module dlangide.tools.d.deditortool;

import dlangide.tools.editortool;
import dlangide.tools.d.dcdinterface;
import dlangide.ui.dsourceedit;
import dlangui.widgets.editors;
import dlangide.ui.frame;
import std.stdio;
import std..string;
import std.utf;
import dlangui.core.logger;

import std.conv;

// TODO: async operation in background thread
// TODO: effective caretPositionToByteOffset/byteOffsetToCaret impl

class DEditorTool : EditorTool 
{
    this(IDEFrame frame) {
        super(frame);
    }

    ~this() {
        cancelGoToDefinition();
        cancelGetDocComments();
        cancelGetCompletions();
    }

    static bool isIdentChar(char ch) {
        return ch == '_' || (ch >= 'a' && ch <='z') || (ch >= 'A' && ch <='Z') || ((ch & 0x80) != 0);
    }
    static bool isAtWord(string content, size_t byteOffset) {
        if (byteOffset >= content.length)
            return false;
        if (isIdentChar(content[byteOffset]))
            return true;
        if (byteOffset > 0 && isIdentChar(content[byteOffset - 1]))
            return true;
        if (byteOffset + 1 < content.length && isIdentChar(content[byteOffset + 1]))
            return true;
        return false;
    }

    DCDTask _getDocCommentsTask;
    override void getDocComments(DSourceEdit editor, TextPosition caretPosition, void delegate(string[]) callback) {
        cancelGetDocComments();
        string[] importPaths = editor.importPaths(_frame.settings);
        string content = toUTF8(editor.text);
        auto byteOffset = caretPositionToByteOffset(content, caretPosition);
        if (!isAtWord(content, byteOffset))
            return;
        _getDocCommentsTask = _frame.dcdInterface.getDocComments(editor.window, importPaths, editor.filename, content, byteOffset, delegate(DocCommentsResultSet output) {
            if(output.result == DCDResult.SUCCESS) {
                auto doc = output.docComments;
                Log.d("Doc comments: ", doc);
                if (doc.length)
                    callback(doc);
                _getDocCommentsTask = null;
            }
        });
    }

    override void cancelGetDocComments() {
        if (_getDocCommentsTask) {
            Log.d("Cancelling getDocComments()");
            _getDocCommentsTask.cancel();
            _getDocCommentsTask = null;
        }
    }

    override void cancelGoToDefinition() {
        if (_goToDefinitionTask) {
            Log.d("Cancelling goToDefinition()");
            _goToDefinitionTask.cancel();
            _goToDefinitionTask = null;
        }
    }

    override void cancelGetCompletions() {
        if (_getCompletionsTask) {
            Log.d("Cancelling getCompletions()");
            _getCompletionsTask.cancel();
            _getCompletionsTask = null;
        }
    }

    DCDTask _goToDefinitionTask;
    override void goToDefinition(DSourceEdit editor, TextPosition caretPosition) {
        cancelGoToDefinition();
        string[] importPaths = editor.importPaths(_frame.settings);
        string content = toUTF8(editor.text);
        auto byteOffset = caretPositionToByteOffset(content, caretPosition);


        _goToDefinitionTask = _frame.dcdInterface.goToDefinition(editor.window, importPaths, editor.filename, content, byteOffset, delegate(FindDeclarationResultSet output) {
            // handle result
            switch(output.result) {
                //TODO: Show dialog
                case DCDResult.FAIL:
                case DCDResult.NO_RESULT:
                    editor.setFocus();
                    break;
                case DCDResult.SUCCESS:
                    auto fileName = output.fileName;
                    if(fileName.indexOf("stdin") == 0) {
                        Log.d("Declaration is in current file. Jumping to it.");
                    } else {
                        //Must open file first to get the content for finding the correct caret position.
                        if (!_frame.openSourceFile(to!string(fileName)))
                            break;
                        if (_frame.currentEditor.parent)
                            _frame.currentEditor.parent.layout(_frame.currentEditor.parent.pos);
                        content = toUTF8(_frame.currentEditor.text);
                    }
                    auto target = to!int(output.offset);
                    auto destPos = byteOffsetToCaret(content, target);
                    _frame.currentEditor.setCaretPos(destPos.line,destPos.pos, true, true);
                    _frame.currentEditor.setFocus();
                    _frame.caretHistory.pushNewPosition();
                    break;
                default:
                    break;
            }
            _goToDefinitionTask = null;
        });

    }

    DCDTask _getCompletionsTask;
    override void getCompletions(DSourceEdit editor, TextPosition caretPosition, void delegate(dstring[] completions, string[] icons, CompletionTypes type) callback) {
        cancelGetCompletions();
        string[] importPaths = editor.importPaths(_frame.settings);

        string content = toUTF8(editor.text);
        auto byteOffset = caretPositionToByteOffset(content, caretPosition);
        _getCompletionsTask = _frame.dcdInterface.getCompletions(editor.window, importPaths, editor.filename, content, byteOffset, delegate(CompletionResultSet output) {
            string[] icons;
            dstring[] labels;
            foreach(index, label; output.output) {
                string iconId;
                char ch = label.kind;
                switch(ch) {
                    case 'c': // - class name
                        iconId = "symbol-class";
                        break;
                    case 'i': // - interface name
                        iconId = "symbol-interface";
                        break;
                    case 's': // - struct name
                        iconId = "symbol-struct";
                        break;
                    case 'u': // - union name
                        iconId = "symbol-union";
                        break;
                    case 'v': // - variable name
                        iconId = "symbol-var";
                        break;
                    case 'm': // - member variable name
                        iconId = "symbol-membervar";
                        break;
                    case 'k': // - keyword, built-in version, scope statement
                        iconId = "symbol-keyword";
                        break;
                    case 'f': // - function or method
                        iconId = "symbol-function";
                        break;
                    case 'g': // - enum name
                        iconId = "symbol-enum";
                        break;
                    case 'e': // - enum member
                        iconId = "symbol-enum";
                        break;
                    case 'P': // - package name
                        iconId = "symbol-package";
                        break;
                    case 'M': // - module name
                        iconId = "symbol-module";
                        break;
                    case 'a': // - array
                        iconId = "symbol-array";
                        break;
                    case 'A': // - associative array
                        iconId = "symbol-array";
                        break;
                    case 'l': // - alias name
                        iconId = "symbol-alias";
                        break;
                    case 't': // - template name
                        iconId = "symbol-template";
                        break;
                    case 'T': // - mixin template name
                        iconId = "symbol-mixintemplate";
                        break;
                    default:
                        iconId = "symbol-other";
                        break;
                }
                icons ~= iconId;
                labels ~= label.name;
            }
            callback(labels, icons, output.type);
            _getCompletionsTask = null;
        });
    }

private:

}

/// convert caret position to byte offset in utf8 content
int caretPositionToByteOffset(string content, TextPosition caretPosition) {
    auto line = 0;
    auto pos = 0;
    auto bytes = 0;
    foreach(c; content) {
        if(line == caretPosition.line) {
            if(pos >= caretPosition.pos)
                break;
            if ((c & 0xC0) != 0x80)
                pos++;
        } else if (line > caretPosition.line) {
            break;
        }
        bytes++;
        if(c == '\n') {
            line++;
            pos = 0;
        }
    }
    return bytes;
}

/// convert byte offset in utf8 content to caret position
TextPosition byteOffsetToCaret(string content, int byteOffset) {
    int bytes = 0;
    int line = 0;
    int pos = 0;
    TextPosition textPos;
    foreach(c; content) {
        if(bytes >= byteOffset) {
            //We all good.
            textPos.line = line;
            textPos.pos = pos;
            return textPos;
        }
        bytes++;
        if(c == '\n')
        {
            line++;
            pos = 0;
        }
        else {
            if ((c & 0xC0) != 0x80)
                pos++;
        }
    }
    return textPos;
}