/**
 * @file common.c
 * @author Radek Krejci <rkrejci@cesnet.cz>
 * @brief libyang's yanglint tool - common functions for both interactive and non-interactive mode.
 *
 * Copyright (c) 2020 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
 */

#define _GNU_SOURCE
#define _POSIX_C_SOURCE 200809L /* strdup, strndup */

#include "common.h"

#include <assert.h>
#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#include "compat.h"
#include "libyang.h"

int
parse_schema_path(const char *path, char **dir, char **module)
{
    char *p;

    assert(dir);
    assert(module);

    /* split the path to dirname and basename for further work */
    *dir = strdup(path);
    *module = strrchr(*dir, '/');
    if (!(*module)) {
        *module = *dir;
        *dir = strdup("./");
    } else {
        *module[0] = '\0'; /* break the dir */
        *module = strdup((*module) + 1);
    }
    /* get the pure module name without suffix or revision part of the filename */
    if ((p = strchr(*module, '@'))) {
        /* revision */
        *p = '\0';
    } else if ((p = strrchr(*module, '.'))) {
        /* fileformat suffix */
        *p = '\0';
    }

    return 0;
}

int
get_input(const char *filepath, LYS_INFORMAT *format_schema, LYD_FORMAT *format_data, struct ly_in **in)
{
    struct stat st;

    /* check that the filepath exists and is a regular file */
    if (stat(filepath, &st) == -1) {
        YLMSG_E("Unable to use input filepath (%s) - %s.\n", filepath, strerror(errno));
        return -1;
    }
    if (!S_ISREG(st.st_mode)) {
        YLMSG_E("Provided input file (%s) is not a regular file.\n", filepath);
        return -1;
    }

    if ((format_schema && !*format_schema) || (format_data && !*format_data)) {
        /* get the file format */
        if (get_format(filepath, format_schema, format_data)) {
            return -1;
        }
    }

    if (ly_in_new_filepath(filepath, 0, in)) {
        YLMSG_E("Unable to process input file.\n");
        return -1;
    }

    return 0;
}

void
free_features(void *flist)
{
    struct schema_features *rec = (struct schema_features *)flist;

    if (rec) {
        free(rec->mod_name);
        if (rec->features) {
            for (uint32_t u = 0; rec->features[u]; ++u) {
                free(rec->features[u]);
            }
            free(rec->features);
        }
        free(rec);
    }
}

void
get_features(struct ly_set *fset, const char *module, const char ***features)
{
    /* get features list for this module */
    for (uint32_t u = 0; u < fset->count; ++u) {
        struct schema_features *sf = (struct schema_features *)fset->objs[u];
        if (!strcmp(module, sf->mod_name)) {
            /* matched module - explicitly set features */
            *features = (const char **)sf->features;
            sf->applied = 1;
            return;
        }
    }

    /* features not set so disable all */
    *features = NULL;
}

int
parse_features(const char *fstring, struct ly_set *fset)
{
    struct schema_features *rec;
    char *p;

    rec = calloc(1, sizeof *rec);
    if (!rec) {
        YLMSG_E("Unable to allocate features information record (%s).\n", strerror(errno));
        return -1;
    }
    if (ly_set_add(fset, rec, 1, NULL)) {
        YLMSG_E("Unable to store features information (%s).\n", strerror(errno));
        free(rec);
        return -1;
    }

    /* fill the record */
    p = strchr(fstring, ':');
    if (!p) {
        YLMSG_E("Invalid format of the features specification (%s).\n", fstring);
        return -1;
    }
    rec->mod_name = strndup(fstring, p - fstring);

    /* start count on 2 to include terminating NULL byte */
    for (int count = 2; p; ++count) {
        size_t len = 0;
        char *token = p + 1;
        p = strchr(token, ',');
        if (!p) {
            /* the last item, if any */
            len = strlen(token);
        } else {
            len = p - token;
        }
        if (len) {
            char **fp = realloc(rec->features, count * sizeof *rec->features);
            if (!fp) {
                YLMSG_E("Unable to store features list information (%s).\n", strerror(errno));
                return -1;
            }
            rec->features = fp;
            rec->features[count - 1] = NULL; /* terminating NULL-byte */
            fp = &rec->features[count - 2]; /* array item to set */
            (*fp) = strndup(token, len);
        }
    }

    return 0;
}

struct cmdline_file *
fill_cmdline_file(struct ly_set *set, struct ly_in *in, const char *path, LYD_FORMAT format)
{
    struct cmdline_file *rec;

    rec = malloc(sizeof *rec);
    if (!rec) {
        YLMSG_E("Allocating memory for data file information failed.\n");
        return NULL;
    }
    if (set && ly_set_add(set, rec, 1, NULL)) {
        free(rec);
        YLMSG_E("Storing data file information failed.\n");
        return NULL;
    }
    rec->in = in;
    rec->path = path;
    rec->format = format;

    return rec;
}

void
free_cmdline_file(void *cmdline_file)
{
    struct cmdline_file *rec = (struct cmdline_file *)cmdline_file;

    if (rec) {
        ly_in_free(rec->in, 1);
        free(rec);
    }
}

void
free_cmdline(char *argv[])
{
    if (argv) {
        free(argv[0]);
        free(argv);
    }
}

int
parse_cmdline(const char *cmdline, int *argc_p, char **argv_p[])
{
    int count;
    char **vector;
    char *ptr;
    char qmark = 0;

    assert(cmdline);
    assert(argc_p);
    assert(argv_p);

    /* init */
    optind = 0; /* reinitialize getopt() */
    count = 1;
    vector = malloc((count + 1) * sizeof *vector);
    vector[0] = strdup(cmdline);

    /* command name */
    strtok(vector[0], " ");

    /* arguments */
    while ((ptr = strtok(NULL, " "))) {
        size_t len;
        void *r;

        len = strlen(ptr);

        if (qmark) {
            /* still in quotated text */
            /* remove NULL termination of the previous token since it is not a token,
             * but a part of the quotation string */
            ptr[-1] = ' ';

            if ((ptr[len - 1] == qmark) && (ptr[len - 2] != '\\')) {
                /* end of quotation */
                qmark = 0;
                /* shorten the argument by the terminating quotation mark */
                ptr[len - 1] = '\0';
            }
            continue;
        }

        /* another token in cmdline */
        ++count;
        r = realloc(vector, (count + 1) * sizeof *vector);
        if (!r) {
            YLMSG_E("Memory allocation failed (%s:%d, %s).\n", __FILE__, __LINE__, strerror(errno));
            free(vector);
            return -1;
        }
        vector = r;
        vector[count - 1] = ptr;

        if ((ptr[0] == '"') || (ptr[0] == '\'')) {
            /* remember the quotation mark to identify end of quotation */
            qmark = ptr[0];

            /* move the remembered argument after the quotation mark */
            ++vector[count - 1];

            /* check if the quotation is terminated within this token */
            if ((ptr[len - 1] == qmark) && (ptr[len - 2] != '\\')) {
                /* end of quotation */
                qmark = 0;
                /* shorten the argument by the terminating quotation mark */
                ptr[len - 1] = '\0';
            }
        }
    }
    vector[count] = NULL;

    *argc_p = count;
    *argv_p = vector;

    return 0;
}

int
get_format(const char *filename, LYS_INFORMAT *schema, LYD_FORMAT *data)
{
    char *ptr;
    LYS_INFORMAT informat_s;
    LYD_FORMAT informat_d;

    /* get the file format */
    if ((ptr = strrchr(filename, '.')) != NULL) {
        ++ptr;
        if (!strcmp(ptr, "yang")) {
            informat_s = LYS_IN_YANG;
            informat_d = 0;
        } else if (!strcmp(ptr, "yin")) {
            informat_s = LYS_IN_YIN;
            informat_d = 0;
        } else if (!strcmp(ptr, "xml")) {
            informat_s = 0;
            informat_d = LYD_XML;
        } else if (!strcmp(ptr, "json")) {
            informat_s = 0;
            informat_d = LYD_JSON;
        } else if (!strcmp(ptr, "lyb")) {
            informat_s = 0;
            informat_d = LYD_LYB;
        } else {
            YLMSG_E("Input file \"%s\" in an unknown format \"%s\".\n", filename, ptr);
            return 0;
        }
    } else {
        YLMSG_E("Input file \"%s\" without file extension - unknown format.\n", filename);
        return 1;
    }

    if (informat_d) {
        if (!data) {
            YLMSG_E("Input file \"%s\" not expected to contain data instances (unexpected format).\n", filename);
            return 2;
        }
        (*data) = informat_d;
    } else if (informat_s) {
        if (!schema) {
            YLMSG_E("Input file \"%s\" not expected to contain schema definition (unexpected format).\n", filename);
            return 3;
        }
        (*schema) = informat_s;
    }

    return 0;
}

int
print_list(struct ly_out *out, struct ly_ctx *ctx, LYD_FORMAT outformat)
{
    struct lyd_node *ylib;
    uint32_t idx = 0, has_modules = 0;
    const struct lys_module *mod;

    if (outformat != LYD_UNKNOWN) {
        if (ly_ctx_get_yanglib_data(ctx, &ylib, "%u", ly_ctx_get_change_count(ctx))) {
            YLMSG_E("Getting context info (ietf-yang-library data) failed. If the YANG module is missing or not implemented, use an option to add it internally.\n");
            return 1;
        }

        lyd_print_all(out, ylib, outformat, 0);
        lyd_free_all(ylib);
        return 0;
    }

    /* iterate schemas in context and provide just the basic info */
    ly_print(out, "List of the loaded models:\n");
    while ((mod = ly_ctx_get_module_iter(ctx, &idx))) {
        has_modules++;

        /* conformance print */
        if (mod->implemented) {
            ly_print(out, "    I");
        } else {
            ly_print(out, "    i");
        }

        /* module print */
        ly_print(out, " %s", mod->name);
        if (mod->revision) {
            ly_print(out, "@%s", mod->revision);
        }

        /* submodules print */
        if (mod->parsed && mod->parsed->includes) {
            uint64_t u = 0;
            ly_print(out, " (");
            LY_ARRAY_FOR(mod->parsed->includes, u) {
                ly_print(out, "%s%s", !u ? "" : ",", mod->parsed->includes[u].name);
                if (mod->parsed->includes[u].rev[0]) {
                    ly_print(out, "@%s", mod->parsed->includes[u].rev);
                }
            }
            ly_print(out, ")");
        }

        /* finish the line */
        ly_print(out, "\n");
    }

    if (!has_modules) {
        ly_print(out, "\t(none)\n");
    }

    ly_print_flush(out);
    return 0;
}

int
evaluate_xpath(const struct lyd_node *tree, const char *xpath)
{
    struct ly_set *set = NULL;

    if (lyd_find_xpath(tree, xpath, &set)) {
        return -1;
    }

    /* print result */
    printf("XPath \"%s\" evaluation result:\n", xpath);
    if (!set->count) {
        printf("\tEmpty\n");
    } else {
        for (uint32_t u = 0; u < set->count; ++u) {
            struct lyd_node *node = (struct lyd_node *)set->objs[u];
            printf("  %s \"%s\"", lys_nodetype2str(node->schema->nodetype), node->schema->name);
            if (node->schema->nodetype & (LYS_LEAF | LYS_LEAFLIST)) {
                printf(" (value: \"%s\")\n", lyd_get_value(node));
            } else if (node->schema->nodetype == LYS_LIST) {
                printf(" (");
                for (struct lyd_node *key = ((struct lyd_node_inner *)node)->child; key && lysc_is_key(key->schema); key = key->next) {
                    printf("%s\"%s\": \"%s\";", (key != ((struct lyd_node_inner *)node)->child) ? " " : "",
                            key->schema->name, lyd_get_value(key));
                }
                printf(")\n");
            }
        }
    }

    ly_set_free(set, NULL);
    return 0;
}

LY_ERR
process_data(struct ly_ctx *ctx, enum lyd_type data_type, uint8_t merge, LYD_FORMAT format, struct ly_out *out,
        uint32_t options_parse, uint32_t options_validate, uint32_t options_print,
        struct cmdline_file *operational_f, struct ly_set *inputs, struct ly_set *xpaths)
{
    LY_ERR ret = LY_SUCCESS;
    struct lyd_node *tree = NULL, *merged_tree = NULL;
    struct lyd_node *operational = NULL;

    /* additional operational datastore */
    if (operational_f && operational_f->in) {
        ret = lyd_parse_data(ctx, NULL, operational_f->in, operational_f->format, LYD_PARSE_ONLY, 0, &operational);
        if (ret) {
            YLMSG_E("Failed to parse operational datastore file \"%s\".\n", operational_f->path);
            goto cleanup;
        }
    }

    for (uint32_t u = 0; u < inputs->count; ++u) {
        struct cmdline_file *input_f = (struct cmdline_file *)inputs->objs[u];
        switch (data_type) {
        case LYD_TYPE_DATA_YANG:
            ret = lyd_parse_data(ctx, NULL, input_f->in, input_f->format, options_parse, options_validate, &tree);
            break;
        case LYD_TYPE_RPC_YANG:
        case LYD_TYPE_REPLY_YANG:
        case LYD_TYPE_NOTIF_YANG:
            ret = lyd_parse_op(ctx, NULL, input_f->in, input_f->format, data_type, &tree, NULL);
            break;
        default:
            YLMSG_E("Internal error (%s:%d).\n", __FILE__, __LINE__);
            goto cleanup;
        }

        if (ret) {
            YLMSG_E("Failed to parse input data file \"%s\".\n", input_f->path);
            goto cleanup;
        }

        if (merge) {
            /* merge the data so far parsed for later validation and print */
            if (!merged_tree) {
                merged_tree = tree;
            } else {
                ret = lyd_merge_siblings(&merged_tree, tree, LYD_MERGE_DESTRUCT);
                if (ret) {
                    YLMSG_E("Merging %s with previous data failed.\n", input_f->path);
                    goto cleanup;
                }
            }
            tree = NULL;
        } else if (format) {
            lyd_print_all(out, tree, format, options_print);
        } else if (operational) {
            /* additional validation of the RPC/Action/reply/Notification with the operational datastore */
            ret = lyd_validate_op(tree, operational, data_type, NULL);
            if (ret) {
                YLMSG_E("Failed to validate input data file \"%s\" with operational datastore \"%s\".\n",
                        input_f->path, operational_f->path);
                goto cleanup;
            }
        }
        lyd_free_all(tree);
        tree = NULL;
    }

    if (merge) {
        /* validate the merged result */
        ret = lyd_validate_all(&merged_tree, ctx, LYD_VALIDATE_PRESENT, NULL);
        if (ret) {
            YLMSG_E("Merged data are not valid.\n");
            goto cleanup;
        }

        if (format) {
            /* and print it */
            lyd_print_all(out, merged_tree, format, options_print);
        }

        for (uint32_t u = 0; u < xpaths->count; ++u) {
            if (evaluate_xpath(merged_tree, (const char *)xpaths->objs[u])) {
                goto cleanup;
            }
        }
    }

cleanup:
    /* cleanup */
    lyd_free_all(merged_tree);
    lyd_free_all(tree);

    return ret;
}