#include "commands.h"
#include "cmd_util.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "audit.h"
#include "db.h"
#include "formula.h"
#include "util.h"

/* ------------------------------------------------------------------ */
/* voucher templates (konteringsmallar)                                */
/* ------------------------------------------------------------------ */

struct tpl_row_in {
    int64_t account_id;
    char account[16];
    char formula[256];
    char desc[128];
};
static int parse_template_rows(struct req *r, yyjson_val *rowsv,
                               struct tpl_row_in **out, size_t *out_n)
{
    *out = NULL;
    *out_n = 0;
    if (!rowsv || !yyjson_is_arr(rowsv))
        return fail(r, "INVALID_ARGS", "rows must be an array") ? -1 : -1;
    size_t n = yyjson_arr_size(rowsv);
    if (n == 0 || n > 100)
        return fail(r, "INVALID_ARGS",
                    "a template needs between 1 and 100 rows")
                   ? -1
                   : -1;
    struct tpl_row_in *rows = xcalloc(n, sizeof *rows);
    size_t k = 0;
    yyjson_arr_iter it = yyjson_arr_iter_with(rowsv);
    yyjson_val *item;
    while ((item = yyjson_arr_iter_next(&it))) {
        if (!yyjson_is_obj(item)) {
            free(rows);
            fail(r, "INVALID_ARGS", "each row must be an object");
            return -1;
        }
        yyjson_val *av = yyjson_obj_get(item, "account");
        yyjson_val *fv = yyjson_obj_get(item, "formula");
        if (!av || !yyjson_is_str(av) || !fv || !yyjson_is_str(fv)) {
            free(rows);
            failf(r, "INVALID_ARGS",
                  "row %zu: account and formula are required", k + 1);
            return -1;
        }
        const char *account = yyjson_get_str(av);
        const char *formula = yyjson_get_str(fv);
        if (!formula_valid(formula)) {
            free(rows);
            failf(r, "INVALID_ARGS", "row %zu: ogiltig formel '%s'", k + 1,
                  formula);
            return -1;
        }
        sqlite3_stmt *st = NULL;
        if (sqlite3_prepare_v2(r->db,
                               "SELECT id FROM accounts WHERE org_id=?1"
                               " AND number=?2",
                               -1, &st, NULL) != SQLITE_OK) {
            free(rows);
            return fail(r, "INTERNAL", "database error") ? -1 : -1;
        }
        sqlite3_bind_int64(st, 1, r->org_id);
        sqlite3_bind_text(st, 2, account, -1, SQLITE_TRANSIENT);
        if (sqlite3_step(st) != SQLITE_ROW) {
            sqlite3_finalize(st);
            free(rows);
            failf(r, "ACCOUNT_NOT_FOUND", "row %zu: account %s does not exist",
                  k + 1, account);
            return -1;
        }
        rows[k].account_id = sqlite3_column_int64(st, 0);
        sqlite3_finalize(st);
        snprintf(rows[k].account, sizeof rows[k].account, "%s", account);
        snprintf(rows[k].formula, sizeof rows[k].formula, "%s", formula);
        yyjson_val *dv = yyjson_obj_get(item, "description");
        if (dv && yyjson_is_str(dv))
            snprintf(rows[k].desc, sizeof rows[k].desc, "%s",
                     yyjson_get_str(dv));
        k++;
    }
    *out = rows;
    *out_n = k;
    return 0;
}

static yyjson_mut_val *tpl_rows_json(struct req *r, sqlite3_stmt *st)
{
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "line_no", sqlite3_column_int64(st, 0));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "account",
                              sq(sqlite3_column_text(st, 1)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "name",
                              sq(sqlite3_column_text(st, 2)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "formula",
                              sq(sqlite3_column_text(st, 3)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "description",
                              sq(sqlite3_column_text(st, 4)));
    return o;
}

static yyjson_mut_val *h_template_list(struct req *r)
{
    int active_only = 0;
    arg_bool(r->args, "active_only", &active_only);
    yyjson_mut_val *items = yyjson_mut_arr(r->rdoc);
    sqlite3_stmt *st = NULL;
    const char *sql =
        active_only
            ? "SELECT t.id,t.name,t.series,t.description,t.active,"
              "(SELECT count(*) FROM voucher_template_rows tr"
              " WHERE tr.org_id=t.org_id AND tr.template_id=t.id)"
              " FROM voucher_templates t WHERE t.org_id=?1 AND t.active=1"
              " ORDER BY t.name"
            : "SELECT t.id,t.name,t.series,t.description,t.active,"
              "(SELECT count(*) FROM voucher_template_rows tr"
              " WHERE tr.org_id=t.org_id AND tr.template_id=t.id)"
              " FROM voucher_templates t WHERE t.org_id=?1 ORDER BY t.name";
    if (sqlite3_prepare_v2(r->db, sql, -1, &st, NULL) != SQLITE_OK)
        return fail(r, "INTERNAL", "database error");
    sqlite3_bind_int64(st, 1, r->org_id);
    while (sqlite3_step(st) == SQLITE_ROW) {
        yyjson_mut_val *o = yyjson_mut_arr_add_obj(r->rdoc, items);
        yyjson_mut_obj_add_int(r->rdoc, o, "id", sqlite3_column_int64(st, 0));
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "name",
                                  sq(sqlite3_column_text(st, 1)));
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "series",
                                  sq(sqlite3_column_text(st, 2)));
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "description",
                                  sq(sqlite3_column_text(st, 3)));
        yyjson_mut_obj_add_bool(r->rdoc, o, "active",
                                sqlite3_column_int(st, 4) != 0);
        yyjson_mut_obj_add_int(r->rdoc, o, "row_count",
                               sqlite3_column_int64(st, 5));
    }
    sqlite3_finalize(st);
    yyjson_mut_val *out = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_val(r->rdoc, out, "items", items);
    return out;
}

static yyjson_mut_val *h_template_get(struct req *r)
{
    int64_t id = 0;
    arg_int(r->args, "id", &id);
    const char *name = arg_str(r->args, "name");
    if (id <= 0 && !name)
        return fail(r, "INVALID_ARGS", "id or name is required");
    sqlite3_stmt *st = NULL;
    const char *sql =
        id > 0 ? "SELECT id,name,series,description,active"
                 " FROM voucher_templates WHERE org_id=?1 AND id=?2"
               : "SELECT id,name,series,description,active"
                 " FROM voucher_templates WHERE org_id=?1 AND name=?2";
    if (sqlite3_prepare_v2(r->db, sql, -1, &st, NULL) != SQLITE_OK)
        return fail(r, "INTERNAL", "database error");
    sqlite3_bind_int64(st, 1, r->org_id);
    if (id > 0)
        sqlite3_bind_int64(st, 2, id);
    else
        sqlite3_bind_text(st, 2, name, -1, SQLITE_TRANSIENT);
    if (sqlite3_step(st) != SQLITE_ROW) {
        sqlite3_finalize(st);
        return fail(r, "NOT_FOUND", "template not found");
    }
    int64_t tpl = sqlite3_column_int64(st, 0);
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "id", tpl);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "name",
                              sq(sqlite3_column_text(st, 1)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "series",
                              sq(sqlite3_column_text(st, 2)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "description",
                              sq(sqlite3_column_text(st, 3)));
    yyjson_mut_obj_add_bool(r->rdoc, o, "active",
                            sqlite3_column_int(st, 4) != 0);
    sqlite3_finalize(st);

    yyjson_mut_val *rows = yyjson_mut_arr(r->rdoc);
    if (sqlite3_prepare_v2(
            r->db,
            "SELECT tr.line_no,a.number,a.name,tr.formula,"
            "COALESCE(tr.description,'') FROM voucher_template_rows tr"
            " JOIN accounts a ON a.org_id=tr.org_id AND a.id=tr.account_id"
            " WHERE tr.org_id=?1 AND tr.template_id=?2 ORDER BY tr.line_no",
            -1, &st, NULL) == SQLITE_OK) {
        sqlite3_bind_int64(st, 1, r->org_id);
        sqlite3_bind_int64(st, 2, tpl);
        while (sqlite3_step(st) == SQLITE_ROW)
            yyjson_mut_arr_add_val(rows, tpl_rows_json(r, st));
        sqlite3_finalize(st);
    }
    yyjson_mut_obj_add_val(r->rdoc, o, "rows", rows);
    return o;
}

static yyjson_mut_val *h_template_create(struct req *r)
{
    const char *name = arg_str(r->args, "name");
    const char *series = arg_str(r->args, "series");
    const char *description = arg_str(r->args, "description");
    if (!name || !*name)
        return fail(r, "INVALID_ARGS", "name is required");
    char *series_owned = NULL;
    if (!series || !*series) {
        series_owned = db_setting(r->db, r->org_id, "default_series");
        series = series_owned && *series_owned ? series_owned : "A";
    }
    if (!description)
        description = "";
    struct tpl_row_in *rows = NULL;
    size_t nrows = 0;
    if (parse_template_rows(
            r, r->args ? yyjson_obj_get(r->args, "rows") : NULL, &rows,
            &nrows) != 0)
        return NULL;

    if (r->dry_run) {
        yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "name", name);
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "series", series);
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "description", description);
        yyjson_mut_val *arr = yyjson_mut_arr(r->rdoc);
        for (size_t i = 0; i < nrows; i++) {
            yyjson_mut_val *ro = yyjson_mut_arr_add_obj(r->rdoc, arr);
            yyjson_mut_obj_add_strcpy(r->rdoc, ro, "account", rows[i].account);
            yyjson_mut_obj_add_strcpy(r->rdoc, ro, "formula", rows[i].formula);
            yyjson_mut_obj_add_strcpy(r->rdoc, ro, "description", rows[i].desc);
        }
        yyjson_mut_obj_add_val(r->rdoc, o, "rows", arr);
        yyjson_mut_obj_add_bool(r->rdoc, o, "dry_run", true);
        free(rows);
        free(series_owned);
        return o;
    }

    char ts[32];
    util_iso8601(util_now(), ts, sizeof ts);
    if (db_exec(r->db, "BEGIN IMMEDIATE", NULL) != 0) {
        free(rows);
        free(series_owned);
        return fail(r, "DB_BUSY", "could not start transaction");
    }
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(r->db,
                           "INSERT INTO voucher_templates(org_id,name,series,"
                           "description,created_at) VALUES(?1,?2,?3,?4,?5)",
                           -1, &st, NULL) != SQLITE_OK) {
        db_exec(r->db, "ROLLBACK", NULL);
        free(rows);
        return fail(r, "INTERNAL", "database error");
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_text(st, 2, name, -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 3, series, -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 4, description, -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 5, ts, -1, SQLITE_TRANSIENT);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    if (rc != SQLITE_DONE) {
        db_exec(r->db, "ROLLBACK", NULL);
        free(rows);
        if ((rc & 0xff) == SQLITE_CONSTRAINT)
            return fail(r, "CONFLICT", "a template with that name exists");
        return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
    }
    int64_t tpl = db_last_id(r->db);
    for (size_t i = 0; i < nrows; i++) {
        if (sqlite3_prepare_v2(
                r->db,
                "INSERT INTO voucher_template_rows(org_id,template_id,line_no,"
                "account_id,formula,description) VALUES(?1,?2,?3,?4,?5,?6)",
                -1, &st, NULL) != SQLITE_OK) {
            db_exec(r->db, "ROLLBACK", NULL);
            free(rows);
            return fail(r, "INTERNAL", "database error");
        }
        sqlite3_bind_int64(st, 1, r->org_id);
        sqlite3_bind_int64(st, 2, tpl);
        sqlite3_bind_int64(st, 3, (int64_t)i + 1);
        sqlite3_bind_int64(st, 4, rows[i].account_id);
        sqlite3_bind_text(st, 5, rows[i].formula, -1, SQLITE_TRANSIENT);
        if (rows[i].desc[0])
            sqlite3_bind_text(st, 6, rows[i].desc, -1, SQLITE_TRANSIENT);
        else
            sqlite3_bind_null(st, 6);
        rc = sqlite3_step(st);
        sqlite3_finalize(st);
        if (rc != SQLITE_DONE) {
            db_exec(r->db, "ROLLBACK", NULL);
            free(rows);
            return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
        }
    }
    free(rows);
    if (db_exec(r->db, "COMMIT", NULL) != 0)
        return fail(r, "INTERNAL", "commit failed");
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "template.create", reqjson, "OK", NULL);
    free(reqjson);
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "id", tpl);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "name", name);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "series", series);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "description", description);
    free(series_owned);
    return o;
}

static yyjson_mut_val *h_template_update(struct req *r)
{
    int64_t id = 0;
    arg_int(r->args, "id", &id);
    const char *name_arg = arg_str(r->args, "name");
    if (id <= 0 && !name_arg)
        return fail(r, "INVALID_ARGS", "id or name is required");
    struct tpl_head head;
    char *err = NULL;
    if (load_template(r->db, r->org_id, id, name_arg, &head, &err) != 0) {
        yyjson_mut_val *res =
            fail(r, "NOT_FOUND", err ? err : "template not found");
        free(err);
        return res;
    }
    const char *new_name = arg_str(r->args, "name");
    const char *series = arg_str(r->args, "series");
    const char *description = arg_str(r->args, "description");
    int active = -1;
    arg_bool(r->args, "active", &active);
    yyjson_val *rowsv = r->args ? yyjson_obj_get(r->args, "rows") : NULL;
    struct tpl_row_in *rows = NULL;
    size_t nrows = 0;
    if (rowsv) {
        if (parse_template_rows(r, rowsv, &rows, &nrows) != 0)
            return NULL;
    }
    if (!new_name && !series && !description && active < 0 && !rowsv) {
        free(rows);
        return fail(r, "INVALID_ARGS", "nothing to update");
    }

    if (r->dry_run) {
        free(rows);
        return h_template_get(r);
    }

    char ts[32];
    util_iso8601(util_now(), ts, sizeof ts);
    if (db_exec(r->db, "BEGIN IMMEDIATE", NULL) != 0) {
        free(rows);
        return fail(r, "DB_BUSY", "could not start transaction");
    }
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "UPDATE voucher_templates SET"
            " name=COALESCE(?2,name), series=COALESCE(?3,series),"
            " description=COALESCE(?4,description),"
            " active=CASE WHEN ?5<0 THEN active ELSE ?5 END, updated_at=?6"
            " WHERE org_id=?1 AND id=?7",
            -1, &st, NULL) != SQLITE_OK) {
        db_exec(r->db, "ROLLBACK", NULL);
        free(rows);
        return fail(r, "INTERNAL", "database error");
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    if (new_name)
        sqlite3_bind_text(st, 2, new_name, -1, SQLITE_TRANSIENT);
    else
        sqlite3_bind_null(st, 2);
    if (series)
        sqlite3_bind_text(st, 3, series, -1, SQLITE_TRANSIENT);
    else
        sqlite3_bind_null(st, 3);
    if (description)
        sqlite3_bind_text(st, 4, description, -1, SQLITE_TRANSIENT);
    else
        sqlite3_bind_null(st, 4);
    sqlite3_bind_int(st, 5, active);
    sqlite3_bind_text(st, 6, ts, -1, SQLITE_TRANSIENT);
    sqlite3_bind_int64(st, 7, head.id);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    if (rc != SQLITE_DONE) {
        db_exec(r->db, "ROLLBACK", NULL);
        free(rows);
        return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
    }
    if (rowsv) {
        if (sqlite3_prepare_v2(
                r->db,
                "DELETE FROM voucher_template_rows WHERE org_id=?1"
                " AND template_id=?2",
                -1, &st, NULL) != SQLITE_OK) {
            db_exec(r->db, "ROLLBACK", NULL);
            free(rows);
            return fail(r, "INTERNAL", "database error");
        }
        sqlite3_bind_int64(st, 1, r->org_id);
        sqlite3_bind_int64(st, 2, head.id);
        rc = sqlite3_step(st);
        sqlite3_finalize(st);
        if (rc != SQLITE_DONE) {
            db_exec(r->db, "ROLLBACK", NULL);
            free(rows);
            return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
        }
        for (size_t i = 0; i < nrows; i++) {
            if (sqlite3_prepare_v2(
                    r->db,
                    "INSERT INTO voucher_template_rows(org_id,template_id,"
                    "line_no,account_id,formula,description)"
                    " VALUES(?1,?2,?3,?4,?5,?6)",
                    -1, &st, NULL) != SQLITE_OK) {
                db_exec(r->db, "ROLLBACK", NULL);
                free(rows);
                return fail(r, "INTERNAL", "database error");
            }
            sqlite3_bind_int64(st, 1, r->org_id);
            sqlite3_bind_int64(st, 2, head.id);
            sqlite3_bind_int64(st, 3, (int64_t)i + 1);
            sqlite3_bind_int64(st, 4, rows[i].account_id);
            sqlite3_bind_text(st, 5, rows[i].formula, -1, SQLITE_TRANSIENT);
            if (rows[i].desc[0])
                sqlite3_bind_text(st, 6, rows[i].desc, -1, SQLITE_TRANSIENT);
            else
                sqlite3_bind_null(st, 6);
            rc = sqlite3_step(st);
            sqlite3_finalize(st);
            if (rc != SQLITE_DONE) {
                db_exec(r->db, "ROLLBACK", NULL);
                free(rows);
                return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
            }
        }
    }
    free(rows);
    if (db_exec(r->db, "COMMIT", NULL) != 0)
        return fail(r, "INTERNAL", "commit failed");
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "template.update", reqjson, "OK", NULL);
    free(reqjson);
    return h_template_get(r);
}

static yyjson_mut_val *h_template_archive(struct req *r)
{
    int64_t id = 0;
    arg_int(r->args, "id", &id);
    const char *name = arg_str(r->args, "name");
    if (id <= 0 && !name)
        return fail(r, "INVALID_ARGS", "id or name is required");
    sqlite3_stmt *st = NULL;
    const char *sql =
        id > 0 ? "UPDATE voucher_templates SET active=0 WHERE org_id=?1"
                 " AND id=?2"
               : "UPDATE voucher_templates SET active=0 WHERE org_id=?1"
                 " AND name=?2";
    if (sqlite3_prepare_v2(r->db, sql, -1, &st, NULL) != SQLITE_OK)
        return fail(r, "INTERNAL", "database error");
    sqlite3_bind_int64(st, 1, r->org_id);
    if (id > 0)
        sqlite3_bind_int64(st, 2, id);
    else
        sqlite3_bind_text(st, 2, name, -1, SQLITE_TRANSIENT);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    if (rc != SQLITE_DONE)
        return fail(r, "INTERNAL", sqlite3_errmsg(r->db));
    if (sqlite3_changes(r->db) == 0)
        return fail(r, "NOT_FOUND", "template not found");
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "template.archive", reqjson, "OK", NULL);
    free(reqjson);
    return yyjson_mut_obj(r->rdoc);
}


static const struct cmd_arg args_template_list[] = {
    { "active_only", ARG_BOOL, 0, NULL, NULL, "Only active templates" },
};

static const struct cmd_arg args_template_get[] = {
    { "id", ARG_INT, 0, NULL, NULL, "Template id" },
    { "name", ARG_STR, 0, NULL, NULL, "Template name" },
};

static const struct cmd_arg args_template_create[] = {
    { "name", ARG_STR, 1, NULL, NULL, "Template name" },
    { "series", ARG_STR, 0, NULL, NULL,
      "Number series; defaults to settings.default_series" },
    { "description", ARG_STR, 0, NULL, NULL,
      "Voucher text; {x} is replaced with the amount" },
    { "rows", ARG_JSON, 1, NULL, NULL,
      "Array of {account,formula,description?}" },
};

static const struct cmd_arg args_template_update[] = {
    { "id", ARG_INT, 0, NULL, NULL, "Template id" },
    { "name", ARG_STR, 0, NULL, NULL,
      "Template name, or the new name when id is given" },
    { "series", ARG_STR, 0, NULL, NULL, "Number series" },
    { "description", ARG_STR, 0, NULL, NULL, "Voucher text" },
    { "active", ARG_BOOL, 0, NULL, NULL, "Active flag" },
    { "rows", ARG_JSON, 0, NULL, NULL,
      "Replacement rows, {account,formula,description?}" },
};

static const struct cmd_arg args_template_archive[] = {
    { "id", ARG_INT, 0, NULL, NULL, "Template id" },
    { "name", ARG_STR, 0, NULL, NULL, "Template name" },
};

const struct command g_cmd_templates[] = {
    { "template.list", "List voucher templates", PERM_READ, 1, 0, 0,
      h_template_list, CMD_ARGS(args_template_list) },
    { "template.get", "Get a voucher template with its rows", PERM_READ, 1, 0,
      0, h_template_get, CMD_ARGS(args_template_get) },
    { "template.create", "Create a voucher template", PERM_WRITE, 1, 1, 1,
      h_template_create, CMD_ARGS(args_template_create) },
    { "template.update", "Update a voucher template", PERM_WRITE, 1, 1, 1,
      h_template_update, CMD_ARGS(args_template_update) },
    { "template.archive", "Archive a voucher template", PERM_WRITE, 1, 1, 1,
      h_template_archive, CMD_ARGS(args_template_archive) },
};

const struct cmd_table g_cmd_table_templates = {
    g_cmd_templates, sizeof g_cmd_templates / sizeof g_cmd_templates[0]
};