/**

 * @file yangdata.c

 * @author Radek Krejci <rkrejci@cesnet.cz>

 * @author Michal Vasko <mvasko@cesnet.cz>

 * @brief libyang extension plugin - yang-data (RFC 8040)

 *

 * Copyright (c) 2021 - 2026 CESNET, z.s.p.o.

 *

 * This source code is licensed under BSD 3-Clause License (the "License").

 * You may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     https://opensource.org/licenses/BSD-3-Clause

 */

#include <assert.h>

#include <stdint.h>

#include <stdlib.h>

#include <string.h>

#include "compat.h"

#include "libyang.h"

#include "ly_common.h"

#include "plugins_exts.h"

#include "plugins_types.h"

static LY_ERR yangdata_snode(struct lysc_ext_instance *ext, const struct lyd_node *parent, const struct lysc_node *sparent,

        const char *prefix, uint32_t prefix_len, LY_VALUE_FORMAT format, void *prefix_data, const char *name,

        uint32_t name_len, const struct lysc_node **snode);

static void yangdata_cfree(const struct ly_ctx *ctx, struct lysc_ext_instance *ext);

/**

 * @brief Parse yang-data extension instances.

 *

 * Implementation of ::lyplg_ext_parse_clb callback set as lyext_plugin::parse.

 */

static LY_ERR

yangdata_parse(struct lysp_ctx *pctx, struct lysp_ext_instance *ext)

{

    LY_ERR ret;

    LY_ARRAY_COUNT_TYPE u;

    struct lysp_module *pmod;

    /* yang-data can appear only at the top level of a YANG module or submodule */

    if ((ext->parent_stmt != LY_STMT_MODULE) && (ext->parent_stmt != LY_STMT_SUBMODULE)) {

        lyplg_ext_parse_log(pctx, ext, LY_LLWRN, 0, "Extension %s is ignored since it appears as a non top-level statement "

                "in \"%s\" statement.", ext->name, lyplg_ext_stmt2str(ext->parent_stmt));

        return LY_ENOT;

    }

    pmod = ext->parent;

    /* check for duplication */

    LY_ARRAY_FOR(pmod->exts, u) {

        if ((&pmod->exts[u] != ext) && (pmod->exts[u].name == ext->name) && !strcmp(pmod->exts[u].argument, ext->argument)) {

            /* duplication of the same yang-data extension in a single module */

            lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EVALID, "Extension %s is instantiated multiple times.", ext->name);

            return LY_EVALID;

        }

    }

    /* parse yang-data substatements */

    LY_ARRAY_CREATE_GOTO(lyplg_ext_parse_get_cur_pmod(pctx)->mod->ctx, ext->substmts, 3, ret, emem);

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[0].stmt = LY_STMT_CONTAINER;

    ext->substmts[0].storage_p = (void **)&ext->parsed;

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[1].stmt = LY_STMT_CHOICE;

    ext->substmts[1].storage_p = (void **)&ext->parsed;

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[2].stmt = LY_STMT_USES;

    ext->substmts[2].storage_p = (void **)&ext->parsed;

    if ((ret = lyplg_ext_parse_extension_instance(pctx, ext))) {

        return ret;

    }

    return LY_SUCCESS;

emem:

    lyplg_ext_parse_log(pctx, ext, LY_LLERR, LY_EMEM, "Memory allocation failed (%s()).", __func__);

    return LY_EMEM;

}

/**

 * @brief Compile yang-data extension instances.

 *

 * Implementation of ::lyplg_ext_compile_clb callback set as lyext_plugin::compile.

 */

static LY_ERR

yangdata_compile(struct lysc_ctx *cctx, const struct lysp_ext_instance *extp, struct lysc_ext_instance *ext)

{

    LY_ERR ret;

    const struct lysc_node *child;

    ly_bool valid = 1;

    uint32_t prev_options = *lyplg_ext_compile_get_options(cctx);

    /* compile yangg-data substatements */

    LY_ARRAY_CREATE_GOTO(cctx->ctx, ext->substmts, 3, ret, emem);

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[0].stmt = LY_STMT_CONTAINER;

    ext->substmts[0].storage_p = (void **)&ext->compiled;

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[1].stmt = LY_STMT_CHOICE;

    ext->substmts[1].storage_p = (void **)&ext->compiled;

    LY_ARRAY_INCREMENT(ext->substmts);

    ext->substmts[2].stmt = LY_STMT_USES;

    ext->substmts[2].storage_p = (void **)&ext->compiled;

    *lyplg_ext_compile_get_options(cctx) |= LYS_COMPILE_NO_CONFIG | LYS_COMPILE_NO_DISABLED;

    ret = lyplg_ext_compile_extension_instance(cctx, extp, ext, NULL);

    *lyplg_ext_compile_get_options(cctx) = prev_options;

    if (ret) {

        return ret;

    }

    /* check that we have really just a single container data definition in the top */

    child = ext->compiled;

    if (!child) {

        valid = 0;

        lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EVALID,

                "Extension %s is instantiated without any top level data node, but exactly one container data node is expected.",

                extp->name);

    } else if (child->next) {

        valid = 0;

        lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EVALID,

                "Extension %s is instantiated with multiple top level data nodes, but only a single container data node is allowed.",

                extp->name);

    } else if (child->nodetype == LYS_CHOICE) {

        /* all the choice's case are expected to result to a single container node */

        struct lysc_module *mod_c = ext->parent;

        const struct lysc_node *snode = NULL;

        while ((snode = lys_getnext(snode, child, mod_c, 0))) {

            if (snode->next) {

                valid = 0;

                lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EVALID,

                        "Extension %s is instantiated with multiple top level data nodes (inside a single choice's case), "

                        "but only a single container data node is allowed.", extp->name);

                break;

            } else if (snode->nodetype != LYS_CONTAINER) {

                valid = 0;

                lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EVALID,

                        "Extension %s is instantiated with %s top level data node (inside a choice), "

                        "but only a single container data node is allowed.", extp->name, lys_nodetype2str(snode->nodetype));

                break;

            }

        }

    } else if (child->nodetype != LYS_CONTAINER) {

        /* via uses */

        valid = 0;

        lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EVALID,

                "Extension %s is instantiated with %s top level data node, but only a single container data node is allowed.",

                extp->name, lys_nodetype2str(child->nodetype));

    }

    if (!valid) {

        yangdata_cfree(lyplg_ext_compile_get_ctx(cctx), ext);

        ext->compiled = ext->substmts = NULL;

        return LY_EVALID;

    }

    return LY_SUCCESS;

emem:

    lyplg_ext_compile_log(cctx, ext, LY_LLERR, LY_EMEM, "Memory allocation failed (%s()).", __func__);

    return LY_EMEM;

}

/**

 * @brief INFO printer

 *

 * Implementation of ::lyplg_ext_sprinter_info_clb set as ::lyext_plugin::printer_info

 */

static LY_ERR

yangdata_printer_info(struct lyspr_ctx *ctx, struct lysc_ext_instance *ext, ly_bool *flag)

{

    lyplg_ext_print_info_extension_instance(ctx, ext, flag);

    return LY_SUCCESS;

}

/**

 * @brief Snode xpath callback for yang-data.

 */

static LY_ERR

yangdata_snode_xpath(struct lysc_ext_instance *ext, const char *prefix, uint32_t prefix_len, LY_VALUE_FORMAT format,

        void *prefix_data, const char *name, uint32_t name_len, const struct lysc_node **snode)

{

    return yangdata_snode(ext, NULL, NULL, prefix, prefix_len, format, prefix_data, name, name_len, snode);

}

/**

 * @brief Snode callback for yang-data.

 */

static LY_ERR

yangdata_snode(struct lysc_ext_instance *ext, const struct lyd_node *parent, const struct lysc_node *sparent,

        const char *prefix, uint32_t prefix_len, LY_VALUE_FORMAT format, void *prefix_data, const char *name,

        uint32_t name_len, const struct lysc_node **snode)

{

    const struct lysc_node *schema = ext->compiled;

    const struct lys_module *mod;

    if (parent || sparent) {

        /* matches only top-level data */

        return LY_ENOT;

    }

    if (prefix && prefix_len) {

        /* check module */

        mod = lys_find_module(ext->module->ctx, NULL, prefix, prefix_len, format, prefix_data);

        if (!mod || (ext->module != mod)) {

            return LY_ENOT;

        }

    }

    /* check name */

    if (name && name_len) {

        LY_LIST_FOR(schema, schema) {

            if (!ly_strncmp(schema->name, name, name_len)) {

                break;

            }

        }

    }

    /* first top-level node or the found one, if any */

    *snode = schema;

    return schema ? LY_SUCCESS : LY_ENOT;

}

/**

 * @brief Validate callback for yang-data.

 */

static LY_ERR

yangdata_validate(struct lysc_ext_instance *ext, struct lyd_node *node, const struct lyd_node *UNUSED(dep_tree),

        enum lyd_type data_type, uint32_t val_opts, struct lyd_node **diff)

{

    if (data_type != LYD_TYPE_DATA_YANG) {

        /* not supported */

        return LY_ENOT;

    }

    /* validate all the modules with data */

    return lyd_validate_ext(&node, ext, val_opts, diff);

}

/**

 * @brief Free parsed yang-data extension instance data.

 *

 * Implementation of ::lyplg_clb_parse_free_clb callback set as lyext_plugin::pfree.

 */

static void

yangdata_pfree(const struct ly_ctx *ctx, struct lysp_ext_instance *ext)

{

    lyplg_ext_pfree_instance_substatements(ctx, ext->substmts);

}

/**

 * @brief Free compiled yang-data extension instance data.

 *

 * Implementation of ::lyplg_clb_compile_free_clb callback set as lyext_plugin::cfree.

 */

static void

yangdata_cfree(const struct ly_ctx *ctx, struct lysc_ext_instance *ext)

{

    lyplg_ext_cfree_instance_substatements(ctx, ext->substmts);

}

static int

yandgata_compiled_size(const struct lysc_ext_instance *ext, struct ly_ht *addr_ht)

{

    return lyplg_ext_compiled_stmts_storage_size(ext->substmts, addr_ht);

}

static LY_ERR

yangdata_compiled_print(const struct lysc_ext_instance *orig_ext, struct lysc_ext_instance *ext, struct ly_ht *addr_ht,

        struct ly_set *ptr_set, void **mem)

{

    ext->compiled = NULL;

    ext->substmts[0].storage_p = (void **)&ext->compiled;

    ext->substmts[1].storage_p = (void **)&ext->compiled;

    ext->substmts[2].storage_p = (void **)&ext->compiled;

    return lyplg_ext_compiled_stmts_storage_print(orig_ext->substmts, ext->substmts, addr_ht, ptr_set, mem);

}

/**

 * @brief Plugin descriptions for the yang-data extension

 *

 * Note that external plugins are supposed to use:

 *

 *   LYPLG_EXTENSIONS = {

 */

const struct lyplg_ext_record plugins_yangdata[] = {

    {

        .module = "ietf-restconf",

        .revision = "2017-01-26",

        .name = "yang-data",

        .plugin.id = "ly2 yang-data",

        .plugin.parse = yangdata_parse,

        .plugin.compile = yangdata_compile,

        .plugin.printer_info = yangdata_printer_info,

        .plugin.node_xpath = NULL,

        .plugin.snode_xpath = yangdata_snode_xpath,

        .plugin.snode = yangdata_snode,

        .plugin.validate = yangdata_validate,

        .plugin.pfree = yangdata_pfree,

        .plugin.cfree = yangdata_cfree,

        .plugin.compiled_size = yandgata_compiled_size,

        .plugin.compiled_print = yangdata_compiled_print

    },

    {0}     /* terminating zeroed record */

};