFiles)
                {
                    try
                    {
                        string rawBlogName = Path.GetFileName(Path.GetDirectoryName(file) ?? "unknown");
                        string blogName = Regex.Replace(rawBlogName, @"_\d+$", "");
                        string postType = Path.GetFileNameWithoutExtension(file);

                        if (targetBlog != null && !string.Equals(blogName, targetBlog, StringComparison.OrdinalIgnoreCase))
                        {
                            filesSkipped++;
                            continue;
                        }

                        filesProcessed++;
                        if (filesProcessed % 50 == 0 || filesProcessed == 1)
                            Console.WriteLine($"[{filesProcessed}/{txtFiles.Count}] {Path.GetFileName(file)}");

                        string currentPostId = "";
                        var currentPostData = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);

                        void Flush()
                        {
                            if (!string.IsNullOrWhiteSpace(currentPostId) && currentPostData.Count > 0)
                            {
                                UpsertPostFromParsedData(blogName, currentPostId, postType, currentPostData);
                                postsTouched++;
                            }
                        }

                        var lines = File.ReadAllLines(file);
                        int lineIndex = 0;
                        while (lineIndex < lines.Length)
                        {
                            string line = lines[lineIndex];
                            string searchText = line.Length > 25 ? line.Substring(0, 25) : line;
                            int colonIndex = searchText.IndexOf(": ");

                            if (colonIndex > 0)
                            {
                                string prefix = line.Substring(0, colonIndex).Trim();
                                if (!string.IsNullOrWhiteSpace(prefix) && allowedPrefixes.Contains(prefix))
                                {
                                    if (string.Equals(prefix, "Post ID", StringComparison.OrdinalIgnoreCase))
                                    {
                                        Flush();
                                        currentPostId = line.Substring(colonIndex + 2).Trim();
                                        currentPostData.Clear();
                                        lineIndex++;
                                        continue;
                                    }

                                    var valueLines = new List<string> { line.Substring(colonIndex + 2).Trim() };
                                    int nextLineIndex = lineIndex + 1;
                                    while (nextLineIndex < lines.Length)
                                    {
                                        string nextLine = lines[nextLineIndex];
                                        string nextSearch = nextLine.Length > 25 ? nextLine.Substring(0, 25) : nextLine;
                                        int nextColon = nextSearch.IndexOf(": ");
                                        if (nextColon > 0)
                                        {
                                            string nextPrefix = nextLine.Substring(0, nextColon).Trim();
                                            if (!string.IsNullOrWhiteSpace(nextPrefix) && allowedPrefixes.Contains(nextPrefix))
                                                break;
                                        }
                                        valueLines.Add(nextLine);
                                        nextLineIndex++;
                                    }

                                    currentPostData[prefix] = string.Join("\n", valueLines);
                                    lineIndex = nextLineIndex;
                                    continue;
                                }
                            }
                            lineIndex++;
                        }

                        Flush();
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine($"  ERROR processing file {file}: {ex.Message}");
                    }
                }
            }
            finally
            {
                DataAccess.EndImportSession();
                DataAccess.RestoreImportModePragmas();
            }

            Console.WriteLine($"\nIngest complete. Files processed: {filesProcessed}. Files skipped (blog filter): {filesSkipped}. Posts touched: {postsTouched}.");
            return 0;
        }

        private static void UpsertPostFromParsedData(string blogName, string postId, string postType, Dictionary<string, string> data)
        {
            string? G(string key) => data.TryGetValue(key, out var v) ? v : null;
            string? hasImageStr = G("Has Image");
            bool hasImage = !string.IsNullOrWhiteSpace(hasImageStr)
                && (hasImageStr.Equals("true", StringComparison.OrdinalIgnoreCase)
                    || hasImageStr == "1"
                    || hasImageStr.Equals("yes", StringComparison.OrdinalIgnoreCase));

            DataAccess.UpsertPostFromTextFile(
                blogName: blogName,
                postID: postId,
                reblogURL: G("reblog URL"),
                postDate: G("Date"),
                postURL: G("Post URL"),
                slug: G("Slug"),
                reblogKey: G("Reblog Key"),
                reblogName: G("Reblog Name"),
                summary: G("Summary"),
                quote: G("Quote"),
                body: G("Body"),
                tags: G("Tags"),
                link: G("Link"),
                photoURL: G("Photo URL"),
                photoCaption: G("Photo Caption"),
                downloadedFiles: G("Downloaded Files"),
                audioCaption: G("Audio Caption"),
                question: G("Question"),
                answer: G("Answer"),
                title: G("Title"),
                postType: postType,
                hasImage: hasImage);
        }
    }
}