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

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

#include "audit.h"
#include "config.h"
#include "db.h"
#include "sha256.h"
#include "util.h"

/* ------------------------------------------------------------------ */
/* attachments                                                         */
/* ------------------------------------------------------------------ */

static int link_attachment(struct req *r, int64_t aid, int64_t vid,
                           char **errmsg, const char **errcode)
{
    *errcode = "INTERNAL";
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "SELECT (SELECT count(*) FROM vouchers WHERE org_id=?1 AND id=?2),"
            "(SELECT count(*) FROM voucher_attachments WHERE org_id=?1"
            " AND voucher_id=?2 AND attachment_id=?3),"
            "(SELECT count(*) FROM attachments WHERE org_id=?1 AND id=?3)",
            -1, &st, NULL) != SQLITE_OK) {
        *errmsg = xstrdup("database error");
        return -1;
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_int64(st, 2, vid);
    sqlite3_bind_int64(st, 3, aid);
    int64_t vexists = 0, linked = 0, aexists = 0;
    if (sqlite3_step(st) == SQLITE_ROW) {
        vexists = sqlite3_column_int64(st, 0);
        linked = sqlite3_column_int64(st, 1);
        aexists = sqlite3_column_int64(st, 2);
    }
    sqlite3_finalize(st);
    if (!aexists) {
        *errmsg = xstrdup("attachment not found");
        *errcode = "NOT_FOUND";
        return -1;
    }
    if (!vexists) {
        *errmsg = xstrdup("voucher not found");
        *errcode = "NOT_FOUND";
        return -1;
    }
    if (linked) {
        *errmsg = xstrdup("attachment is already linked");
        *errcode = "CONFLICT";
        return -1;
    }
    char ts[32];
    util_iso8601(util_now(), ts, sizeof ts);
    if (sqlite3_prepare_v2(
            r->db,
            "INSERT INTO voucher_attachments(org_id,voucher_id,attachment_id,"
            "created_at) VALUES(?1,?2,?3,?4)",
            -1, &st, NULL) != SQLITE_OK) {
        *errmsg = xstrdup("database error");
        return -1;
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_int64(st, 2, vid);
    sqlite3_bind_int64(st, 3, aid);
    sqlite3_bind_text(st, 4, ts, -1, SQLITE_TRANSIENT);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    if (rc != SQLITE_DONE) {
        *errmsg = xstrdup("could not link attachment");
        return -1;
    }
    return 0;
}

static yyjson_mut_val *h_attachment_put(struct req *r)
{
    const char *filename = arg_str(r->args, "filename");
    const char *mime = arg_str(r->args, "mime");
    const char *b64 = arg_str(r->args, "content_base64");
    int64_t voucher_id = 0;
    arg_int(r->args, "voucher_id", &voucher_id);
    if (!filename || !*filename || !b64)
        return fail(r, "INVALID_ARGS",
                    "filename and content_base64 are required");
    if (!mime || !*mime)
        mime = "application/octet-stream";
    unsigned char *content = NULL;
    size_t len = 0;
    if (util_b64_decode(b64, strlen(b64), &content, &len) != 0)
        return fail(r, "INVALID_ARGS", "content_base64 is not valid base64");
    if ((long)len > g_cfg.max_attachment_bytes) {
        free(content);
        return failf(r, "TOO_LARGE", "attachment exceeds %ld bytes",
                     g_cfg.max_attachment_bytes);
    }
    unsigned char hash[32];
    util_sha256(content, len, hash);
    char ts[32];
    util_iso8601(util_now(), ts, sizeof ts);

    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "SELECT id FROM attachments WHERE org_id=?1 AND sha256=?2"
            " AND filename=?3",
            -1, &st, NULL) != SQLITE_OK) {
        free(content);
        return db_error(r);
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_blob(st, 2, hash, 32, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 3, filename, -1, SQLITE_TRANSIENT);
    int64_t existing = 0;
    if (sqlite3_step(st) == SQLITE_ROW)
        existing = sqlite3_column_int64(st, 0);
    sqlite3_finalize(st);

    if (existing) {
        free(content);
        if (voucher_id) {
            char *emsg = NULL;
            const char *ecode = NULL;
            if (link_attachment(r, existing, voucher_id, &emsg, &ecode) != 0) {
                yyjson_mut_val *res =
                    fail(r, ecode ? ecode : "INTERNAL", emsg);
                free(emsg);
                return res;
            }
            char *reqjson = audit_args_json(r->args);
            audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                         "attachment.link", reqjson, "OK", NULL);
            free(reqjson);
        }
        yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
        yyjson_mut_obj_add_int(r->rdoc, o, "id", existing);
        yyjson_mut_obj_add_bool(r->rdoc, o, "replayed", true);
        return o;
    }

    if (sqlite3_prepare_v2(
            r->db,
            "INSERT INTO attachments(org_id,sha256,filename,mime,size_bytes,"
            "content,created_at,created_by) VALUES(?1,?2,?3,?4,?5,?6,?7,?8)",
            -1, &st, NULL) != SQLITE_OK) {
        free(content);
        return db_error(r);
    }
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_blob(st, 2, hash, 32, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 3, filename, -1, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 4, mime, -1, SQLITE_TRANSIENT);
    sqlite3_bind_int64(st, 5, (int64_t)len);
    sqlite3_bind_blob(st, 6, content, (int)len, SQLITE_TRANSIENT);
    sqlite3_bind_text(st, 7, ts, -1, SQLITE_TRANSIENT);
    sqlite3_bind_int64(st, 8, r->sess->user_id);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    free(content);
    if (rc != SQLITE_DONE)
        return db_sqlite_error(r);
    int64_t id = db_last_id(r->db);

    if (voucher_id) {
        char *emsg = NULL;
        const char *ecode = NULL;
        if (link_attachment(r, id, voucher_id, &emsg, &ecode) != 0) {
            yyjson_mut_val *res = fail(r, ecode ? ecode : "INTERNAL", emsg);
            free(emsg);
            return res;
        }
    }
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "attachment.put", reqjson, "OK", NULL);
    free(reqjson);
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "id", id);
    yyjson_mut_obj_add_int(r->rdoc, o, "size_bytes", (int64_t)len);
    return o;
}

static yyjson_mut_val *h_attachment_link(struct req *r)
{
    int64_t id = 0, voucher_id = 0;
    arg_int(r->args, "id", &id);
    arg_int(r->args, "voucher_id", &voucher_id);
    if (id <= 0 || voucher_id <= 0)
        return fail(r, "INVALID_ARGS", "id and voucher_id are required");
    if (r->dry_run) {
        yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
        yyjson_mut_obj_add_bool(r->rdoc, o, "dry_run", true);
        return o;
    }
    char *emsg = NULL;
    const char *ecode = NULL;
    if (link_attachment(r, id, voucher_id, &emsg, &ecode) != 0) {
        yyjson_mut_val *e = fail(r, ecode ? ecode : "INTERNAL", emsg);
        free(emsg);
        return e;
    }
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "attachment.link", reqjson, "OK", NULL);
    free(reqjson);
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "id", id);
    yyjson_mut_obj_add_int(r->rdoc, o, "voucher_id", voucher_id);
    return o;
}

static yyjson_mut_val *h_attachment_unlink(struct req *r)
{
    int64_t id = 0, voucher_id = 0;
    arg_int(r->args, "id", &id);
    arg_int(r->args, "voucher_id", &voucher_id);
    if (id <= 0 || voucher_id <= 0)
        return fail(r, "INVALID_ARGS", "id and voucher_id are required");
    if (r->dry_run) {
        yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
        yyjson_mut_obj_add_bool(r->rdoc, o, "dry_run", true);
        return o;
    }
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "DELETE FROM voucher_attachments WHERE org_id=?1"
            " AND voucher_id=?2 AND attachment_id=?3",
            -1, &st, NULL) != SQLITE_OK)
        return db_error(r);
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_int64(st, 2, voucher_id);
    sqlite3_bind_int64(st, 3, id);
    int rc = sqlite3_step(st);
    sqlite3_finalize(st);
    if (rc != SQLITE_DONE)
        return db_sqlite_error(r);
    if (sqlite3_changes(r->db) == 0)
        return fail(r, "NOT_FOUND", "link not found");
    char *reqjson = audit_args_json(r->args);
    audit_append(r->db, r->org_id, r->sess->user_id, r->sess->token_id,
                 "attachment.unlink", reqjson, "OK", NULL);
    free(reqjson);
    return yyjson_mut_obj(r->rdoc);
}

static yyjson_mut_val *h_attachment_get(struct req *r)
{
    int64_t id = 0;
    if (!arg_int(r->args, "id", &id) || id <= 0)
        return fail(r, "INVALID_ARGS", "id is required");
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "SELECT filename,mime,size_bytes,content,sha256,created_at"
            " FROM attachments WHERE org_id=?1 AND id=?2",
            -1, &st, NULL) != SQLITE_OK)
        return db_error(r);
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_int64(st, 2, id);
    if (sqlite3_step(st) != SQLITE_ROW) {
        sqlite3_finalize(st);
        return fail(r, "NOT_FOUND", "attachment not found");
    }
    const void *content = sqlite3_column_blob(st, 3);
    size_t len = (size_t)sqlite3_column_bytes(st, 3);
    char *b64 = util_b64(content ? content : (const unsigned char *)"", len);
    char hex[65];
    const void *hb = sqlite3_column_blob(st, 4);
    if (hb && sqlite3_column_bytes(st, 4) == 32)
        util_hex((const unsigned char *)hb, 32, hex);
    else
        hex[0] = '\0';
    yyjson_mut_val *o = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_int(r->rdoc, o, "id", id);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "filename",
                              sq(sqlite3_column_text(st, 0)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "mime",
                              sq(sqlite3_column_text(st, 1)));
    yyjson_mut_obj_add_int(r->rdoc, o, "size_bytes",
                           sqlite3_column_int64(st, 2));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "sha256", hex);
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "created_at",
                              sq(sqlite3_column_text(st, 5)));
    yyjson_mut_obj_add_strcpy(r->rdoc, o, "content_base64", b64);
    free(b64);
    sqlite3_finalize(st);
    return o;
}

static yyjson_mut_val *h_attachment_list(struct req *r)
{
    int64_t voucher_id = 0, cursor = 0, limit = 100;
    int unlinked = 0;
    arg_int(r->args, "voucher_id", &voucher_id);
    arg_int(r->args, "cursor", &cursor);
    arg_int(r->args, "limit", &limit);
    arg_bool(r->args, "unlinked", &unlinked);
    if (limit < 1)
        limit = 100;
    if (limit > 1000)
        limit = 1000;
    sqlite3_stmt *st = NULL;
    if (sqlite3_prepare_v2(
            r->db,
            "SELECT a.id,a.filename,a.mime,a.size_bytes,a.created_at,a.sha256,"
            "(SELECT va.voucher_id FROM voucher_attachments va"
            " WHERE va.org_id=a.org_id AND va.attachment_id=a.id"
            "   AND (?2=0 OR va.voucher_id=?2)"
            " ORDER BY va.voucher_id LIMIT 1)"
            " FROM attachments a WHERE a.org_id=?1"
            " AND (?2=0 OR EXISTS(SELECT 1 FROM voucher_attachments va2"
            "   WHERE va2.org_id=a.org_id AND va2.attachment_id=a.id"
            "   AND va2.voucher_id=?2))"
            " AND (?3=0 OR NOT EXISTS(SELECT 1 FROM voucher_attachments va3"
            "   WHERE va3.org_id=a.org_id AND va3.attachment_id=a.id))"
            " AND a.id>?4 ORDER BY a.id LIMIT ?5",
            -1, &st, NULL) != SQLITE_OK)
        return db_error(r);
    sqlite3_bind_int64(st, 1, r->org_id);
    sqlite3_bind_int64(st, 2, voucher_id);
    sqlite3_bind_int(st, 3, unlinked);
    sqlite3_bind_int64(st, 4, cursor);
    sqlite3_bind_int64(st, 5, limit);
    yyjson_mut_val *items = yyjson_mut_arr(r->rdoc);
    int64_t n = 0, last = cursor;
    while (sqlite3_step(st) == SQLITE_ROW) {
        n++;
        last = sqlite3_column_int64(st, 0);
        yyjson_mut_val *o = yyjson_mut_arr_add_obj(r->rdoc, items);
        yyjson_mut_obj_add_int(r->rdoc, o, "id", last);
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "filename",
                                  sq(sqlite3_column_text(st, 1)));
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "mime",
                                  sq(sqlite3_column_text(st, 2)));
        yyjson_mut_obj_add_int(r->rdoc, o, "size_bytes",
                               sqlite3_column_int64(st, 3));
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "created_at",
                                  sq(sqlite3_column_text(st, 4)));
        char hex[65];
        const void *hb = sqlite3_column_blob(st, 5);
        if (hb && sqlite3_column_bytes(st, 5) == 32)
            util_hex((const unsigned char *)hb, 32, hex);
        else
            hex[0] = '\0';
        yyjson_mut_obj_add_strcpy(r->rdoc, o, "sha256", hex);
        if (sqlite3_column_type(st, 6) == SQLITE_NULL)
            yyjson_mut_obj_add_null(r->rdoc, o, "voucher_id");
        else
            yyjson_mut_obj_add_int(r->rdoc, o, "voucher_id",
                                   sqlite3_column_int64(st, 6));
    }
    sqlite3_finalize(st);
    yyjson_mut_val *out = yyjson_mut_obj(r->rdoc);
    yyjson_mut_obj_add_val(r->rdoc, out, "items", items);
    if (n == limit)
        yyjson_mut_obj_add_int(r->rdoc, out, "next_cursor", last);
    else
        yyjson_mut_obj_add_null(r->rdoc, out, "next_cursor");
    return out;
}


static const struct cmd_arg args_attachment_put[] = {
    { "filename", ARG_STR, 1, NULL, NULL, "File name" },
    { "mime", ARG_STR, 0, "application/octet-stream", NULL, "MIME type" },
    { "content_base64", ARG_STR, 1, NULL, NULL, "File content, base64" },
    { "voucher_id", ARG_INT, 0, NULL, NULL, "Link to this voucher" },
};

static const struct cmd_arg args_attachment_link[] = {
    { "id", ARG_INT, 1, NULL, NULL, "Attachment id" },
    { "voucher_id", ARG_INT, 1, NULL, NULL, "Voucher id" },
};

static const struct cmd_arg args_attachment_unlink[] = {
    { "id", ARG_INT, 1, NULL, NULL, "Attachment id" },
    { "voucher_id", ARG_INT, 1, NULL, NULL, "Voucher id" },
};

static const struct cmd_arg args_attachment_get[] = {
    { "id", ARG_INT, 1, NULL, NULL, "Attachment id" },
};

static const struct cmd_arg args_attachment_list[] = {
    { "voucher_id", ARG_INT, 0, NULL, NULL,
      "Only attachments on this voucher" },
    { "unlinked", ARG_BOOL, 0, NULL, NULL,
      "Only unlinked attachments (inbox)" },
    { "cursor", ARG_INT, 0, NULL, NULL, "Cursor from next_cursor" },
    { "limit", ARG_INT, 0, "100", NULL, "Page size, 1-1000" },
};

const struct command g_cmd_attachments[] = {
    { "attachment.put", "Store an underlag (receipt, invoice)", PERM_WRITE, 1,
      1, 1, h_attachment_put, CMD_ARGS(args_attachment_put) },
    { "attachment.link", "Link an existing attachment to a voucher",
      PERM_WRITE, 1, 1, 1, h_attachment_link, CMD_ARGS(args_attachment_link) },
    { "attachment.unlink", "Remove an attachment link", PERM_WRITE, 1, 1, 1,
      h_attachment_unlink, CMD_ARGS(args_attachment_unlink) },
    { "attachment.get", "Fetch an attachment", PERM_READ, 1, 0, 0,
      h_attachment_get, CMD_ARGS(args_attachment_get) },
    { "attachment.list", "List attachments / inbox", PERM_READ, 1, 0, 0,
      h_attachment_list, CMD_ARGS(args_attachment_list) },
};

const struct cmd_table g_cmd_table_attachments = {
    g_cmd_attachments, sizeof g_cmd_attachments / sizeof g_cmd_attachments[0]
};