Add the ability to add rss from episode name

6 files changed, 322 insertions, 5 deletions

diff --git a/build.sh b/build.sh
index 9ecbe97..3acb657 100755
--- a/build.sh
+++ b/build.sh
@@ -2,4 +2,4 @@
 
 CFLAGS="-O3 -s -flto"
 [ -z "$RELEASE" ] && CFLAGS="-O0 -g3 -Wall -Wextra -Werror";
-musl-gcc -static src/main.c src/program.c src/alloc.c src/buffer.c src/fileutils.c src/transmission.c src/rss.c src/html.c src/rss_html_common.c src/download.c src/stringutils.c -o automedia $CFLAGS
+musl-gcc -static src/main.c src/program.c src/alloc.c src/buffer.c src/fileutils.c src/transmission.c src/rss.c src/html.c src/rss_html_common.c src/download.c src/stringutils.c src/episode.c -o automedia $CFLAGS
diff --git a/src/download.c b/src/download.c
index 74348e5..4154dcb 100644
--- a/src/download.c
+++ b/src/download.c
@@ -18,3 +18,15 @@ int download_to_buffer(const char *url, Buffer *buffer) {
     buffer_append(buffer, "\0", 1);
     return result;
 }
+
+int is_header_response_ok(const char *url) {
+    const char *args[] = {
+        "curl", "-s", "-L", "-f", "-I",
+        "-H", "user-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36",
+        "-H", "Accept-Language: en-US,en;q=0.5",
+        "--",
+        url,
+        NULL
+    };
+    return program_exec(args, NULL, NULL);
+}
diff --git a/src/download.h b/src/download.h
index 0682ba9..3c7f0aa 100644
--- a/src/download.h
+++ b/src/download.h
@@ -3,5 +3,6 @@
 
 struct Buffer;
 int download_to_buffer(const char *url, struct Buffer *buffer);
+int is_header_response_ok(const char *url);
 
 #endif
diff --git a/src/episode.c b/src/episode.c
new file mode 100644
index 0000000..e89195c
--- /dev/null
+++ b/src/episode.c
@@ -0,0 +1,133 @@
+#include "episode.h"
+#include "stringutils.h"
+#include <stdio.h>
+#include <string.h>
+
+static int string_find(const char *str, int len, int offset, char char_to_find) {
+    for(int i = offset; i < len; ++i) {
+        if(str[i] == char_to_find)
+            return i;
+    }
+    return -1;
+}
+
+static int string_rfind(const char *str, int len, int offset, char char_to_find) {
+    for(int i = offset - 1; i >= 0; --i) {
+        if(str[i] == char_to_find)
+            return i + (len - offset);
+    }
+    return -1;
+}
+
+int episode_info_create_from_episode_name(EpisodeInfo *self, const char *episode_name) {
+    self->episode_name[0] = '\0';
+    self->group_name = NULL;
+    self->anime_name = NULL;
+    self->episode = NULL;
+    self->resolution = NULL;
+    self->extension = NULL;
+
+    int episode_name_len = strlen(episode_name);
+    if(episode_name_len > 500) {
+        fprintf(stderr, "Episode name is too long! it can't be more than 500 characters\n");
+        return -1;
+    }
+
+    char episode_name_s[512];
+    strcpy(episode_name_s, episode_name);
+    char *episode_name_stripped = strip(episode_name_s);
+    int episode_name_stripped_len = strlen(episode_name_stripped);
+    int episode_name_offset = 0;
+
+    if(episode_name_stripped_len == 0)
+        return -1;
+
+    int extension_index = string_rfind(episode_name_stripped, episode_name_stripped_len, episode_name_stripped_len, '.');
+    if(extension_index != -1) {
+        int extension_len = episode_name_stripped_len - extension_index;
+        self->extension = self->episode_name + episode_name_offset;
+        memcpy(self->extension, episode_name_stripped + extension_index, extension_len);
+        self->extension[extension_len] = '\0';
+        episode_name_offset += extension_len + 1;
+        episode_name_stripped_len = extension_index;
+    }
+
+    if(episode_name_stripped[0] != '[')
+        return -1;
+
+    int group_name_end = string_find(episode_name_stripped, episode_name_stripped_len, 0, ']');
+    if(group_name_end == -1)
+        return -1;
+
+    int group_name_len = group_name_end - 1;
+    self->group_name = self->episode_name + episode_name_offset;
+    memcpy(self->group_name, episode_name_stripped + 1, group_name_len);
+    self->group_name[group_name_len] = '\0';
+    self->group_name = strip(self->group_name);
+    episode_name_offset += group_name_len + 1;
+
+    int last_dash = string_rfind(episode_name_stripped, episode_name_stripped_len, episode_name_stripped_len, '-');
+    if(last_dash == -1)
+        return -1;
+
+    int anime_name_len = last_dash - 1 - group_name_end;
+    self->anime_name = self->episode_name + episode_name_offset;
+    memcpy(self->anime_name, episode_name_stripped + group_name_end + 1, anime_name_len);
+    self->anime_name[anime_name_len] = '\0';
+    self->anime_name = strip(self->anime_name);
+    episode_name_offset += anime_name_len + 1;
+
+    int resolution_index = string_find(episode_name_stripped, episode_name_stripped_len, last_dash + 1, '[');
+    if(resolution_index == -1) {
+        /* TODO: Test if this works */
+        int episode_len = episode_name_stripped_len - (last_dash + 1);
+        self->episode = self->episode_name + episode_name_offset;
+        memcpy(self->episode, episode_name_stripped + last_dash + 1, episode_len);
+        self->episode[episode_len] = '\0';
+        self->episode = strip(self->episode);
+        episode_name_offset += episode_len + 1;
+    } else {
+        int episode_len = resolution_index - (last_dash + 1);
+        self->episode = self->episode_name + episode_name_offset;
+        memcpy(self->episode, episode_name_stripped + last_dash + 1, episode_len);
+        self->episode[episode_len] = '\0';
+        self->episode = strip(self->episode);
+        episode_name_offset += episode_len + 1;
+
+        int resolution_end = string_find(episode_name_stripped, episode_name_stripped_len, resolution_index + 1, ']');
+        if(resolution_end != -1) {
+            int resolution_len = resolution_end - (resolution_index + 1);
+            self->resolution = self->episode_name + episode_name_offset;
+            memcpy(self->resolution, episode_name_stripped + resolution_index + 1, resolution_len);
+            self->resolution[resolution_len] = '\0';
+            self->resolution = strip(self->resolution);
+        }
+    }
+    
+    return 0;
+}
+
+int episode_info_get_generic_name(EpisodeInfo *self, char *output_buffer, int output_buffer_size) {
+    if(!self->group_name || !self->anime_name)
+        return -1;
+    
+    int bytes_written = 0;
+    if(self->resolution) {
+        if(self->extension)
+            bytes_written = snprintf(output_buffer, output_buffer_size, "[%s] %s [%s]%s", self->group_name, self->anime_name, self->resolution, self->extension);
+        else
+            bytes_written = snprintf(output_buffer, output_buffer_size, "[%s] %s [%s]", self->group_name, self->anime_name, self->resolution);
+    } else {
+        if(self->extension)
+            bytes_written = snprintf(output_buffer, output_buffer_size, "[%s] %s%s", self->group_name, self->anime_name, self->extension);
+        else
+            bytes_written = snprintf(output_buffer, output_buffer_size, "[%s] %s", self->group_name, self->anime_name);
+    }
+    
+    if(bytes_written >= output_buffer_size) {
+        fprintf(stderr, "Failed to write generic name to buffer\n");
+        return -1;
+    }
+
+    return 0;
+}
diff --git a/src/episode.h b/src/episode.h
new file mode 100644
index 0000000..66c4e8a
--- /dev/null
+++ b/src/episode.h
@@ -0,0 +1,19 @@
+#ifndef EPISODE_H
+#define EPISODE_H
+
+typedef struct {
+    char episode_name[512];
+
+    /* These are pointers inside @episode_name */
+    char *group_name;
+    char *anime_name;
+    char *episode;
+    char *resolution;
+    char *extension;
+} EpisodeInfo;
+
+/* Fails if @episode_name is more than 500 characters long or if group or anime name is missing/cant be parsed */
+int episode_info_create_from_episode_name(EpisodeInfo *self, const char *episode_name);
+int episode_info_get_generic_name(EpisodeInfo *self, char *output_buffer, int output_buffer_size);
+
+#endif
diff --git a/src/rss.c b/src/rss.c
index 442fb58..9486e6e 100644
--- a/src/rss.c
+++ b/src/rss.c
@@ -4,6 +4,7 @@
 #include "stringutils.h"
 #include "fileutils.h"
 #include "buffer.h"
+#include "episode.h"
 #include "rss_html_common.h"
 #include "json.h"
 #include "alloc.h"
@@ -165,6 +166,139 @@ static int rss_parse_add_callback(char *title, char *link, void *userdata) {
     return 0;
 }
 
+static const char hex_characters[] = "0123456789ABCDEF";
+/* TODO: Also support unicode escape characters */
+static void url_escape(const char *str, char *output) {
+    int index = 0;
+    for(;;) {
+        char c = *str;
+        if(c == '\0') {
+            output[index] = '\0';
+            break;
+        } else if(c < 32) {
+            output[index++] = '%';
+            output[index++] = hex_characters[(c>>4) & 0x0F];
+            output[index++] = hex_characters[c&0x0F];
+        } else {
+            switch(c) {
+                case '!':
+                case '#':
+                case '$':
+                case '%':
+                case '&':
+                case '\'':
+                case '(':
+                case ')':
+                case '*':
+                case '+':
+                case ',':
+                case '/':
+                case ':':
+                case ';':
+                case '=':
+                case '?':
+                case '@':
+                case '[':
+                case ']':
+                case '"':
+                case '-':
+                case '.':
+                case '<':
+                case '>':
+                case '\\':
+                case '^':
+                case '_':
+                case '`':
+                case '{':
+                case '|':
+                case '}':
+                case '~':
+                case ' ':
+                    output[index++] = '%';
+                    output[index++] = hex_characters[(c>>4) & 0x0F];
+                    output[index++] = hex_characters[c&0x0F];
+                    break;
+                default:
+                    output[index++] = c;
+                    break;
+            }
+        }
+        ++str;
+    }
+}
+
+static int get_rss_url_from_episode_info(const char *episode_name, EpisodeInfo *episode_info, char *rss_url) {
+    char *selected_submitter = NULL;
+    char response[512];
+    char group_name_escaped[1536];
+    
+    for(;;) {
+        printf("Enter the name of the submitter (leave empty to choose \"%s\" or type \"anon\" to choose all submitters: ", episode_info->group_name);
+        if(!fgets(response, sizeof(response), stdin)) {
+            fprintf(stderr, "Failed to read response from stdin\n");
+            return -1;
+        }
+        fprintf(stderr, "response: %s\n", response);
+        char *response_str = strip(response);
+
+        if(strcmp(response, "anon") == 0) {
+            break;
+        } else {
+            if(strlen(response_str) == 0)
+                response_str = episode_info->group_name;
+            
+            url_escape(response, group_name_escaped);
+            char url[4096];
+            if(snprintf(url, sizeof(url), "https://nyaa.si/user/%s", group_name_escaped) >= (int)sizeof(url)) {
+                fprintf(stderr, "Error: url is too long!\n");
+                return -1;
+            }
+
+            if(is_header_response_ok(url) == 0) {
+                selected_submitter = response_str;
+                break;
+            } else {
+                printf("The submitter \"%s\" doesn't exist on nyaa.si, please choose another submitter.\n", response_str);
+            }
+        }
+    }
+
+    char generic_name[2048];
+    if(episode_info_get_generic_name(episode_info, generic_name, sizeof(generic_name)) != 0) {
+        fprintf(stderr, "Failed to get name for episode!\n");
+        return -1;
+    }
+
+    for(;;) {
+        if(selected_submitter)
+            printf("Are you sure you want to track \"%s\" by %s after \"%s\" ? (Y)es/No: ", generic_name, selected_submitter, episode_name);
+        else
+            printf("Are you sure you want to track \"%s\" by all submitters after \"%s\" ? (Y)es/No: ", generic_name, episode_name);
+        
+        char sresp[128];
+        if(!fgets(sresp, sizeof(sresp), stdin)) {
+            fprintf(stderr, "Failed to read response from stdin\n");
+            return -1;
+        }
+        char *response_str = strip(response);
+        int response_len = strlen(response_str);
+
+        if(response_len > 0 && (response_str[0] == 'n' || response_str[0] == 'N')) {
+            rss_url[0] = '\0';
+            return 0;
+        } else if(response_len == 0 || response_str[0] == 'y' || response_str[0] == 'Y') {
+            break;
+        }
+    }
+
+    if(selected_submitter)
+        sprintf(rss_url, "https://nyaa.si/?page=rss&q=%s&c=0_0&f=0&u=%s", group_name_escaped, selected_submitter);
+    else
+        sprintf(rss_url, "https://nyaa.si/?page=rss&q=%s&c=0_0&f=0", group_name_escaped);
+
+    return 0;
+}
+
 int add_rss(const char *name, const char *url, char *rss_config_dir, const char *start_after) {
     int result = 0;
 
@@ -172,8 +306,28 @@ int add_rss(const char *name, const char *url, char *rss_config_dir, const char
     buffer_init(&buffer);
     result = download_to_buffer(url, &buffer);
     if(result != 0) {
-        fprintf(stderr, "Failed to download rss: %s\n", url);
-        goto cleanup;
+        EpisodeInfo episode_info;
+        if(episode_info_create_from_episode_name(&episode_info, url) != 0) {
+            fprintf(stderr, "Failed to download rss: %s\n", url);
+            goto cleanup;
+        }
+
+        char rss_url[4096];
+        if(get_rss_url_from_episode_info(url, &episode_info, rss_url) != 0)
+            goto cleanup;
+
+        /* User didn't want to track rss */
+        if(rss_url[0] == '\0') {
+            result = 0;
+            goto cleanup;
+        }
+
+        buffer_clear(&buffer);
+        result = download_to_buffer(url, &buffer);
+        if(result != 0) {
+            fprintf(stderr, "Failed to download rss: %s\n", url);
+            goto cleanup;
+        }
     }
 
     RssParseUserdata rss_parse_userdata;
@@ -194,8 +348,6 @@ int add_rss(const char *name, const char *url, char *rss_config_dir, const char
         goto cleanup;
     }
 
-    /* TODO: Add (add rss <episode name>) here */
-
     if(!name) {
         if(!rss_title) {
             fprintf(stderr, "Failed to find rss title and --name was not provided\n");