make: rules: added pagination_tags

needs tests, but is supposed to work

6 files changed, 260 insertions, 45 deletions

diff --git a/Makefile.am b/Makefile.am
index 12f9036..040f291 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -256,7 +256,6 @@ libblogc_make_la_CFLAGS = \
 	$(NULL)
 
 libblogc_make_la_LIBADD = \
-	$(LIBM) \
 	$(PTHREAD_LIBS) \
 	libblogc_common.la \
 	$(NULL)
diff --git a/man/blogc-make.1.ronn b/man/blogc-make.1.ronn
index 76f2f37..d44b685 100644
--- a/man/blogc-make.1.ronn
+++ b/man/blogc-make.1.ronn
@@ -114,6 +114,18 @@ The rule passes the following helper variables to blogc(1):
   * `MAKE_TYPE`:
     `post`
 
+### pagination_tags
+
+Build pagination pages for each tag from posts. This rule is disabled if
+`posts_per_page` value in blogcfile(5) is negative or `0`.
+
+The rule passes the following helper variables to blogc(1):
+
+  * `MAKE_RULE`:
+    `pagination_tags`
+  * `MAKE_TYPE`:
+    `post`
+
 ### posts
 
 Build individual pages for each post.
diff --git a/src/blogc-make/exec.c b/src/blogc-make/exec.c
index c36dc2d..c282a91 100644
--- a/src/blogc-make/exec.c
+++ b/src/blogc-make/exec.c
@@ -289,9 +289,8 @@ bm_exec_build_blogc_cmd(const char *blogc_bin, bm_settings_t *settings,
 
 int
 bm_exec_blogc(bm_ctx_t *ctx, bc_trie_t *global_variables, bc_trie_t *local_variables,
-    const char *print, bool listing, bm_filectx_t *listing_entry,
-    bm_filectx_t *template, bm_filectx_t *output, bc_slist_t *sources,
-    bool only_first_source)
+    bool listing, bm_filectx_t *listing_entry, bm_filectx_t *template,
+    bm_filectx_t *output, bc_slist_t *sources, bool only_first_source)
 {
     if (ctx == NULL)
         return 1;
@@ -304,7 +303,7 @@ bm_exec_blogc(bm_ctx_t *ctx, bc_trie_t *global_variables, bc_trie_t *local_varia
     }
 
     char *cmd = bm_exec_build_blogc_cmd(ctx->blogc, ctx->settings, global_variables,
-        local_variables, print, listing, listing_entry == NULL ? NULL : listing_entry->path,
+        local_variables, NULL, listing, listing_entry == NULL ? NULL : listing_entry->path,
         template->path, output->path, ctx->dev, input->len > 0);
 
     if (ctx->verbose)
@@ -370,6 +369,64 @@ bm_exec_blogc(bm_ctx_t *ctx, bc_trie_t *global_variables, bc_trie_t *local_varia
 }
 
 
+char*
+bm_exec_blogc_get_variable(bm_ctx_t *ctx, bc_trie_t *global_variables,
+    bc_trie_t *local_variables, const char *variable, bool listing,
+    bc_slist_t *sources, bool only_first_source)
+{
+    if (ctx == NULL)
+        return NULL;
+
+    bc_string_t *input = bc_string_new();
+    for (bc_slist_t *l = sources; l != NULL; l = l->next) {
+        bc_string_append_printf(input, "%s\n", ((bm_filectx_t*) l->data)->path);
+        if (only_first_source)
+            break;
+    }
+
+    char *cmd = bm_exec_build_blogc_cmd(ctx->blogc, ctx->settings, global_variables,
+        local_variables, variable, listing, NULL, NULL, NULL, ctx->dev, input->len > 0);
+
+    if (ctx->verbose)
+        printf("%s\n", cmd);
+    fflush(stdout);
+
+    char *out = NULL;
+    char *err = NULL;
+    bc_error_t *error = NULL;
+
+    int rv = bm_exec_command(cmd, input->str, &out, &err, &error);
+
+    if (error != NULL) {
+        bc_error_print(error, "blogc-make");
+        bc_error_free(error);
+        bc_string_free(input, true);
+        free(cmd);
+        free(out);
+        free(err);
+        return NULL;
+    }
+
+    if (rv != 0) {
+        fprintf(stderr, "blogc-make: error: %s\n", bc_str_strip(err));
+        bc_string_free(input, true);
+        free(cmd);
+        free(out);
+        free(err);
+        return NULL;
+    }
+
+    char *val = bc_strndup(out, strlen(out) - 1);
+
+    bc_string_free(input, true);
+    free(cmd);
+    free(out);
+    free(err);
+
+    return val;
+}
+
+
 int
 bm_exec_blogc_runserver(bm_ctx_t *ctx, const char *host, const char *port,
     const char *threads)
diff --git a/src/blogc-make/exec.h b/src/blogc-make/exec.h
index 140ef62..6bc206f 100644
--- a/src/blogc-make/exec.h
+++ b/src/blogc-make/exec.h
@@ -22,10 +22,13 @@ char* bm_exec_build_blogc_cmd(const char *blogc_bin, bm_settings_t *settings,
     bc_trie_t *global_variables, bc_trie_t *local_variables, const char *print,
     bool listing, const char *listing_entry, const char *template,
     const char *output, bool dev, bool sources_stdin);
-int bm_exec_blogc(bm_ctx_t *ctx, bc_trie_t *global_variables, bc_trie_t *local_variables,
-    const char *print, bool listing, bm_filectx_t *listing_entry,
+int bm_exec_blogc(bm_ctx_t *ctx, bc_trie_t *global_variables,
+    bc_trie_t *local_variables, bool listing, bm_filectx_t *listing_entry,
     bm_filectx_t *template, bm_filectx_t *output, bc_slist_t *sources,
     bool only_first_source);
+char* bm_exec_blogc_get_variable(bm_ctx_t *ctx, bc_trie_t *global_variables,
+    bc_trie_t *local_variables, const char *variable, bool listing,
+    bc_slist_t *sources, bool only_first_source);
 int bm_exec_blogc_runserver(bm_ctx_t *ctx, const char *host, const char *port,
     const char *threads);
 
diff --git a/src/blogc-make/main.c b/src/blogc-make/main.c
index d9f60b9..5b4a030 100644
--- a/src/blogc-make/main.c
+++ b/src/blogc-make/main.c
@@ -29,16 +29,16 @@ print_help(void)
         "               - A simple build tool for blogc.\n"
         "\n"
         "positional arguments:\n"
-        "    RULE          build rule(s) to run. can include comma-separated\n"
-        "                  key-value pairs of rule arguments in the format\n"
-        "                  RULE:arg1=value1,arg2=value2,... (default: all)\n"
+        "    RULE             build rule(s) to run. can include comma-separated\n"
+        "                     key-value pairs of rule arguments in the format\n"
+        "                     RULE:arg1=value1,arg2=value2,... (default: all)\n"
         "\n"
         "optional arguments:\n"
-        "    -h            show this help message and exit\n"
-        "    -v            show version and exit\n"
-        "    -D            build for development environment\n"
-        "    -V            be verbose when executing commands\n"
-        "    -f FILE       read FILE as blogcfile\n");
+        "    -h               show this help message and exit\n"
+        "    -v               show version and exit\n"
+        "    -D               build for development environment\n"
+        "    -V               be verbose when executing commands\n"
+        "    -f FILE          read FILE as blogcfile\n");
     bm_rule_print_help();
 }
 
diff --git a/src/blogc-make/rules.c b/src/blogc-make/rules.c
index 422f3a4..4d7a43e 100644
--- a/src/blogc-make/rules.c
+++ b/src/blogc-make/rules.c
@@ -11,7 +11,6 @@
 #include <string.h>
 #include <stdlib.h>
 #include <time.h>
-#include <math.h>
 #include "../common/utils.h"
 #include "atom.h"
 #include "ctx.h"
@@ -117,9 +116,8 @@ index_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx,
                 ctx->listing_entry_fctx, ctx->main_template_fctx, fctx, false))
         {
-            rv = bm_exec_blogc(ctx, variables, NULL, NULL, true,
-                ctx->listing_entry_fctx, ctx->main_template_fctx, fctx,
-                ctx->posts_fctx, false);
+            rv = bm_exec_blogc(ctx, variables, NULL, true, ctx->listing_entry_fctx,
+                ctx->main_template_fctx, fctx, ctx->posts_fctx, false);
             if (rv != 0)
                 break;
         }
@@ -177,8 +175,8 @@ atom_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx, NULL, NULL,
                 fctx, false))
         {
-            rv = bm_exec_blogc(ctx, variables, NULL, NULL, true, NULL,
-                ctx->atom_template_fctx, fctx, ctx->posts_fctx, false);
+            rv = bm_exec_blogc(ctx, variables, NULL, true, NULL, ctx->atom_template_fctx,
+                fctx, ctx->posts_fctx, false);
             if (rv != 0)
                 break;
         }
@@ -243,8 +241,8 @@ atom_tags_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx, NULL, NULL,
                 fctx, false))
         {
-            rv = bm_exec_blogc(ctx, variables, NULL, NULL, true, NULL,
-                ctx->atom_template_fctx, fctx, ctx->posts_fctx, false);
+            rv = bm_exec_blogc(ctx, variables, NULL, true, NULL, ctx->atom_template_fctx,
+                fctx, ctx->posts_fctx, false);
             if (rv != 0)
                 break;
         }
@@ -264,17 +262,24 @@ pagination_outputlist(bm_ctx_t *ctx)
     if (ctx == NULL || ctx->settings->posts == NULL)
         return NULL;
 
-    // not using posts_pagination_enabled() here because we need to calculate
-    // posts per page here anyway, and the condition is different.
-    long posts_per_page = strtol(bm_ctx_settings_lookup_str(ctx, "posts_per_page"),
-        NULL, 10);
-    if (posts_per_page <= 0)
+    if (!posts_pagination_enabled(ctx, "posts_per_page"))
         return NULL;
 
-    bc_slist_t *rv = NULL;
+    bc_trie_t *variables = bc_trie_new(free);
+    posts_pagination(ctx, variables, "posts_per_page");
+
+    char *last_page = bm_exec_blogc_get_variable(ctx, variables, NULL, "LAST_PAGE",
+        true, ctx->posts_fctx, false);
+
+    bc_trie_free(variables);
+
+    if (last_page == NULL)
+        return NULL;
 
-    long num_posts = bc_slist_length(ctx->posts_fctx);
-    size_t pages = ceilf(((float) num_posts) / posts_per_page);
+    long pages = strtol(last_page, NULL, 10);
+    free(last_page);
+
+    bc_slist_t *rv = NULL;
 
     const char *pagination_prefix = bm_ctx_settings_lookup(ctx, "pagination_prefix");
     const char *html_ext = bm_ctx_settings_lookup(ctx, "html_ext");
@@ -319,9 +324,142 @@ pagination_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx,
                 ctx->listing_entry_fctx, ctx->main_template_fctx, fctx, false))
         {
-            rv = bm_exec_blogc(ctx, variables, NULL, NULL, true,
-                ctx->listing_entry_fctx, ctx->main_template_fctx, fctx,
-                ctx->posts_fctx, false);
+            rv = bm_exec_blogc(ctx, variables, NULL, true, ctx->listing_entry_fctx,
+                ctx->main_template_fctx, fctx, ctx->posts_fctx, false);
+            if (rv != 0)
+                break;
+        }
+    }
+
+    bc_trie_free(variables);
+
+    return rv;
+}
+
+
+// PAGINATION TAGS RULE
+
+static bc_slist_t*
+pagination_tags_outputlist(bm_ctx_t *ctx)
+{
+    if (ctx == NULL || ctx->settings->posts == NULL || ctx->settings->tags == NULL)
+        return NULL;
+
+    if (!posts_pagination_enabled(ctx, "posts_per_page"))
+        return NULL;
+
+    bc_trie_t *variables = bc_trie_new(free);
+    posts_pagination(ctx, variables, "posts_per_page");
+
+    const char *tag_prefix = bm_ctx_settings_lookup(ctx, "tag_prefix");
+    const char *pagination_prefix = bm_ctx_settings_lookup(ctx, "pagination_prefix");
+    const char *html_ext = bm_ctx_settings_lookup(ctx, "html_ext");
+
+    bc_slist_t *rv = NULL;
+
+    for (size_t k = 0; ctx->settings->tags[k] != NULL; k++) {
+        bc_trie_t *local = bc_trie_new(free);
+        bc_trie_insert(local, "FILTER_TAG", bc_strdup(ctx->settings->tags[k]));
+
+        char *last_page = bm_exec_blogc_get_variable(ctx, variables, local,
+            "LAST_PAGE", true, ctx->posts_fctx, false);
+
+        bc_trie_free(local);
+
+        if (last_page == NULL)
+            break;
+
+        long pages = strtol(last_page, NULL, 10);
+        free(last_page);
+
+        char *prefix = bc_strdup_printf("%s/%s/%s", tag_prefix,
+            ctx->settings->tags[k], pagination_prefix);
+
+        for (size_t i = 0; i < pages; i++) {
+            char *j = bc_strdup_printf("%d", i + 1);
+            char *f = bm_generate_filename(ctx->short_output_dir, prefix,
+                j, html_ext);
+            rv = bc_slist_append(rv, bm_filectx_new(ctx, f, NULL, NULL));
+            free(j);
+            free(f);
+        }
+
+        free(prefix);
+    }
+
+    bc_trie_free(variables);
+
+    return rv;
+}
+
+static int
+pagination_tags_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
+{
+    if (ctx == NULL || ctx->settings->posts == NULL || ctx->settings->tags == NULL)
+        return 0;
+
+    int rv = 0;
+    size_t page = 1;
+
+    bc_trie_t *variables = bc_trie_new(free);
+    // not using posts_pagination because we set FILTER_PAGE anyway, and the
+    // first value inserted in that function would be useless
+    bc_trie_insert(variables, "FILTER_PER_PAGE",
+        bc_strdup(bm_ctx_settings_lookup_str(ctx, "posts_per_page")));
+    posts_ordering(ctx, variables, "html_order");
+    bc_trie_insert(variables, "DATE_FORMAT",
+        bc_strdup(bm_ctx_settings_lookup_str(ctx, "date_format")));
+    bc_trie_insert(variables, "MAKE_RULE", bc_strdup("pagination_tags"));
+    bc_trie_insert(variables, "MAKE_TYPE", bc_strdup("post"));
+
+    const char *tag_prefix = bm_ctx_settings_lookup(ctx, "tag_prefix");
+    const char *pagination_prefix = bm_ctx_settings_lookup(ctx, "pagination_prefix");
+    const char *html_ext = bm_ctx_settings_lookup(ctx, "html_ext");
+
+    for (bc_slist_t *l = outputs; l != NULL; l = l->next, page++) {
+        bm_filectx_t *fctx = l->data;
+        if (fctx == NULL)
+            continue;
+
+        // this is very expensive, but we don't have another way to detect the
+        // tag and page from the file path right now :/
+        char *tag = NULL;
+        for (size_t i = 0; ctx->settings->tags[i] != NULL; i++) {
+            char *prefix = bc_strdup_printf("%s/%s/%s", tag_prefix,
+                ctx->settings->tags[i], pagination_prefix);
+            bool b = false;
+
+            // it is impossible to have more output files per tag than the whole
+            // amount of output pages
+            for (size_t k = 0; k < bc_slist_length(outputs); k++) {
+                char *j = bc_strdup_printf("%d", k + 1);
+                char *f = bm_generate_filename(ctx->short_output_dir, prefix,
+                    j, html_ext);
+                free(j);
+                if (0 == strcmp(fctx->short_path, f)) {
+                    tag = ctx->settings->tags[i];
+                    page = k + 1;
+                    b = true;
+                    free(f);
+                    break;
+                }
+                free(f);
+            }
+            free(prefix);
+            if (b)
+                break;
+        }
+        if (tag == NULL)
+            continue;
+
+        bc_trie_insert(variables, "FILTER_TAG", bc_strdup(tag));
+        bc_trie_insert(variables, "FILTER_PAGE", bc_strdup_printf("%zu", page));
+
+        if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx,
+                ctx->listing_entry_fctx, ctx->main_template_fctx, fctx, false))
+        {
+            rv = bm_exec_blogc(ctx, variables, NULL, true, ctx->listing_entry_fctx,
+                ctx->main_template_fctx, fctx, ctx->posts_fctx, false);
             if (rv != 0)
                 break;
         }
@@ -386,8 +524,8 @@ posts_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         {
             bc_trie_t *local = bc_trie_new(NULL);
             bc_trie_insert(local, "MAKE_SLUG", s_fctx->slug);  // no need to copy
-            rv = bm_exec_blogc(ctx, variables, local, NULL, false, NULL,
-                ctx->main_template_fctx, o_fctx, s, true);
+            rv = bm_exec_blogc(ctx, variables, local, false, NULL, ctx->main_template_fctx,
+                o_fctx, s, true);
             bc_trie_free(local);
             if (rv != 0)
                 break;
@@ -454,9 +592,8 @@ tags_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         if (bm_rule_need_rebuild(ctx->posts_fctx, ctx->settings_fctx,
                 ctx->listing_entry_fctx, ctx->main_template_fctx, fctx, false))
         {
-            rv = bm_exec_blogc(ctx, variables, NULL, NULL, true,
-                ctx->listing_entry_fctx, ctx->main_template_fctx, fctx,
-                ctx->posts_fctx, false);
+            rv = bm_exec_blogc(ctx, variables, NULL, true, ctx->listing_entry_fctx,
+                ctx->main_template_fctx, fctx, ctx->posts_fctx, false);
             if (rv != 0)
                 break;
         }
@@ -518,8 +655,8 @@ pages_exec(bm_ctx_t *ctx, bc_slist_t *outputs, bc_trie_t *args)
         {
             bc_trie_t *local = bc_trie_new(NULL);
             bc_trie_insert(local, "MAKE_SLUG", s_fctx->slug); // no need to copy
-            rv = bm_exec_blogc(ctx, variables, local, NULL, false, NULL,
-                ctx->main_template_fctx, o_fctx, s, true);
+            rv = bm_exec_blogc(ctx, variables, local, false, NULL, ctx->main_template_fctx,
+                o_fctx, s, true);
             bc_trie_free(local);
             if (rv != 0)
                 break;
@@ -687,6 +824,13 @@ const bm_rule_t rules[] = {
         .generate_files = true,
     },
     {
+        .name = "pagination_tags",
+        .help = "build pagination pages for each tag from posts",
+        .outputlist_func = pagination_tags_outputlist,
+        .exec_func = pagination_tags_exec,
+        .generate_files = true,
+    },
+    {
         .name = "posts",
         .help = "build individual pages for each post",
         .outputlist_func = posts_outputlist,
@@ -724,8 +868,8 @@ const bm_rule_t rules[] = {
     {
         .name = "runserver",
         .help = "run blogc-runserver pointing to output directory, if available,\n"
-            "                  rebuilding as needed\n"
-            "                  arguments: host (127.0.0.1), port (8080) and threads (20)",
+            "                     rebuilding as needed\n"
+            "                     arguments: host (127.0.0.1), port (8080) and threads (20)",
         .outputlist_func = NULL,
         .exec_func = runserver_exec,
         .generate_files = false,
@@ -946,13 +1090,13 @@ bm_rule_print_help(void)
     printf("\nhelper rules:\n");
     for (size_t i = 0; rules[i].name != NULL; i++) {
         if (!rules[i].generate_files) {
-            printf("    %-12s  %s\n", rules[i].name, rules[i].help);
+            printf("    %-15s  %s\n", rules[i].name, rules[i].help);
         }
     }
     printf("\nbuild rules:\n");
     for (size_t i = 0; rules[i].name != NULL; i++) {
         if (rules[i].generate_files) {
-            printf("    %-12s  %s\n", rules[i].name, rules[i].help);
+            printf("    %-15s  %s\n", rules[i].name, rules[i].help);
         }
     }
 }