/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2014 Olaf Wintermann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>

#include "text.h"
#include "container.h"


UIWIDGET ui_textarea_var(UiObject *obj, UiVar *var) {
    UiContainer *ct = uic_get_current_container(obj);
    int n = 0;
    Arg args[16];
    
    //XtSetArg(args[n], XmNeditable, TRUE);
    //n++;
    XtSetArg(args[n], XmNeditMode, XmMULTI_LINE_EDIT);
    n++;
    
    Widget parent = ct->prepare(ct, args, &n, TRUE);
    Widget text_area = XmCreateScrolledText(parent, "text_area", args, n);
    ct->add(ct, XtParent(text_area));
    XtManageChild(text_area);
    
    UiTextArea *uitext = ucx_mempool_malloc(
            obj->ctx->mempool,
            sizeof(UiTextArea));
    uitext->ctx = obj->ctx;
    uitext->last_selection_state = 0;
    XtAddCallback(
                text_area,
                XmNmotionVerifyCallback,
                (XtCallbackProc)ui_text_selection_callback,
                uitext);
    
    // bind value
    if(var->value) {
        UiText *value = var->value;
        if(value->value.ptr) {
            XmTextSetString(text_area, value->value.ptr);
            value->value.free(value->value.ptr);
        }
        
        value->set = ui_textarea_set;
        value->get = ui_textarea_get;
        value->getsubstr = ui_textarea_getsubstr;
        value->insert = ui_textarea_insert;
        value->setposition = ui_textarea_setposition;
        value->position = ui_textarea_position;
        value->selection = ui_textarea_selection;
        value->length = ui_textarea_length;
        value->value.ptr = NULL;
        value->obj = text_area;
        
        if(!value->undomgr) {
            value->undomgr = ui_create_undomgr();
        }
        
        XtAddCallback(
                text_area,
                XmNmodifyVerifyCallback,
                (XtCallbackProc)ui_text_modify_callback,
                var);
    }
    
    return text_area;
}

UIWIDGET ui_textarea(UiObject *obj, UiText *value) {
    UiVar *var = malloc(sizeof(UiVar));
    var->value = value;
    var->type = UI_VAR_SPECIAL;
    return ui_textarea_var(obj, var);
}

UIWIDGET ui_textarea_nv(UiObject *obj, char *varname) {
    UiVar *var = uic_create_var(obj->ctx, varname, UI_VAR_TEXT);
    if(var) {
        return ui_textarea_var(obj, var);
    } else {
        // TODO: error
    }
    return NULL;
}

char* ui_textarea_get(UiText *text) {
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    char *str = XmTextGetString(text->obj);
    text->value.ptr = str;
    text->value.free = (ui_freefunc)XtFree;
    return str;
}

void ui_textarea_set(UiText *text, char *str) {
    XmTextSetString(text->obj, str);
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    text->value.ptr = NULL;
}

char* ui_textarea_getsubstr(UiText *text, int begin, int end) {
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    int length = end - begin;
    char *str = XtMalloc(length + 1);
    XmTextGetSubstring(text->obj, begin, length, length + 1, str);
    text->value.ptr = str;
    text->value.free = (ui_freefunc)XtFree;
    return str;
}

void ui_textarea_insert(UiText *text, int pos, char *str) {
    text->value.ptr = NULL;
    XmTextInsert(text->obj, pos, str);
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
}

void ui_textarea_setposition(UiText *text, int pos) {
    XmTextSetInsertionPosition(text->obj, pos);
}

int ui_textarea_position(UiText *text) {
    long begin;
    long end;
    XmTextGetSelectionPosition(text->obj, &begin, &end);
    text->pos = begin;
    return text->pos;
}

void ui_textarea_selection(UiText *text, int *begin, int *end) {
    XmTextGetSelectionPosition(text->obj, (long*)begin, (long*)end);
}

int ui_textarea_length(UiText *text) {
    return (int)XmTextGetLastPosition(text->obj);
}


void ui_text_set(UiText *text, char *str) {
    if(text->set) {
        text->set(text, str);
    } else {
        if(text->value.ptr) {
            text->value.free(text->value.ptr);
        }
        text->value.ptr = XtNewString(str);
        text->value.free = (ui_freefunc)XtFree;
    }
}

char* ui_text_get(UiText *text) {
    if(text->get) {
        return text->get(text);
    } else {
        return text->value.ptr;
    }
}


UiUndoMgr* ui_create_undomgr() {
    UiUndoMgr *mgr = malloc(sizeof(UiUndoMgr));
    mgr->begin = NULL;
    mgr->cur = NULL;
    mgr->length = 0;
    mgr->event = 1;
    return mgr;
}

void ui_text_selection_callback(
        Widget widget,
        UiTextArea *textarea,
        XtPointer data)
{
    long left = 0;
    long right = 0;
    XmTextGetSelectionPosition(widget, &left, &right);
    int sel = left < right ? 1 : 0;
    if(sel != textarea->last_selection_state) {
        if(sel) {
            ui_set_group(textarea->ctx, UI_GROUP_SELECTION);
        } else {
            ui_unset_group(textarea->ctx, UI_GROUP_SELECTION);
        }
    }
    textarea->last_selection_state = sel;
}

void ui_text_modify_callback(Widget widget, UiVar *var, XtPointer data) {
    UiText *value = var->value;
    if(!value->obj) {
        // TODO: bug, fix
        return;
    }
    if(!value->undomgr) {
        value->undomgr = ui_create_undomgr();
    }
    
    XmTextVerifyCallbackStruct *txv = (XmTextVerifyCallbackStruct*)data;
    int type = txv->text->length > 0 ? UI_TEXTBUF_INSERT : UI_TEXTBUF_DELETE;
    UiUndoMgr *mgr = value->undomgr;
    if(!mgr->event) {
        return;
    }
    
    char *text = txv->text->ptr;
    int length = txv->text->length;
    
    if(mgr->cur) {
        UcxList *elm = mgr->cur->next;
        if(elm) {
            mgr->cur->next = NULL;
            while(elm) {
                elm->prev = NULL;   
                UcxList *next = elm->next;
                ui_free_textbuf_op(elm->data);
                free(elm);
                elm = next;
            }
        }
        
        if(type == UI_TEXTBUF_INSERT) {
            UiTextBufOp *last_op = mgr->cur->data;
            if(
                last_op->type == UI_TEXTBUF_INSERT &&
                ui_check_insertstr(last_op->text, last_op->len, text, length) == 0)
            {
                // append text to last op
                int ln = last_op->len;
                char *newtext = malloc(ln + length + 1);
                memcpy(newtext, last_op->text, ln);
                memcpy(newtext+ln, text, length);
                newtext[ln+length] = '\0';
                
                last_op->text = newtext;
                last_op->len = ln + length;
                last_op->end += length;

                return;
            }
        }
    }
    
    char *str;
    if(type == UI_TEXTBUF_INSERT) {
        str = malloc(length + 1);
        memcpy(str, text, length);
        str[length] = 0;
    } else {
        length = txv->endPos - txv->startPos;
        str = malloc(length + 1);
        XmTextGetSubstring(value->obj, txv->startPos, length, length+1, str);
    }
    
    UiTextBufOp *op = malloc(sizeof(UiTextBufOp));
    op->type = type;
    op->start = txv->startPos;
    op->end = txv->endPos + 1;
    op->len = length;
    op->text = str;
    
    UcxList *elm = ucx_list_append(NULL, op);
    mgr->cur = elm;
    mgr->begin = ucx_list_concat(mgr->begin, elm);
}

int ui_check_insertstr(char *oldstr, int oldlen, char *newstr, int newlen) {
    // return 1 if oldstr + newstr are one word
    
    int has_space = 0;
    for(int i=0;i<oldlen;i++) {
        if(oldstr[i] < 33) {
            has_space = 1;
            break;
        }
    }
    
    for(int i=0;i<newlen;i++) {
        if(has_space && newstr[i] > 32) {
            return 1;
        }
    }
    
    return 0;
}

void ui_free_textbuf_op(UiTextBufOp *op) {
    if(op->text) {
        free(op->text);
    }
    free(op);
}


void ui_text_undo(UiText *value) {
    UiUndoMgr *mgr = value->undomgr;
    
    if(mgr->cur) {
        UiTextBufOp *op = mgr->cur->data;
        mgr->event = 0;
        switch(op->type) {
            case UI_TEXTBUF_INSERT: {
                XmTextReplace(value->obj, op->start, op->end, "");
                break;
            }
            case UI_TEXTBUF_DELETE: {
                XmTextInsert(value->obj, op->start, op->text);
                break;
            }
        }
        mgr->event = 1;
        mgr->cur = mgr->cur->prev;
    }
}

void ui_text_redo(UiText *value) {
    UiUndoMgr *mgr = value->undomgr;
    
    UcxList *elm = NULL;
    if(mgr->cur) {
        if(mgr->cur->next) {
            elm = mgr->cur->next;
        }
    } else if(mgr->begin) {
        elm = mgr->begin;
    }
    
    if(elm) {
        UiTextBufOp *op = elm->data;
        mgr->event = 0;
        switch(op->type) {
            case UI_TEXTBUF_INSERT: {
                XmTextInsert(value->obj, op->start, op->text);
                break;
            }
            case UI_TEXTBUF_DELETE: {
                XmTextReplace(value->obj, op->start, op->end, "");
                break;
            }
        }
        mgr->event = 1;
        mgr->cur = elm;
    }
}


/* ------------------------- textfield ------------------------- */

static UIWIDGET create_textfield(UiObject *obj, int width, UiBool frameless, UiBool password, UiString *value) {
    UiContainer *ct = uic_get_current_container(obj);
    int n = 0;
    Arg args[16];
    XtSetArg(args[n], XmNeditMode, XmSINGLE_LINE_EDIT);
    n++;
    if(width > 0) {
        XtSetArg(args[n], XmNcolumns, width / 2 + 1);
        n++;
    }
    if(frameless) {
        XtSetArg(args[n], XmNshadowThickness, 0);
        n++;
    }
    if(password) {
        // TODO
    }
    
    Widget parent = ct->prepare(ct, args, &n, FALSE);
    Widget textfield = XmCreateText(parent, "text_field", args, n);
    ct->add(ct, textfield);
    XtManageChild(textfield);
    
    // bind value
    if(value) {
        if(value->value.ptr) {
            XmTextSetString(textfield, value->value.ptr);
            value->value.free(value->value.ptr);
        }
        
        value->set = ui_textfield_set;
        value->get = ui_textfield_get;
        value->value.ptr = NULL;
        value->obj = textfield;
    }
    
    return textfield;
}

static UIWIDGET create_textfield_nv(UiObject *obj, int width, UiBool frameless, UiBool password, char *varname) {
    UiVar *var = uic_create_var(obj->ctx, varname, UI_VAR_STRING);
    if(var) {
        UiString *value = var->value;
        return ui_textfield(obj, value);
    } else {
        // TODO: error
    }
    return NULL;
}

UIWIDGET ui_textfield(UiObject *obj, UiString *value) {
    return create_textfield(obj, 0, FALSE, FALSE, value);
}

UIWIDGET ui_textfield_nv(UiObject *obj, char *varname) {
    return create_textfield_nv(obj, 0, FALSE, FALSE, varname);
}

UIWIDGET ui_textfield_w(UiObject *obj, int width, UiString *value) {
    return create_textfield(obj, width, FALSE, FALSE, value);
}

UIWIDGET ui_textfield_wnv(UiObject *obj, int width, char *varname) {
    return create_textfield_nv(obj, width, FALSE, FALSE, varname);
}

UIWIDGET ui_frameless_textfield(UiObject *obj, UiString *value) {
    return create_textfield(obj, 0, TRUE, FALSE, value);
}

UIWIDGET ui_frameless_textfield_nv(UiObject *obj, char *varname) {
    return create_textfield_nv(obj, 0, TRUE, FALSE, varname);
}

UIWIDGET ui_passwordfield(UiObject *obj, UiString *value) {
    return create_textfield(obj, 0, FALSE, TRUE, value);
}

UIWIDGET ui_passwordfield_nv(UiObject *obj, char *varname) {
    return create_textfield_nv(obj, 0, FALSE, TRUE, varname);
}

UIWIDGET ui_passwordfield_w(UiObject *obj, int width, UiString *value) {
    return create_textfield(obj, width, FALSE, TRUE, value);
}

UIWIDGET ui_passwordfield_wnv(UiObject *obj, int width, char *varname) {
    return create_textfield_nv(obj, width, FALSE, TRUE, varname);
}


char* ui_textfield_get(UiString *str) {
    if(str->value.ptr) {
        str->value.free(str->value.ptr);
    }
    char *value = XmTextGetString(str->obj);
    str->value.ptr = value;
    str->value.free = (ui_freefunc)XtFree;
    return value;
}

void ui_textfield_set(UiString *str, char *value) {
    XmTextSetString(str->obj, value);
    if(str->value.ptr) {
        str->value.free(str->value.ptr);
    }
    str->value.ptr = NULL;
}