module dlangide.tools.d.dcdinterface;

import dlangui.core.logger;
import dlangui.core.files;

import dlangide.builders.extprocess;

import std.typecons;
import std.conv;
import std..string;

const DCD_SERVER_PORT_FOR_DLANGIDE = 9167;
const DCD_DEFAULT_PORT = 9166;

enum DCDResult : int {
	DCD_NOT_RUNNING = 0,
	SUCCESS,
	NO_RESULT,
	FAIL,
}
alias ResultSet = Tuple!(DCDResult, "result", dstring[], "output");


//Interface to DCD
//TODO: Check if server is running, start server if needed etc.
class DCDInterface {

    private int _port;
    //ExternalProcess dcdProcess;
    //ProtectedTextStorage stdoutTarget;
	this(int port = DCD_SERVER_PORT_FOR_DLANGIDE) {
        _port = port;
        //dcdProcess = new ExternalProcess();
        //stdoutTarget = new ProtectedTextStorage();
	}

    protected string dumpContext(string content, int pos) {
        if (pos >= 0 && pos <= content.length) {
            int start = pos;
            int end = pos;
            for (int i = 0; start > 0 && content[start - 1] != '\n' && i < 10; i++)
                start--;
            for (int i = 0; end < content.length - 1 && content[end] != '\n' && i < 10; i++)
                end++;
            return content[start .. pos] ~ "|" ~ content[pos .. end];
        }
        return "";
    }

    protected dstring[] invokeDcd(string[] arguments, string content, out bool success) {
        success = false;
		ExternalProcess dcdProcess = new ExternalProcess();

		ProtectedTextStorage stdoutTarget = new ProtectedTextStorage();

		version(Windows) {
			string dcd_client_name = "dcd-client.exe";
			string dcd_client_dir = null;
		} else {
			string dcd_client_name = "dcd-client";
			string dcd_client_dir = "/usr/bin";
		}
		dcdProcess.run(dcd_client_name, arguments, dcd_client_dir, stdoutTarget);
        
		dcdProcess.write(content);
		dcdProcess.wait();

		dstring[] output =  stdoutTarget.readText.splitLines();

		if(dcdProcess.poll() == ExternalProcessState.Stopped) {
			success = true;
		}
        return output;
    }

	ResultSet goToDefinition(in string[] importPaths, in string content, int index) {
		ResultSet result;
        
        debug(DCD) Log.d("DCD Context: ", dumpContext(content, index));

		string[] arguments = ["-l", "-c"];
		arguments ~= [to!string(index)];

        foreach(p; importPaths) {
            arguments ~= "-I" ~ p;
        }
        if (_port != DCD_DEFAULT_PORT)
            arguments ~= "-p" ~ to!string(_port);

        bool success = false;
		dstring[] output =  invokeDcd(arguments, content, success);

		if (success) {
			result.result = DCDResult.SUCCESS;
		} else {
			result.result = DCDResult.FAIL;
			return result;
		}

        debug(DCD) Log.d("DCD output:\n", output);

		if(output.length > 0) {
            dstring firstLine = output[0];
			if(firstLine.startsWith("Not Found") || firstLine.startsWith("Not found")) {
				result.result = DCDResult.NO_RESULT;
				return result;
			}
            auto split = firstLine.indexOf("\t");
            if(split == -1) {
                Log.d("DCD output format error.");
                result.result = DCDResult.FAIL;
                return result;
            }

            result.output ~= output[0][0 .. split];
            result.output ~= output[0][split+1 .. $];
		} else {
            result.result = DCDResult.NO_RESULT;
            //result.result = DCDResult.FAIL;
        }

		return result;
	}

	ResultSet getCompletions(in string[] importPaths, in string content, int index) {

        debug(DCD) Log.d("DCD Context: ", dumpContext(content, index));

		ResultSet result;

		string[] arguments = ["-c"];
		arguments ~= [to!string(index)];

        foreach(p; importPaths) {
            arguments ~= "-I" ~ p;
        }
        if (_port != DCD_DEFAULT_PORT)
            arguments ~= "-p" ~ to!string(_port);

        bool success = false;
		dstring[] output =  invokeDcd(arguments, content, success);

		if (success) {
			result.result = DCDResult.SUCCESS;
		} else {
			result.result = DCDResult.FAIL;
			return result;
		}
        debug(DCD) Log.d("DCD output:\n", output);

		if (output.length == 0) {
			result.result = DCDResult.NO_RESULT;
			return result;
		}

		enum State : int {None = 0, Identifiers, Calltips}
		State state = State.None;
		foreach(dstring outputLine ; output) {
			if(outputLine == "identifiers") {
				state = State.Identifiers;
			}
			else if(outputLine == "calltips") {
				state = State.Calltips;
			}
			else {
				auto split = outputLine.indexOf("\t");
				if(split < 0) {
					break;
				}
				if(state == State.Identifiers) {
					result.output ~= outputLine[0 .. split];
				}
			}
		}
		return result;
	}
}