/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright 2017 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 <string.h>

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


static void selection_handler(
        GtkTextBuffer *buf,
        GtkTextIter *location,
        GtkTextMark *mark,
        UiTextArea *textview)
{
    const char *mname = gtk_text_mark_get_name(mark);
    if(mname) {
        GtkTextIter begin;
        GtkTextIter end;
        int sel = gtk_text_buffer_get_selection_bounds (buf, &begin, &end);
        if(sel != textview->last_selection_state) {
            if(sel) {
                ui_set_group(textview->ctx, UI_GROUP_SELECTION);
            } else {
                ui_unset_group(textview->ctx, UI_GROUP_SELECTION);
            }
        }
        textview->last_selection_state = sel;
    }
}

UIWIDGET ui_textarea_var(UiObject *obj, UiVar *var) {
    GtkWidget *text_area = gtk_text_view_new();
    gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(text_area), GTK_WRAP_WORD_CHAR);
    g_signal_connect(
            text_area,
            "realize",
            G_CALLBACK(ui_textarea_realize_event),
            NULL);
    
    UiTextArea *uitext = malloc(sizeof(UiTextArea));
    uitext->ctx = obj->ctx;
    uitext->var = var;
    uitext->last_selection_state = 0;
    
    g_signal_connect(
                text_area,
                "destroy",
                G_CALLBACK(ui_textarea_destroy),
                uitext);
    
    GtkWidget *scroll_area = gtk_scrolled_window_new (NULL, NULL);
    gtk_scrolled_window_set_policy(
            GTK_SCROLLED_WINDOW(scroll_area),
            GTK_POLICY_AUTOMATIC,
            GTK_POLICY_AUTOMATIC); // GTK_POLICY_ALWAYS  
    gtk_container_add(GTK_CONTAINER(scroll_area), text_area);
    
    // font and padding
    PangoFontDescription *font;
    font = pango_font_description_from_string("Monospace");
    gtk_widget_modify_font(text_area, font);
    pango_font_description_free(font);
    
    gtk_text_view_set_left_margin(GTK_TEXT_VIEW(text_area), 2);
    gtk_text_view_set_right_margin(GTK_TEXT_VIEW(text_area), 2);
    
    // add
    UiContainer *ct = uic_get_current_container(obj);
    ct->add(ct, scroll_area, TRUE);
    
    // bind value
    UiText *value = var->value;
    if(value) {
        GtkTextBuffer *buf = gtk_text_view_get_buffer(GTK_TEXT_VIEW(text_area));
        
        if(value->value.ptr) {
            gtk_text_buffer_set_text(buf, value->value.ptr, -1);
            value->value.free(value->value.ptr);
        }
        
        value->get = ui_textarea_get;
        value->set = ui_textarea_set;
        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->remove = ui_textarea_remove;
        value->value.ptr = NULL;
        value->value.free = NULL;
        value->obj = buf;
        if(!value->undomgr) {
            value->undomgr = ui_create_undomgr();
        }
        
        g_signal_connect(
                buf,
                "changed",
                G_CALLBACK(ui_textbuf_changed),
                uitext);
        
        // register undo manager
        g_signal_connect(
                buf,
                "insert-text",
                G_CALLBACK(ui_textbuf_insert),
                var);
        g_signal_connect(
                buf,
                "delete-range",
                G_CALLBACK(ui_textbuf_delete),
                var); 
        g_signal_connect(
                buf,
                "mark-set",
                G_CALLBACK(selection_handler),
                uitext);
    }
    
    return scroll_area;
}

void ui_textarea_destroy(GtkWidget *object, UiTextArea *textarea) {
    ui_destroy_boundvar(textarea->ctx, textarea->var);
    free(textarea);
}

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

UIWIDGET ui_textarea_gettextwidget(UIWIDGET textarea) {
    return gtk_bin_get_child(GTK_BIN(textarea));
}

char* ui_textarea_get(UiText *text) {
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    GtkTextBuffer *buf = text->obj;
    GtkTextIter start;
    GtkTextIter end;
    gtk_text_buffer_get_bounds(buf, &start, &end);
    char *str = gtk_text_buffer_get_text(buf, &start, &end, FALSE);
    text->value.ptr = g_strdup(str);
    text->value.free = (ui_freefunc)g_free;
    return str;
}

void ui_textarea_set(UiText *text, char *str) {
    gtk_text_buffer_set_text((GtkTextBuffer*)text->obj, str, -1);
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    text->value.ptr = NULL;
    text->value.free = NULL;
}

char* ui_textarea_getsubstr(UiText *text, int begin, int end) {
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    GtkTextBuffer *buf = text->obj;
    GtkTextIter ib;
    GtkTextIter ie;
    gtk_text_buffer_get_iter_at_offset(text->obj, &ib, begin);
    gtk_text_buffer_get_iter_at_offset(text->obj, &ie, end);
    char *str = gtk_text_buffer_get_text(buf, &ib, &ie, FALSE);
    text->value.ptr = g_strdup(str);
    text->value.free = (ui_freefunc)g_free;
    return str;
}

void ui_textarea_insert(UiText *text, int pos, char *str) {
    GtkTextIter offset;
    gtk_text_buffer_get_iter_at_offset(text->obj, &offset, pos);
    gtk_text_buffer_insert(text->obj, &offset, str, -1);
    if(text->value.ptr) {
        text->value.free(text->value.ptr);
    }
    text->value.ptr = NULL;
    text->value.free = NULL;
}

void ui_textarea_setposition(UiText *text, int pos) {
    GtkTextIter iter;
    gtk_text_buffer_get_iter_at_offset(text->obj, &iter, pos);
    gtk_text_buffer_place_cursor(text->obj, &iter);
}

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

void ui_textarea_selection(UiText *text, int *begin, int *end) {
    GtkTextIter b;
    GtkTextIter e;
    gtk_text_buffer_get_selection_bounds(text->obj, &b, &e);
    *begin = gtk_text_iter_get_offset(&b);
    *end = gtk_text_iter_get_offset(&e);
}

int ui_textarea_length(UiText *text) {
    GtkTextBuffer *buf = text->obj;
    GtkTextIter start;
    GtkTextIter end;
    gtk_text_buffer_get_bounds(buf, &start, &end);
    return gtk_text_iter_get_offset(&end);
}

void ui_textarea_remove(UiText *text, int begin, int end) {
    GtkTextBuffer *buf = text->obj;
    GtkTextIter ib;
    GtkTextIter ie;
    gtk_text_buffer_get_iter_at_offset(buf, &ib, begin);
    gtk_text_buffer_get_iter_at_offset(buf, &ie, end);
    gtk_text_buffer_delete(buf, &ib, &ie);
}

void ui_textarea_realize_event(GtkWidget *widget, gpointer data) {
    gtk_widget_grab_focus(widget);
}



void ui_textbuf_changed(GtkTextBuffer *textbuffer, UiTextArea *textarea) {
    UiText *value = textarea->var->value;
    if(value->observers) {
        UiEvent e;
        e.obj = textarea->ctx->obj;
        e.window = e.obj->window;
        e.document = textarea->ctx->document;
        e.eventdata = value;
        e.intval = 0;
        ui_notify_evt(value->observers, &e);
    }
}

// undo manager functions

void ui_textbuf_insert(
        GtkTextBuffer *textbuffer,
        GtkTextIter *location,
        char *text,
        int length,
        void *data)
{
    UiVar *var = data;
    UiText *value = var->value;
    if(!value->undomgr) {
        value->undomgr = ui_create_undomgr();
    }
    UiUndoMgr *mgr = value->undomgr;
    if(!mgr->event) {
        return;
    }
    
    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;
            }
        }
        
        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 *dpstr = malloc(length + 1);
    memcpy(dpstr, text, length);
    dpstr[length] = 0;
    
    UiTextBufOp *op = malloc(sizeof(UiTextBufOp));
    op->type = UI_TEXTBUF_INSERT;
    op->start = gtk_text_iter_get_offset(location);
    op->end = op->start+length;
    op->len = length;
    op->text = dpstr;
    
    UcxList *elm = ucx_list_append(NULL, op);
    mgr->cur = elm;
    mgr->begin = ucx_list_concat(mgr->begin, elm);
}

void ui_textbuf_delete(
        GtkTextBuffer *textbuffer,
        GtkTextIter *start,
        GtkTextIter *end,
        void *data)
{
    UiVar *var = data;
    UiText *value = var->value;
    if(!value->undomgr) {
        value->undomgr = ui_create_undomgr();
    }
    UiUndoMgr *mgr = value->undomgr;
    if(!mgr->event) {
        return;
    }
    
    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;
            }
        }
    }
    
    char *text = gtk_text_buffer_get_text(value->obj, start, end, FALSE);
    
    UiTextBufOp *op = malloc(sizeof(UiTextBufOp));
    op->type = UI_TEXTBUF_DELETE;
    op->start = gtk_text_iter_get_offset(start);
    op->end = gtk_text_iter_get_offset(end);
    op->len = op->end - op->start;
    
    char *dpstr = malloc(op->len + 1);
    memcpy(dpstr, text, op->len);
    dpstr[op->len] = 0;
    op->text = dpstr;
    
    UcxList *elm = ucx_list_append(NULL, op);
    mgr->cur = elm;
    mgr->begin = ucx_list_concat(mgr->begin, elm);
}

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

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_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: {
                GtkTextIter begin;
                GtkTextIter end;
                gtk_text_buffer_get_iter_at_offset(value->obj, &begin, op->start);
                gtk_text_buffer_get_iter_at_offset(value->obj, &end, op->end);
                gtk_text_buffer_delete(value->obj, &begin, &end);
                break;
            }
            case UI_TEXTBUF_DELETE: {
                GtkTextIter begin;
                GtkTextIter end;
                gtk_text_buffer_get_iter_at_offset(value->obj, &begin, op->start);
                gtk_text_buffer_get_iter_at_offset(value->obj, &end, op->end);
                gtk_text_buffer_insert(value->obj, &begin, op->text, op->len);
                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: {
                GtkTextIter begin;
                GtkTextIter end;
                gtk_text_buffer_get_iter_at_offset(value->obj, &begin, op->start);
                gtk_text_buffer_get_iter_at_offset(value->obj, &end, op->end);
                gtk_text_buffer_insert(value->obj, &begin, op->text, op->len);
                break;
            }
            case UI_TEXTBUF_DELETE: {
                GtkTextIter begin;
                GtkTextIter end;
                gtk_text_buffer_get_iter_at_offset(value->obj, &begin, op->start);
                gtk_text_buffer_get_iter_at_offset(value->obj, &end, op->end);
                gtk_text_buffer_delete(value->obj, &begin, &end);
                break;
            }
        }
        mgr->event = 1;
        mgr->cur = elm;
    }
}


static UIWIDGET create_textfield_var(UiObject *obj, int width, UiBool frameless, UiBool password, UiVar *var) {
    GtkWidget *textfield = gtk_entry_new();
    
    UiTextField *uitext = malloc(sizeof(UiTextField));
    uitext->ctx = obj->ctx;
    uitext->var = var;
    
    g_signal_connect(
                textfield,
                "destroy",
                G_CALLBACK(ui_textfield_destroy),
                uitext);
    
    if(width > 0) {
        gtk_entry_set_width_chars(GTK_ENTRY(textfield), width);
    }
    if(frameless) {
        // TODO: gtk2legacy workaroud
        gtk_entry_set_has_frame(GTK_ENTRY(textfield), FALSE);
    }
    if(password) {
        gtk_entry_set_visibility(GTK_ENTRY(textfield), FALSE);
    }
    
    UiContainer *ct = uic_get_current_container(obj);
    ct->add(ct, textfield, FALSE);
    
    if(var) {
        UiString *value = var->value;
        if(value->value.ptr) {
            gtk_entry_set_text(GTK_ENTRY(textfield), value->value.ptr);
            value->value.free(value->value.ptr);
            value->value.ptr = NULL;
            value->value.free = NULL;
        }
        
        value->get = ui_textfield_get;
        value->set = ui_textfield_set;
        value->value.ptr = NULL;
        value->value.free = NULL;
        value->obj = GTK_ENTRY(textfield);
        
        g_signal_connect(
                textfield,
                "changed",
                G_CALLBACK(ui_textfield_changed),
                uitext);
    }
    
    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) {
        return create_textfield_var(obj, width, frameless, password, var);
    } else {
        // TODO: error
    }
    return NULL;
}

static UIWIDGET create_textfield(UiObject *obj, int width, UiBool frameless, UiBool password, UiString *value) {
    UiVar *var = NULL;
    if(value) {
        var = malloc(sizeof(UiVar));
        var->value = value;
        var->type = UI_VAR_SPECIAL;
        var->from = NULL;
        var->from_ctx = NULL;
    }
    return create_textfield_var(obj, width, frameless, password, var);
}

void ui_textfield_destroy(GtkWidget *object, UiTextField *textfield) {
    if(textfield->var) {
        ui_destroy_boundvar(textfield->ctx, textfield->var);
    }
    free(textfield);
}

void ui_textfield_changed(GtkEditable *editable, UiTextField *textfield) {
    UiString *value = textfield->var->value;
    if(value->observers) {
        UiEvent e;
        e.obj = textfield->ctx->obj;
        e.window = e.obj->window;
        e.document = textfield->ctx->document;
        e.eventdata = value;
        e.intval = 0;
        ui_notify_evt(value->observers, &e);
    }
}

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);
    }
    str->value.ptr = g_strdup(gtk_entry_get_text(str->obj));
    str->value.free = (ui_freefunc)g_free;
    return str->value.ptr;
}

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