/*
 * Copyright 2022 Olaf Wintermann
 *
 * Permission is hereby granted, free of charge, to any person obtaining a 
 * copy of this software and associated documentation files (the "Software"), 
 * to deal in the Software without restriction, including without limitation 
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 
 * and/or sell copies of the Software, and to permit persons to whom the 
 * Software is furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
 * DEALINGS IN THE SOFTWARE.
 */

#include "settings.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <pthread.h>

#include <sys/socket.h>
#include <sys/un.h>


#include "main.h"
#include "utils.h"
#include "json.h"
#include "window.h"
#include "playlist.h"

#include <cx/map.h>
#include <cx/hash_map.h>
//include <ucx/properties.h>
#include <cx/buffer.h>
#include <cx/utils.h>
#include <cx/printf.h>

#define CONFIG_BASE_DIR ".config"
#define UWP_CONFIG_DIR  "uwplayer"
#define UWP_CONFIG_FILE "uwplayer.conf"

#define JS_READ_BUFSIZE 4096

static void* player_bin_search_thread(void *data);
static void conf_load_global_settings(void);

static char *uwp_config_dir;

static int instance_socket = -1;

/*
 * root json config object
 */
static JSONObject *uwp_config;

/*
 * global settings from json config converted to key/value pairs
 */
static CxMap *uwp_settings; 

/*
 * default settings
 */
static CxMap *uwp_default;

static int check_config_dir(void) {
    char *home = getenv("HOME");
    if(!home) {
        return 1;
    }
    
    char *cfg_dir = util_concat_path(home, CONFIG_BASE_DIR);
    int ret = 0;
    if(mkdir(cfg_dir, S_IRWXU)) {
        if(errno != EEXIST) {
            fprintf(stderr, "Error: Cannot access %s: %s\n", cfg_dir, strerror(errno));
            ret = 1;
        }
    }
    
    if(!ret) {
        uwp_config_dir = util_concat_path(cfg_dir, UWP_CONFIG_DIR);
        if(mkdir(uwp_config_dir, S_IRWXU)) {
            if(errno != EEXIST) {
                fprintf(stderr, "Error: Cannot access %s: %s\n", uwp_config_dir, strerror(errno));
                ret = 1;
            }
        }
    }
    
    free(cfg_dir);
    return ret;
}

int load_config(void) {
    if(check_config_dir()) {
        return 1;
    }
    
    uwp_settings = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 16);
    uwp_default = cxHashMapCreate(cxDefaultAllocator, CX_STORE_POINTERS, 32);
    
    char *cfgfile_path = util_concat_path(uwp_config_dir, UWP_CONFIG_FILE);
    FILE *cfgfile = fopen(cfgfile_path, "r");
    free(cfgfile_path);
    
    int ret = 0;
    if(cfgfile) {
        JSONParser *parser = json_parser_new();
        
        JSONValue *value = NULL;
        char buf[JS_READ_BUFSIZE];
        size_t r;
        
        while((ret = json_read_value(parser, &value)) >= 0) {
            if(ret == 0) {
                r = fread(buf, 1, JS_READ_BUFSIZE, cfgfile);
                if(r == 0) {
                    break;
                }
                json_parser_fill(parser, buf, r);
            } else {
                break;
            }
        }
        
        json_parser_free(parser);
        
        if(value) {
            if(value->type == JSON_OBJECT) {
                ret = 0;
                uwp_config = &value->value.object;
                conf_load_global_settings();
            } else {
                ret = 1;
            }
        } else {
            ret = 1;
        }
        
        
        fclose(cfgfile);

        if(ret) {
            return ret;
        }
    }
 
    
    // check if mpv or mplayer binaries are configured
    char *player_bin = cxMapGet(uwp_settings, cx_hash_key_str(UWP_PLAYER_BIN));
    char *player_type = cxMapGet(uwp_settings, cx_hash_key_str(UWP_PLAYER_TYPE));
    
    if(!player_bin) {
        // try to find the mpv or mplayer binary path
        pthread_t st;
        pthread_create(&st, NULL, player_bin_search_thread, NULL);
    } else if(!player_type) {
        fprintf(stderr, "Warning: unknown player type (mplayer, mpv)\n");
    }
    
    return 0;
}

static void conf_load_global_settings(void) {
    JSONValue *settings = json_obj_get(uwp_config, "settings");
    if(!settings) {
        return;
    }
    
    if(settings->type != JSON_OBJECT) {
        fprintf(stderr, "Warning: 'settings' not an object\n");
        return;
    }
    
    JSONObject *s = &settings->value.object;
    
    for(size_t i=0;i<s->size;i++) {
        JSONObjValue *gs = &s->values[i];
        if(gs->value->type == JSON_STRING) {
            cxMapPut(uwp_settings, cx_hash_key_str(gs->name), strdup(gs->value->value.string.string));
        }
    }
}

static char* get_which_output(FILE *f, CxBuffer *buf) {
    buf->pos = 0;
    buf->size = 0;
    cx_stream_copy(f, buf, (cx_read_func)fread, (cx_write_func)cxBufferWrite);
    if(!pclose(f)) {
        cxBufferPut(buf, 0);
        size_t i;
        for(i=0;i<buf->pos;i++) {
            if(buf->space[i] == '\n') {
                buf->space[i] = 0;
                break;
            }
        }
        return buf->space;
    }
    return NULL;
}

static Boolean finish_bin_search(XtPointer data) {
    PlayerInfo *playerInfo = data;
    cxMapPut(uwp_settings, cx_hash_key_str(UWP_PLAYER_BIN), playerInfo->bin);
    cxMapPut(uwp_settings, cx_hash_key_str(UWP_PLAYER_TYPE), playerInfo->type);
    free(playerInfo);
    return 0;
}

static void* player_bin_search_thread(void *data) {
    CxBuffer buf;
    cxBufferInit(&buf, NULL, 256, cxDefaultAllocator, CX_BUFFER_AUTO_EXTEND|CX_BUFFER_FREE_CONTENTS);
    
    FILE *f = popen("which mpv", "r");
    if(f) {
        char *bin = get_which_output(f, &buf);
        if(bin) {
            PlayerInfo *playerInfo = malloc(sizeof(PlayerInfo));
            playerInfo->bin = strdup(bin);
            playerInfo->type = strdup("mpv");
            AppExecProc(finish_bin_search, playerInfo);
            
            cxBufferDestroy(&buf);
            return NULL;
        }
    }
    
    f = popen("which mplayer", "r");
    if(f) {
        char *bin = get_which_output(f, &buf);
        if(bin) {
            PlayerInfo *playerInfo = malloc(sizeof(PlayerInfo));
            playerInfo->bin = strdup(bin);
            playerInfo->type = strdup("mplayer");
            AppExecProc(finish_bin_search, playerInfo);
        }
    }
    
    cxBufferDestroy(&buf);
    return NULL;
}

char* SettingsGetPlayerBin(void) {
    return cxMapGet(uwp_settings, cx_hash_key_str(UWP_PLAYER_BIN));
}


char *InstanceFilePath(Display *dp) {
    cxmutstr instance_file = cx_asprintf("instance%s", DisplayString(dp));
    char *path = util_concat_path(uwp_config_dir, instance_file.ptr);
    free(instance_file.ptr);
    return path;
}

int ConnectToInstance(const char *path) {
    int fd = socket(AF_UNIX, SOCK_STREAM, 0);
    if(!fd) {
        return -1;
    }
    
    size_t path_len = strlen(path);
    
    struct sockaddr_un addr;
    if(path_len > sizeof(addr.sun_path)-1) {
        return -1;
    }
    
    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
    memcpy(addr.sun_path, path, strlen(path) + 1);
    
    if(connect(fd, (struct sockaddr*)&addr, sizeof(addr))) {
        close(fd);
        return -1;
    }
    
    return fd;
}

int CreateSingleInstanceSocket(Display *dp, Bool *already_running) {
    char *instance_path = InstanceFilePath(dp);
    size_t instance_path_len = strlen(instance_path);
    *already_running = 0;
    
    // check path
    struct sockaddr_un addr;
    if(instance_path_len > sizeof(addr.sun_path)-1) {
        fprintf(stderr, "instance path '%s' too long for unix domain socket", instance_path);
        free(instance_path);
        return 1;
    }
    
    // check if the socket already exists and is open
    struct stat s;
    if(!stat(instance_path, &s)) {
        int fd = ConnectToInstance(instance_path);
        close(fd);
        if(fd >= 0) {
            *already_running = 1;
            return 0; // instance already running
        }
        
        // instance not running but socket file exists
        // remove socket before creating a new socket
        unlink(instance_path);
    }
    
    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
    memcpy(addr.sun_path, instance_path, instance_path_len+1);
    
    free(instance_path);
    instance_socket = socket(AF_UNIX, SOCK_STREAM, 0);
    if(instance_socket < 0) {
        fprintf(stderr, "cannot create instance socket: %s", strerror(errno));
        return 1;
    }
    
    if(bind(instance_socket, (struct sockaddr*)&addr, sizeof(addr))) {
        fprintf(stderr, "cannot bind instance socket: %s", strerror(errno));
        return 1;
    }
    
    pthread_t tid;
    if(pthread_create(&tid, NULL, instance_socket_thread, NULL)) {
        close(instance_socket);
        instance_socket = -1;
        return -1;
    }
    pthread_detach(tid);
    
    return 0;
}

static Boolean cmd_open(XtPointer data) {
    MainWindow *win = GetMainWindow();
    char *file = data;
    printf("open %s\n", file);
    
    PlayListClear(win);
    PlayListAddFile(win, file);
    PlayListPlayTrack(win, win->playlist.tracks->size-1);
    
    free(data);
    return 0;
}

static void process_msg(CxBuffer *msgbuf, size_t *rpos) {
    cxstring msg = cx_strn(NULL, 0);
    for(size_t i=*rpos;i<msgbuf->size;i++) {
        if(msgbuf->space[i] == '\n') {
            msg.ptr = msgbuf->space + *rpos;
            msg.length = i - *rpos;
            *rpos = i+1;
            break;
        }
    }
    
    if(msg.length > 0) {
        if(cx_strprefix(msg, CX_STR("open "))) {
            cxstring file = cx_strsubs(msg, 5);
            cxmutstr mfile = cx_strdup(file);
            AppExecProc(cmd_open, mfile.ptr);
        } else {
            fprintf(stderr, "unknown instance command: {%.*s}\n", (int)msg.length, msg.ptr);
        }
        
        if(*rpos < msgbuf->size) {
            process_msg(msgbuf, rpos);
        }
    }
}

void* instance_socket_thread(void *data) {
    listen(instance_socket, 8);
    
    CxBuffer msgbuf;
    cxBufferInit(&msgbuf, NULL, 1024, cxDefaultAllocator, CX_BUFFER_AUTO_EXTEND|CX_BUFFER_FREE_CONTENTS);
    
    char buf[1024];
    
    while(TRUE) {
        printf("accept instance socket\n");
        int fd = accept(instance_socket, NULL, 0);
        if(fd < 0) {
            break;
        }
        printf("accept instance connection\n");
        
        msgbuf.pos = 0;
        msgbuf.size = 0;
        size_t rpos = 0;
        
        ssize_t r;
        while((r = read(fd, buf, 1024)) > 0) {
            cxBufferWrite(buf, 1, r, &msgbuf);
            process_msg(&msgbuf, &rpos);
        }
        
        printf("close instance connection\n");
        close(fd);
    }
    
    cxBufferDestroy(&msgbuf);
    
    printf("instance socket shutdown\n");
    
    return NULL;
}

void ShutdownInstanceSocket(Display *dp) {
    if(instance_socket < 0) {
        return;
    }
    
    shutdown(instance_socket, SHUT_RDWR);
    close(instance_socket);
    instance_socket = -1;
    
    char *instance_path = InstanceFilePath(dp);
    unlink(instance_path);
    free(instance_path);
}