/*
 * QuickJS Javascript Engine
 *
 * Copyright (c) 2017-2021 Fabrice Bellard
 * Copyright (c) 2017-2021 Charlie Gordon
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "libc/fmt/fmt.h"
#include "third_party/quickjs/internal.h"
#include "third_party/quickjs/leb128.h"
#include "third_party/quickjs/libregexp.h"
#include "third_party/quickjs/quickjs.h"

asm(".ident\t\"\\n\\n\
QuickJS (MIT License)\\n\
Copyright (c) 2017-2021 Fabrice Bellard\\n\
Copyright (c) 2017-2021 Charlie Gordon\"");
asm(".include \"libc/disclaimer.inc\"");
/* clang-format off */

int js_parse_error(JSParseState *s, const char *fmt, ...)
{
    JSContext *ctx = s->ctx;
    va_list ap;
    int backtrace_flags;
    va_start(ap, fmt);
    JS_ThrowError2(ctx, JS_SYNTAX_ERROR, fmt, ap, FALSE);
    va_end(ap);
    backtrace_flags = 0;
    if (s->cur_func && s->cur_func->backtrace_barrier)
        backtrace_flags = JS_BACKTRACE_FLAG_SINGLE_LEVEL;
    build_backtrace(ctx, ctx->rt->current_exception, s->filename, s->line_num,
                    backtrace_flags);
    return -1;
}

JSValue JS_NewError(JSContext *ctx)
{
    return JS_NewObjectClass(ctx, JS_CLASS_ERROR);
}

JSValue JS_ThrowError2(JSContext *ctx, JSErrorEnum error_num, const char *fmt, va_list ap, BOOL add_backtrace)
{
    char buf[256];
    JSValue obj, ret;
    vsnprintf(buf, sizeof(buf), fmt, ap);
    obj = JS_NewObjectProtoClass(ctx, ctx->native_error_proto[error_num],
                                 JS_CLASS_ERROR);
    if (UNLIKELY(JS_IsException(obj))) {
        /* out of memory: throw JS_NULL to avoid recursing */
        obj = JS_NULL;
    } else {
        JS_DefinePropertyValue(ctx, obj, JS_ATOM_message,
                               JS_NewString(ctx, buf),
                               JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
    }
    if (add_backtrace) {
        build_backtrace(ctx, obj, NULL, 0, 0);
    }
    ret = JS_Throw(ctx, obj);
    return ret;
}

JSValue JS_ThrowError(JSContext *ctx, JSErrorEnum error_num, const char *fmt, va_list ap)
{
    JSRuntime *rt = ctx->rt;
    JSStackFrame *sf;
    BOOL add_backtrace;
    /* the backtrace is added later if called from a bytecode function */
    sf = rt->current_stack_frame;
    add_backtrace = !rt->in_out_of_memory &&
        (!sf || (JS_GetFunctionBytecode(sf->cur_func) == NULL));
    return JS_ThrowError2(ctx, error_num, fmt, ap, add_backtrace);
}

JSValue JS_ThrowSyntaxError(JSContext *ctx, const char *fmt, ...)
{
    JSValue val;
    va_list ap;
    va_start(ap, fmt);
    val = JS_ThrowError(ctx, JS_SYNTAX_ERROR, fmt, ap);
    va_end(ap);
    return val;
}

JSValue JS_ThrowTypeError(JSContext *ctx, const char *fmt, ...)
{
    JSValue val;
    va_list ap;
    va_start(ap, fmt);
    val = JS_ThrowError(ctx, JS_TYPE_ERROR, fmt, ap);
    va_end(ap);
    return val;
}

int JS_ThrowTypeErrorOrFalse(JSContext *ctx, int flags, const char *fmt, ...)
{
    va_list ap;
    if ((flags & JS_PROP_THROW) ||
        ((flags & JS_PROP_THROW_STRICT) && is_strict_mode(ctx))) {
        va_start(ap, fmt);
        JS_ThrowError(ctx, JS_TYPE_ERROR, fmt, ap);
        va_end(ap);
        return -1;
    } else {
        return FALSE;
    }
}

/* never use it directly */
JSValue __JS_ThrowTypeErrorAtom(JSContext *ctx, JSAtom atom, const char *fmt, ...)
{
    char buf[ATOM_GET_STR_BUF_SIZE];
    return JS_ThrowTypeError(ctx, fmt,
                             JS_AtomGetStr(ctx, buf, sizeof(buf), atom));
}

/* never use it directly */
JSValue __JS_ThrowSyntaxErrorAtom(JSContext *ctx, JSAtom atom, const char *fmt, ...)
{
    char buf[ATOM_GET_STR_BUF_SIZE];
    return JS_ThrowSyntaxError(ctx, fmt,
                             JS_AtomGetStr(ctx, buf, sizeof(buf), atom));
}

int JS_ThrowTypeErrorReadOnly(JSContext *ctx, int flags, JSAtom atom)
{
    if ((flags & JS_PROP_THROW) ||
        ((flags & JS_PROP_THROW_STRICT) && is_strict_mode(ctx))) {
        JS_ThrowTypeErrorAtom(ctx, "'%s' is read-only", atom);
        return -1;
    } else {
        return FALSE;
    }
}

JSValue JS_ThrowReferenceError(JSContext *ctx, const char *fmt, ...)
{
    JSValue val;
    va_list ap;
    va_start(ap, fmt);
    val = JS_ThrowError(ctx, JS_REFERENCE_ERROR, fmt, ap);
    va_end(ap);
    return val;
}

JSValue JS_ThrowRangeError(JSContext *ctx, const char *fmt, ...)
{
    JSValue val;
    va_list ap;
    va_start(ap, fmt);
    val = JS_ThrowError(ctx, JS_RANGE_ERROR, fmt, ap);
    va_end(ap);
    return val;
}

JSValue JS_ThrowInternalError(JSContext *ctx, const char *fmt, ...)
{
    JSValue val;
    va_list ap;
    va_start(ap, fmt);
    val = JS_ThrowError(ctx, JS_INTERNAL_ERROR, fmt, ap);
    va_end(ap);
    return val;
}

JSValue JS_ThrowOutOfMemory(JSContext *ctx)
{
    JSRuntime *rt = ctx->rt;
    if (!rt->in_out_of_memory) {
        rt->in_out_of_memory = TRUE;
        JS_ThrowInternalError(ctx, "out of memory");
        rt->in_out_of_memory = FALSE;
    }
    return JS_EXCEPTION;
}

JSValue JS_ThrowStackOverflow(JSContext *ctx)
{
    return JS_ThrowInternalError(ctx, "stack overflow");
}

JSValue JS_ThrowTypeErrorNotAnObject(JSContext *ctx)
{
    return JS_ThrowTypeError(ctx, "not an object");
}

JSValue JS_ThrowTypeErrorNotASymbol(JSContext *ctx)
{
    return JS_ThrowTypeError(ctx, "not a symbol");
}

int js_throw_URIError(JSContext *ctx, const char *fmt, ...)
{
    va_list ap;
    va_start(ap, fmt);
    JS_ThrowError(ctx, JS_URI_ERROR, fmt, ap);
    va_end(ap);
    return -1;
}

JSValue JS_ThrowReferenceErrorNotDefined(JSContext *ctx, JSAtom name)
{
    char buf[ATOM_GET_STR_BUF_SIZE];
    return JS_ThrowReferenceError(ctx, "'%s' is not defined",
                                  JS_AtomGetStr(ctx, buf, sizeof(buf), name));
}

JSValue JS_ThrowReferenceErrorUninitialized(JSContext *ctx, JSAtom name)
{
    char buf[ATOM_GET_STR_BUF_SIZE];
    return JS_ThrowReferenceError(ctx, "%s is not initialized",
                                  name == JS_ATOM_NULL ? "lexical variable" :
                                  JS_AtomGetStr(ctx, buf, sizeof(buf), name));
}

JSValue JS_ThrowReferenceErrorUninitialized2(JSContext *ctx,
                                             JSFunctionBytecode *b,
                                             int idx, BOOL is_ref)
{
    JSAtom atom = JS_ATOM_NULL;
    if (is_ref) {
        atom = b->closure_var[idx].var_name;
    } else {
        /* not present if the function is stripped and contains no eval() */
        if (b->vardefs)
            atom = b->vardefs[b->arg_count + idx].var_name;
    }
    return JS_ThrowReferenceErrorUninitialized(ctx, atom);
}

JSValue JS_ThrowSyntaxErrorVarRedeclaration(JSContext *ctx, JSAtom prop)
{
    return JS_ThrowSyntaxErrorAtom(ctx, "redeclaration of '%s'", prop);
}

JSValue JS_ThrowTypeErrorPrivateNotFound(JSContext *ctx, JSAtom atom)
{
    return JS_ThrowTypeErrorAtom(ctx, "private class field '%s' does not exist",
                                 atom);
}

JSValue JS_ThrowTypeErrorDetachedArrayBuffer(JSContext *ctx)
{
    return JS_ThrowTypeError(ctx, "ArrayBuffer is detached");
}

/* in order to avoid executing arbitrary code during the stack trace
   generation, we only look at simple 'name' properties containing a
   string. */
static const char *get_func_name(JSContext *ctx, JSValueConst func)
{
    JSProperty *pr;
    JSShapeProperty *prs;
    JSValueConst val;
    if (JS_VALUE_GET_TAG(func) != JS_TAG_OBJECT)
        return NULL;
    prs = find_own_property(&pr, JS_VALUE_GET_OBJ(func), JS_ATOM_name);
    if (!prs)
        return NULL;
    if ((prs->flags & JS_PROP_TMASK) != JS_PROP_NORMAL)
        return NULL;
    val = pr->u.value;
    if (JS_VALUE_GET_TAG(val) != JS_TAG_STRING)
        return NULL;
    return JS_ToCString(ctx, val);
}

int find_line_num(JSContext *ctx, JSFunctionBytecode *b, uint32_t pc_value)
{
    const uint8_t *p_end, *p;
    int new_line_num, line_num, pc, v, ret;
    unsigned int op;
    if (!b->has_debug || !b->debug.pc2line_buf) {
        /* function was stripped */
        return -1;
    }
    p = b->debug.pc2line_buf;
    p_end = p + b->debug.pc2line_len;
    pc = 0;
    line_num = b->debug.line_num;
    while (p < p_end) {
        op = *p++;
        if (op == 0) {
            uint32_t val;
            ret = get_leb128(&val, p, p_end);
            if (ret < 0)
                goto fail;
            pc += val;
            p += ret;
            ret = get_sleb128(&v, p, p_end);
            if (ret < 0) {
            fail:
                /* should never happen */
                return b->debug.line_num;
            }
            p += ret;
            new_line_num = line_num + v;
        } else {
            op -= PC2LINE_OP_FIRST;
            pc += (op / PC2LINE_RANGE);
            new_line_num = line_num + (op % PC2LINE_RANGE) + PC2LINE_BASE;
        }
        if (pc_value < pc)
            return line_num;
        line_num = new_line_num;
    }
    return line_num;
}

/* if filename != NULL, an additional level is added with the filename
   and line number information (used for parse error). */
void build_backtrace(JSContext *ctx, JSValueConst error_obj,
                     const char *filename, int line_num,
                     int backtrace_flags)
{
    JSStackFrame *sf;
    JSValue str;
    DynBuf dbuf;
    const char *func_name_str;
    const char *str1;
    JSObject *p;
    BOOL backtrace_barrier;
    js_dbuf_init(ctx, &dbuf);
    if (filename) {
        dbuf_printf(&dbuf, "    at %s", filename);
        if (line_num != -1)
            dbuf_printf(&dbuf, ":%d", line_num);
        dbuf_putc(&dbuf, '\n');
        str = JS_NewString(ctx, filename);
        JS_DefinePropertyValue(ctx, error_obj, JS_ATOM_fileName, str,
                               JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
        JS_DefinePropertyValue(ctx, error_obj, JS_ATOM_lineNumber, JS_NewInt32(ctx, line_num),
                               JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
        if (backtrace_flags & JS_BACKTRACE_FLAG_SINGLE_LEVEL)
            goto done;
    }
    for(sf = ctx->rt->current_stack_frame; sf != NULL; sf = sf->prev_frame) {
        if (backtrace_flags & JS_BACKTRACE_FLAG_SKIP_FIRST_LEVEL) {
            backtrace_flags &= ~JS_BACKTRACE_FLAG_SKIP_FIRST_LEVEL;
            continue;
        }
        func_name_str = get_func_name(ctx, sf->cur_func);
        if (!func_name_str || func_name_str[0] == '\0')
            str1 = "<anonymous>";
        else
            str1 = func_name_str;
        dbuf_printf(&dbuf, "    at %s", str1);
        JS_FreeCString(ctx, func_name_str);
        p = JS_VALUE_GET_OBJ(sf->cur_func);
        backtrace_barrier = FALSE;
        if (js_class_has_bytecode(p->class_id)) {
            JSFunctionBytecode *b;
            const char *atom_str;
            int line_num1;
            b = p->u.func.function_bytecode;
            backtrace_barrier = b->backtrace_barrier;
            if (b->has_debug) {
                line_num1 = find_line_num(ctx, b,
                                          sf->cur_pc - b->byte_code_buf - 1);
                atom_str = JS_AtomToCString(ctx, b->debug.filename);
                dbuf_printf(&dbuf, " (%s",
                            atom_str ? atom_str : "<null>");
                JS_FreeCString(ctx, atom_str);
                if (line_num1 != -1)
                    dbuf_printf(&dbuf, ":%d", line_num1);
                dbuf_putc(&dbuf, ')');
            }
        } else {
            dbuf_printf(&dbuf, " (native)");
        }
        dbuf_putc(&dbuf, '\n');
        /* stop backtrace if JS_EVAL_FLAG_BACKTRACE_BARRIER was used */
        if (backtrace_barrier)
            break;
    }
 done:
    dbuf_putc(&dbuf, '\0');
    if (dbuf_error(&dbuf))
        str = JS_NULL;
    else
        str = JS_NewString(ctx, (char *)dbuf.buf);
    dbuf_free(&dbuf);
    JS_DefinePropertyValue(ctx, error_obj, JS_ATOM_stack, str,
                           JS_PROP_WRITABLE | JS_PROP_CONFIGURABLE);
}

JSValue throw_bf_exception(JSContext *ctx, int status)
{
    const char *str;
    if (status & BF_ST_MEM_ERROR)
        return JS_ThrowOutOfMemory(ctx);
    if (status & BF_ST_DIVIDE_ZERO) {
        str = "division by zero";
    } else if (status & BF_ST_INVALID_OP) {
        str = "invalid operation";
    } else {
        str = "integer overflow";
    }
    return JS_ThrowRangeError(ctx, "%s", str);
}