import 'dart:io';
import 'dart:convert';
import 'package:intl/intl.dart';

// name of executable
String exename = "nostr_console";
String version = "0.0.3";

// well known disposable test private key
const String gDefaultPrivateKey = "9d00d99c8dfad84534d3b395280ca3b3e81be5361d69dc0abf8e0fdf5a9d52f9";
const String gDefaultPublicKey  = "e8caa2028a7090ffa85f1afee67451b309ba2f9dee655ec8f7e0a02c29388180";
String userPrivateKey = gDefaultPrivateKey;
String userPublicKey  = gDefaultPublicKey;

const int  gMinValidTextWidth = 60; // minimum text width acceptable
const int  gDefaultTextWidth = 120; // default text width
int        gTextWidth = gDefaultTextWidth; // is changed by --width option
const int  gSpacesPerDepth = 8;     // constant
int        gNumLeftMarginSpaces = 0;// this number is modified in main 
String     gAlignment = "center";   // is modified in main if --align argument is given
const int  gapBetweenTopTrees = 1;

// after depth of maxDepthAllowed the thread is re-aligned to left by leftShiftThreadBy
const int  gMinimumDepthAllowed = 2;
const int  gMaximumDepthAllowed  = 12;
const int  gDefaultMaxDepth     = 4;
int        maxDepthAllowed      = gDefaultMaxDepth;
const int  leftShiftThreadsBy   = 2;

// 33 yellow, 31 red, 34 blue, 35 magenta. Add 60 for bright versions. 
const String commentColor = "\x1B[32m"; // green
const String notificationColor = "\x1b[36m"; // cyan
const String warningColor = "\x1B[31m"; // red
const String colorEndMarker = "\x1B[0m";

//String defaultServerUrl = 'wss://relay.damus.io';
String defaultServerUrl = 'wss://nostr-relay.untethr.me';

// dummy account pubkey
const String gDummyAccountPubkey = "Non";

// By default the threads that were started in last one day are shown
// this can be changed with 'days' command line argument
int gNumLastDays     = 1; 

// global user names from kind 0 events, mapped from public key to user name
Map<String, String> gKindONames = {}; 

// global reactions entry. Map of form <if of event reacted to, List of Reactors>
// reach Reactor is a list of 2-elements ( first is public id of reactor, second is comment)
Map< String, List<List<String>> > gReactions = {};

// global contact list of each user, including of the logged in user.
// maps from pubkey of a user, to the latest contact list of that user, which is the latest kind 3 message
// is updated as kind 3 events are received 
Map< String, List<Contact>> gContactLists = {};

// bots ignored to reduce spam
List<String> gBots = [  "3b57518d02e6acfd5eb7198530b2e351e5a52278fb2499d14b66db2b5791c512",  // robosats orderbook
                        "887645fef0ce0c3c1218d2f5d8e6132a19304cdc57cd20281d082f38cfea0072",  // bestofhn
                        "f4161c88558700d23af18d8a6386eb7d7fed769048e1297811dcc34e86858fb2"   // bitcoin_bot
                      ];

//const String gDefaultEventsFilename = "events_store_nostr.txt";
String       gEventsFilename        = ""; // is set in arguments, and if set, then file is read from and written to

int gDebug = 0;

void printDepth(int d) {
  for( int i = 0; i < gSpacesPerDepth * d + gNumLeftMarginSpaces; i++) {
    stdout.write(" ");
  }
}

String getNumSpaces(int num) {
  String s = "";
  for( int i = 0; i < num; i++) {
    s += " ";
  }
  return s;
}

String getNumDashes(int num) {
  String s = "";
  for( int i = 0; i < num; i++) {
    s += "-";
  }
  return s;
}

String rightShiftContent(String s, int numSpaces) {
  String newString = "";
  int    newlineCounter = 0;
  String spacesString = getNumSpaces(numSpaces + gNumLeftMarginSpaces);

  for(int i = 0; i < s.length; i++) {
    if( s[i] == '\n') {
      newString += "\n";
      newString += spacesString;
      newlineCounter = 0;
    } else {
      if( newlineCounter >= (gTextWidth - numSpaces)) {
        newString += "\n";
        newString += spacesString;
        newlineCounter = 0;
      } 
      newString += s[i];
    }
    newlineCounter++;
  }
  return newString;
}

// The contact only stores id and relay of contact. The actual name is stored in a global variable/map
class Contact {
  String id, relay;
  Contact(this.id, this.relay);

  @override 
  String toString() {
    return 'id: $id ( ${getAuthorName(id)})     relay: $relay';
  }
}

class EventData {
  String             id;
  String             pubkey;
  int                createdAt;
  int                kind;
  String             content;
  List<String>       eTagsRest;// rest of e tags
  List<String>       pTags;// list of p tags for kind:1
  List<List<String>> tags;
  bool               isNotification; // whether its to be highlighted using highlight color
  Set<String>       newLikes;    //

  List<Contact> contactList = []; // used for kind:3 events, which is contact list event
  
  String getParent() {
    if( eTagsRest.isNotEmpty) {
      return eTagsRest[eTagsRest.length - 1];
    }
    return "";
  }

  EventData(this.id, this.pubkey, this.createdAt, this.kind, this.content, this.eTagsRest, this.pTags,
            this.contactList, this.tags, this.newLikes, {this.isNotification = false});
  
  factory EventData.fromJson(dynamic json) {
    List<Contact> contactList = [];

    List<String>       eTagsRead = [];
    List<String>       pTagsRead = [];
    List<List<String>> tagsRead = [];

    var jsonTags = json['tags'];      
    var numTags = jsonTags.length;

    // NIP 02: if the event is a contact list type, then populate contactList
    if(json['kind'] == 3) {
      for( int i = 0; i < numTags; i++) {
        var tag = jsonTags[i];
        var n = tag.length;
        String server = defaultServerUrl;
        if( n >=3 ) {
          server = tag[2].toString();
          if( server == 'wss://nostr.rocks' || server == "wss://nostr.bitcoiner.social") {
            server = defaultServerUrl;
          }
          //server = defaultServerUrl;
        }
        Contact c = Contact(tag[1] as String, server);
        
        contactList.add(c);
      }
    } else {
      if ( json['kind'] == 1 || json['kind'] == 7) {
        for( int i = 0; i < numTags; i++) {
          var tag = jsonTags[i];
          //stdout.write(tag);
          //print(tag.runtimeType);
          if( tag.isEmpty) {
            continue;
          }
          if( tag[0] == "e") {
            eTagsRead.add(tag[1]);
          } else {
            if( tag[0] == "p") {
              pTagsRead.add(tag[1]);
            }
          }
          List<String> t = [];
          t.add(tag[0]);
          t.add(tag[1]);
          tagsRead.add(t);

          // TODO add other tags
        }
      }
    }

    if(gDebug >= 2 ) {
      print("----------------------------------------Creating EventData with content: ${json['content']}");
    }

    String checkEventId = "c39c03f70a88207fdecd356cbbb05b508ee28115fba03f55d6c5e852086b4ddf";
    if( json['id'] == checkEventId) {
      if(gDebug >= 1) print("got message: $checkEventId");
    }

    return EventData(json['id'] as String,      json['pubkey'] as String, 
                     json['created_at'] as int, json['kind'] as int,
                     json['content'].trim() as String, 
                     eTagsRead,                 pTagsRead,
                     contactList,               tagsRead, 
                     {});
  }

  String expandMentions(String content) {
    if( tags.isEmpty) {
      return content;
    }

    // just check if there is any square bracket in comment, if not we return
    String squareBracketStart = "[", squareBracketEnd = "]";
    if( !content.contains(squareBracketStart) || !content.contains(squareBracketEnd) ) {
      return content;
    }

    // replace the patterns
    List<String> placeHolders = ["#[0]", "#[1]", "#[2]", "#[3]", "#[4]", "#[5]", "#[6]", "#[7]" ];
    for(int i = 0; i < placeHolders.length; i++) {
      int     index = -1;
      Pattern p     = placeHolders[i];
      if( (index = content.indexOf(p)) != -1 ) {
        if( i >= tags.length) {
          continue;
        }

        if( tags[i].isEmpty || tags[i].length < 2) {
          continue;
        }

        String author = getAuthorName(tags[i][1]);
        content = "${content.substring(0, index)} @$author${content.substring(index + 4)}";
      }
    }
    return content;
  }

  // prints event data in the format that allows it to be shown in tree form by the Tree class
  void printEventData(int depth) {
    int n = 3;
    String maxN(String v)       => v.length > n? v.substring(0,n) : v.substring(0, v.length);
    void   printInColor(String s, String commentColor) => stdout.supportsAnsiEscapes ?stdout.write("$commentColor$s$colorEndMarker"):stdout.write(s);

    DateTime dTime = DateTime.fromMillisecondsSinceEpoch(createdAt *1000);
    
   // TODO do it in one call
   final df1 = DateFormat('hh:mm a');
   final df2 = DateFormat(DateFormat.YEAR_ABBR_MONTH_DAY);
   String strDate = df1.format(DateTime.fromMillisecondsSinceEpoch(createdAt*1000));
   strDate += " ${df2.format(DateTime.fromMillisecondsSinceEpoch(createdAt*1000))}";
    if( createdAt == 0) {
      print("debug: createdAt == 0 for event $content");
    }

    content = expandMentions(content);
    String contentShifted = rightShiftContent(content, gSpacesPerDepth * depth + 10);
    
    printDepth(depth);
    stdout.write("+-------+\n");
    printDepth(depth);
    String name = getAuthorName(pubkey);
    stdout.write("|Author : $name  id: ${maxN(id)}  Time: $strDate\n");
    printReaction(depth);    // only prints if there are any likes/reactions
    printDepth(depth);
    stdout.write("|Message: ");
    if( isNotification) {
      printInColor(contentShifted, notificationColor);
      isNotification = false;
    } else {
      printInColor(contentShifted, commentColor);
    }
  }

  // looks up global map of reactions, if this event has any reactions, and then prints the reactions
  // in appropriate color( in case one is a notification, which is stored in member variable)
  void printReaction(int depth) {
    if( gReactions.containsKey(id)) {
      String reactorNames = "|Likes  : ";
      printDepth(depth);
      //print("All Likes:");
      int numReactions = gReactions[id]?.length??0;
      List<List<String>> reactors = gReactions[id]??[];
      for( int i = 0; i <numReactions; i++) {
        String reactorId = reactors[i][0];
        if( newLikes.contains(reactorId)) {
          // colorify
          reactorNames += notificationColor + getAuthorName(reactorId) + colorEndMarker;
        } else {
          reactorNames += getAuthorName(reactorId);
        }
        
        if( i < numReactions -1) {
          reactorNames += ", ";
        }
      }
      print(reactorNames);
      newLikes.clear();
    }
  }

  @override
  String toString() {
    if( id == "non") {
      return '';
    }

    String max3(String v) => v.length > 3? v.substring(0,3) : v.substring(0, v.length);
    DateTime dTime = DateTime.fromMillisecondsSinceEpoch(createdAt *1000);
    if( createdAt == 0) {
      print("createdAt == 0 for event $content");
    }
    return '\n-------+-------------\nAuthor : ${max3(pubkey)}\nMessage: $content\n\nid     : ${max3(id)}     Time: $dTime     Kind: $kind';
  }
}

// This is mostly a placeholder for EventData. TODO combine both?
class Event {
  String event;
  String id;
  EventData eventData;
  String originalJson;
  List<String> seenOnRelays;

  Event(this.event, this.id, this.eventData, this.seenOnRelays, this.originalJson);

  factory Event.fromJson(String d, String relay) {
    try {
      dynamic json = jsonDecode(d);
      if( json.length < 3) {
        String e = "";
        e = json.length > 1? json[0]: "";
        return Event(e,"",EventData("non","", 0, 0, "", [], [], [], [[]], {}), [relay], "[json]");
      }
      return Event(json[0] as String, json[1] as String,  EventData.fromJson(json[2]), [relay], d );
    } on Exception catch(e) {
      return Event("","",EventData("non","", 0, 0, "", [], [], [], [[]], {}), [relay], "[json]");
    }
  }

  void printEvent(int depth) {
    eventData.printEventData(depth);
    //stdout.write("\n$originalJson \n");
  }

  @override 
  String toString() {
    return '$eventData     Seen on: ${seenOnRelays[0]}\n';
  }
}

List<String> getpTags(List<Event> events) {
  List<String> pTags = [];
  for(int i = 0; i < events.length; i++) {
    pTags.addAll(events[i].eventData.pTags);
  }

  // remove duplicate pTags events
  Set tempPtags = {};
  pTags.retainWhere((x) => tempPtags.add(x));

  return pTags;
}

// If given event is kind 0 event, then populates gKindONames with that info
void processKind0Event(Event e) {
  if( e.eventData.kind != 0) {
    return;
  }

  String content = e.eventData.content;
  if( content.isEmpty) {
    return;
  }
  try {
    dynamic json = jsonDecode(content);
    if(json["name"] != Null) {
      gKindONames[e.eventData.pubkey] = json["name"]??"";
    }
  } catch(ex) {
    if( gDebug != 0) print("Warning: In processKind0Event: caught exception for content: ${e.eventData.content}");
  }
}

// returns name by looking up global list gKindONames, which is populated by kind 0 events
String getAuthorName(String pubkey) {
  String max3(String v) => v.length > 3? v.substring(0,3) : v.substring(0, v.length);
  String name = gKindONames[pubkey]??max3(pubkey);
  return name;
}

List<Event> readEventsFromFile(String filename) {
  List<Event> events = [];
  final File  file   = File(filename);

  // sync read
  try {
    List<String> lines = file.readAsLinesSync();
    for( int i = 0; i < lines.length; i++ ) {
          Event e = Event.fromJson(lines[i], "");
          events.add(e);
    }
  } on Exception catch(err) {
    print("Cannot open file $gEventsFilename");
  }

  return events;
}

Event? getContactEvent(List<Event> events, String pubkey) {

    // get the latest kind 3 event for the user, which lists his 'follows' list
    int latestContactsTime = 0, latestContactIndex = -1;
    for( int i = 0; i < events.length; i++) {
      var e = events[i];
      if( e.eventData.pubkey == pubkey && e.eventData.kind == 3 && latestContactsTime < e.eventData.createdAt) {
        latestContactIndex = i;
        latestContactsTime = e.eventData.createdAt;
      }
    }

    // if contact list was found, get user's feed, and keep the contact list for later use 
    if (latestContactIndex != -1) {
      return events[latestContactIndex];
    }

    return null;
}

// for the user userPubkey, returns the relay of its contact contactPubkey
String getRelayOfUser(String userPubkey, String contactPubkey) {

  if(gDebug > 0) print("In getRelayOfUser: Searching relay for contact $contactPubkey" );

  String relay = "";
  if( userPubkey == "" || contactPubkey == "") {
    return "";
  }

  if( gContactLists.containsKey(userPubkey)) {
    List<Contact>? contacts = gContactLists[userPubkey];
    if( contacts != null) {
      for( int i = 0; i < contacts.length; i++) {
        if( gDebug > 0) print(  contacts[i].toString()  );
        if( contacts[i].id == contactPubkey) {
          relay = contacts[i].relay;
          if(gDebug > 0) print("In getRelayOfUser: found relay $relay for contact $contactPubkey" );
          return relay;
        }
      }
    }
  }
  // if not found return empty string
  return relay;
}