using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;

namespace SoyText
{
    public enum FoundHandlerAction { End, Accept, Ignore };
    public delegate FoundHandlerAction FoundHandler(Document d);
    public class DocumentSet
    {
        public int maxHandle = -1;
        internal Workspace workspace;
        DocumentList cache=null;
        public String stateDir(DocumentState state)
        {
            return workspace.home + "/document/" + state;
        }
        public String getFileName(int handle, DocumentState state)
        {
            return stateDir(state) + "/" + handle + ".txt";
        }
        public DocumentSet(Workspace w)
        {
            workspace = w;
        }
        public static int cnt=0;
        public Document createDocumentWithNewHandle()
        {
            return createDocument(createHandle());
        }
        public Document createDocument()
        {
            var d = new Document(this);
            cnt++;
            //if (cnt >= 2) throw new Exception("cnt over " + cnt);
            return addToCache(d);
        }
        public Document createDocument(int handle)
        {
            var d=new Document(this, handle);
            return addToCache(d);
        }
        private Document addToCache(Document d)
        {
            if (cache == null) cache = new DocumentList();
            lock (cache)
            {
                cache.Add(-d.uniqueLastUpdate, d);
            }
            return d;
        }
        public int byRecency(Document d1, Document d2)
        {
            long d = d1.lastUpdate - d2.lastUpdate;
            return (d == 0 ? 0 : (d < 0 ? 1 : -1));
        }
        public DocumentList getRecents()
        {
            if (cache != null) return cache;
            Debug.print("文書一覧取得中...");
            //var res = new DocumentList();
            
            searchMax(DocumentState.active, true);
            searchMax(DocumentState.archived, false);
            searchMax(DocumentState.indexed,true);
            if (cache == null) cache = new DocumentList();
            Debug.print("文書一覧並べ替え中...");
            //res.Sort(byRecency);
            Debug.print("END: 文書一覧並べ替え中...");
            
            return cache;
        }
        Dictionary<DocumentState, int> docCount;
        private void searchMax(DocumentState s, bool add)
        {
            foreach (string fileName
               in Mkdir.getFiles(stateDir(s)))
            {
                var m = Regex.Match(fileName, @"(\d+).txt$");
                if (m.Success)
                {
                    var r = m.Groups[1].Value;
                    var handle = Int32.Parse(r);
                    if (handle > maxHandle) maxHandle = handle;
                    if (add) createDocument(handle);
                }
            }
        }
        public int createHandle()
        {
            if (maxHandle < 0) getRecents();
            maxHandle++;
            return maxHandle;
        }
        public DocumentSercher createDocumentSearcher(String kw, FoundHandler f)
        {
            var s = new DocumentSercher();
            s.searchCondition = SearchCondition.fromExpression(kw);
            s.foundHandler = f;
            s.documentSet = this;
            return s;
        }
        public SortedList<long,Document> search(String kw, FoundHandler f)
        {
            var s = createDocumentSearcher(kw, f);
            return s.search();
        }
        
        private DocumentList exactSearch(Token t)
        {

            var res = new DocumentList();
            if (!File.Exists(t.documentPath)) return res;
            foreach (var ln in File.ReadAllLines(t.documentPath))
            {
                var flds = ln.Split('\t');
                if (flds[0].Equals("")) continue;
                var handle = Int32.Parse(flds[0]);
                if (File.Exists(getFileName(handle, DocumentState.indexed)))
                {
                    var d = new Document(this, handle);
                    res.Add(d.uniqueLastUpdate, d);
                    //res.Add(createDocument(handle));
                }
            }
            return res;
        }
        public Document getOldestActiveDocument()
        {
            var r = getRecents();
            return r[0];
        }
    }
}