#include <cassert>
#include <termio.h>

#include "config.h"
#include "manager.h"
#include "throw.h"

using namespace std;


Manager::Manager()
	:activeIdx(-1){}

Manager::~Manager(){
	for(Buffer *buffer : buffers){
		delete buffer;
	}
}

void Manager::receive(const Command &cmd){
	if(cmd[0]=="open_file"){
		buffers.push_back(new Buffer(this));
		buffers.back()->receive(cmd);
		activeIdx=buffers.size()-1;
	} else if(cmd[0]=="open_prompt"){
		Maybe<string> mfname=promptString("open: ");
		if(mfname.isNothing())return;
		buffers.push_back(new Buffer(this));
		buffers.back()->receive({"open_file",mfname.fromJust()});
		activeIdx=buffers.size()-1;
	} else if(cmd[0]=="save_prompt"){
		if(activeIdx==-1){
			receive({"error","No buffers open!"});
			return;
		}
		Maybe<string> mfname=promptString("save: ");
		if(mfname.isNothing())return;
		buffers[activeIdx]->filename=mfname.fromJust();
		buffers[activeIdx]->receive({"save_file"});
	} else if(cmd[0]=="close_tab"){
		if(activeIdx==-1){
			receive({"error","No buffers open!"});
			return;
		}
		if(buffers[activeIdx]->isDirty()){
			char choice=promptChar("Unsaved changes; discard? [y/N]","yn",'n');
			if(choice=='n')return;
		}
		delete buffers[activeIdx];
		buffers.erase(buffers.begin()+activeIdx);
		if(activeIdx>0)activeIdx--;
		if(buffers.size()==0)buffers.push_back(new Buffer(this));
	} else if(cmd[0]=="cycle_tabs"){
		if(activeIdx==-1){
			receive({"error","No buffers open!"});
			return;
		}
		activeIdx=(activeIdx+1)%buffers.size();
	} else if(cmd[0]=="cycle_tabs_back"){
		if(activeIdx==-1){
			receive({"error","No buffers open!"});
			return;
		}
		activeIdx=(activeIdx+buffers.size()-1)%buffers.size();
	} else if(cmd[0]=="error"||cmd[0]=="info"){
		if(!have_screen)return;
		bool isError=cmd[0]=="error";
		pushcursor();
		Size termsize=gettermsize();
		Style style={isError?1:9,9,isError,false};
		fillrect(0,termsize.h-1,termsize.w,1,' ');
		moveto(0,termsize.h-1);
		setstyle(&style);
		tprintf("%s",cmd[1].data());
		popcursor();
	} else if(cmd[0]=="quit_app"){
		Size termsize=gettermsize();
		for(i64 i=0;i<(i64)buffers.size();i++){
			if(!buffers[i]->isDirty())continue;
			activeIdx=i;
			buffers[activeIdx]->show(0,1,termsize.w,termsize.h-2);
			show();
			if(promptChar("Unsaved changes in this buffer; discard? [y/N]","yn",'n')=='n'){
				return;
			}
		}
		should_quit=true;
	} else if(cmd[0]=="display_prompt"){
		Maybe<string> mline=promptString(":");
		if(mline.isJust())receive({"info",{mline.fromJust()}});
	} else {
		if(activeIdx==-1)bel();
		else buffers[activeIdx]->receive(cmd);
	}
}

void Manager::show(){
	if(buffers.size()==0)return;

	string bartext;
	i64 hilight_start=-1,hilight_len;
	for(size_t i=0;i<buffers.size();i++){
		string fname=buffers[i]->filename.size()==0?"<New file>":buffers[i]->filename;
		string tabtext=" ";
		for(size_t j=0;j<fname.size();j++){
			if(fname[j]=='/'){
				tabtext+='/';
				if(j+1<fname.size()){
					tabtext+=fname[j+1];
					j++;
				}
			}
		}

		i64 nameidx;
		for(nameidx=fname.size()-1;nameidx>=0;nameidx--){
			if(fname[nameidx]=='/'){
				nameidx++;
				break;
			}
		}

		//+1 because the first char was already appended
		tabtext+=fname.substr(nameidx+1,string::npos);

		if(buffers[i]->isDirty())tabtext+='*';
		tabtext+=' ';

		if((i64)i==activeIdx){
			hilight_start=bartext.size();
			hilight_len=tabtext.length();
		}
		bartext+=tabtext;
	}

	assert(hilight_start!=-1);

	Size termsize=gettermsize();
	i64 print_start=-1;
	if(bartext.size()<=(size_t)termsize.w){
		print_start=0;
	} else {
		print_start=hilight_start+hilight_len/2-termsize.w/2;
		if(print_start<0){
			print_start=0;
		} else if(print_start+(size_t)termsize.w>=bartext.size()){
			print_start=bartext.size()-termsize.w;
		}
	}

	Style backStyle={7,0,false,false};
	Style activeStyle={7,4,true,false};

	pushcursor();
	moveto(0,0);
	setstyle(&backStyle);
	fillrect(0,0,termsize.w,1,' ');
	if(print_start>=hilight_start+hilight_len||print_start+termsize.w<=hilight_start){
		string text=bartext.substr(print_start,termsize.w);
		tprintf("%s",text.data());
	} else {
		string text=bartext.substr(print_start,hilight_start-print_start);
		tprintf("%s",text.data());

		text=bartext.substr(hilight_start,hilight_len);
		setstyle(&activeStyle);
		tprintf("%s",text.data());

		text=bartext.substr(hilight_start+hilight_len,termsize.w-(hilight_start+hilight_len-print_start));
		setstyle(&backStyle);
		tprintf("%s",text.data());
	}
	popcursor();
}

class TermioRAII{
	bool *variable;

public:
	TermioRAII(bool *variable):variable(variable){
		initscreen();
		initkeyboard(true);
		*variable=true;
	}
	~TermioRAII(){
		*variable=false;
		endkeyboard();
		endscreen();
	}
};

int Manager::io(){
	TermioRAII termioRAII(&have_screen);

	if(activeIdx==-1){
		buffers.push_back(new Buffer(this));
		activeIdx=0;
	}

	while(true){
		Size termsize=gettermsize();
		show();
		buffers[activeIdx]->show(0,1,termsize.w,termsize.h-2);
		redraw();

		int key=tgetkey();
		if(key<0){
			cerr<<"Input read error: key="<<key<<endl;
			key=tgetkey();
			if(key<0){
				cerr<<"Input double read error: key="<<key<<endl;
				break;
			} else {
				receive({"error","Standard input is unreliable!"});
			}
		}

		Either<bool,Command> ret=global_keyinput.input(key);
		if(ret.isLeft()){
			if(!ret.fromLeft()){
				bel();
				receive({"error","Unbound key sequence"});
			}
		} else {
			receive(ret.fromRight());
		}
		if(should_quit)break;
	}

	return 0;
}


string truncatePromptString(const string &promptString,i64 width){
	if((i64)promptString.size()>width*3/4){
		string truncated(promptString.begin(),promptString.begin()+(width*3/4-3));
		return truncated+"...";
	} else {
		return promptString;
	}
}

//Returns entered text, or Nothing if cancelled
Maybe<string> Manager::promptString(const string &promptString){
	Size termsize=gettermsize();
	moveto(0,termsize.h-1);
	string truncated=truncatePromptString(promptString,termsize.w);
	i64 leftX=truncated.size();
	Style promptStyle={9,9,false,false};
	setstyle(&promptStyle);
	tprintf("%s",truncated.data());

	global_keyinput.cancel();

	string inputLine;
	Buffer promptBuffer(this,true);
	while(true){
		termsize=gettermsize();
		promptBuffer.show(leftX,termsize.h-1,termsize.w-leftX,1);
		redraw();

		int key=tgetkey();
		if(key<0){
			cerr<<"Input read error in promptString: key="<<key<<endl;
			fillrect(0,termsize.h-1,termsize.w,1,' ');
			return {};
		}

		Either<bool,Command> ret=global_keyinput.input(key);
		if(ret.isLeft()){
			if(!ret.fromLeft()){
				bel();
			}
		} else {
			Command cmd=ret.fromRight();;
			if(cmd[0]=="insert_newline"){
				termsize=gettermsize();
				fillrect(0,termsize.h-1,termsize.w,1,' ');
				return promptBuffer.getText();
			} else if(cmd[0]=="cancel"){
				termsize=gettermsize();
				fillrect(0,termsize.h-1,termsize.w,1,' ');
				return {};
			} else {
				promptBuffer.receive(cmd);
			}
		}
	}
}

char Manager::promptChar(const string &promptString,const string &options,char def){
	Size termsize=gettermsize();
	moveto(0,termsize.h-1);
	string truncated=truncatePromptString(promptString,termsize.w);
	Style promptStyle={9,9,false,false};
	setstyle(&promptStyle);
	tprintf("%s",truncated.data());
	redraw();

	global_keyinput.cancel();

	while(true){
		int key=tgetkey();
		if(key<0){
			cerr<<"Input read error in promptChar: key="<<key<<endl;
			fillrect(0,termsize.h-1,termsize.w,1,' ');
			return def;
		}
		if(key==KEY_ESC)return def;
		if(key<=0||key>=127){
			bel();
			continue;
		}
		key=tolower(key);
		if(options.find((char)key)!=string::npos){
			termsize=gettermsize();
			fillrect(0,termsize.h-1,termsize.w,1,' ');
			return (char)key;
		}
		bel();
	}
}