#ifndef DDEBUG
#define DDEBUG 0
#endif
#include "ddebug.h"

#include "ngx_http_lua_output.h"
#include "ngx_http_lua_util.h"
#include "ngx_http_lua_contentby.h"
#include <math.h>


static int ngx_http_lua_ngx_say(lua_State *L);
static int ngx_http_lua_ngx_print(lua_State *L);
static int ngx_http_lua_ngx_flush(lua_State *L);
static int ngx_http_lua_ngx_eof(lua_State *L);
static int ngx_http_lua_ngx_send_headers(lua_State *L);
static int ngx_http_lua_ngx_echo(lua_State *L, unsigned newline);
static void ngx_http_lua_flush_cleanup(void *data);


static int
ngx_http_lua_ngx_print(lua_State *L)
{
    dd("calling lua print");
    return ngx_http_lua_ngx_echo(L, 0);
}


static int
ngx_http_lua_ngx_say(lua_State *L)
{
    dd("calling");
    return ngx_http_lua_ngx_echo(L, 1);
}


static int
ngx_http_lua_ngx_echo(lua_State *L, unsigned newline)
{
    ngx_http_request_t          *r;
    ngx_http_lua_ctx_t          *ctx;
    const char                  *p;
    size_t                       len;
    size_t                       size;
    ngx_buf_t                   *b;
    ngx_chain_t                 *cl;
    ngx_int_t                    rc;
    int                          i;
    int                          nargs;
    int                          type;
    const char                  *msg;
    ngx_buf_tag_t                tag;

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "no request object found");
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);

    if (ctx == NULL) {
        return luaL_error(L, "no request ctx found");
    }

    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                               | NGX_HTTP_LUA_CONTEXT_ACCESS
                               | NGX_HTTP_LUA_CONTEXT_CONTENT);

    if (r->header_only) {
        return 0;
    }

    if (ctx->eof) {
        return luaL_error(L, "seen eof already");
    }

    nargs = lua_gettop(L);
    size = 0;

    for (i = 1; i <= nargs; i++) {

        type = lua_type(L, i);

        switch (type) {
            case LUA_TNUMBER:
            case LUA_TSTRING:

                lua_tolstring(L, i, &len);
                size += len;
                break;

            case LUA_TNIL:

                size += sizeof("nil") - 1;
                break;

            case LUA_TBOOLEAN:

                if (lua_toboolean(L, i)) {
                    size += sizeof("true") - 1;

                } else {
                    size += sizeof("false") - 1;
                }

                break;

            case LUA_TTABLE:

                size += ngx_http_lua_calc_strlen_in_table(L, i, i,
                                                          0 /* strict */);
                break;

            case LUA_TLIGHTUSERDATA:

                dd("userdata: %p", lua_touserdata(L, i));

                if (lua_touserdata(L, i) == NULL) {
                    size += sizeof("null") - 1;
                    break;
                }

                continue;

            default:

                msg = lua_pushfstring(L, "string, number, boolean, nil, "
                                      "ngx.null, or array table expected, "
                                      "but got %s", lua_typename(L, type));

                return luaL_argerror(L, i, msg);
        }
    }

    if (newline) {
        size += sizeof("\n") - 1;
    }

    if (size == 0) {
        /* do nothing for empty strings */
        return 0;
    }

    tag = (ngx_buf_tag_t) &ngx_http_lua_module;

    cl = ngx_http_lua_chains_get_free_buf(r->connection->log, r->pool,
                                          &ctx->free_bufs, size, tag);

    if (cl == NULL) {
        return luaL_error(L, "out of memory");
    }

    b = cl->buf;

    for (i = 1; i <= nargs; i++) {
        type = lua_type(L, i);
        switch (type) {
            case LUA_TNUMBER:
            case LUA_TSTRING:
                p = lua_tolstring(L, i, &len);
                b->last = ngx_copy(b->last, (u_char *) p, len);
                break;

            case LUA_TNIL:
                *b->last++ = 'n';
                *b->last++ = 'i';
                *b->last++ = 'l';
                break;

            case LUA_TBOOLEAN:
                if (lua_toboolean(L, i)) {
                    *b->last++ = 't';
                    *b->last++ = 'r';
                    *b->last++ = 'u';
                    *b->last++ = 'e';

                } else {
                    *b->last++ = 'f';
                    *b->last++ = 'a';
                    *b->last++ = 'l';
                    *b->last++ = 's';
                    *b->last++ = 'e';
                }

                break;

            case LUA_TTABLE:
                b->last = ngx_http_lua_copy_str_in_table(L, i, b->last);
                break;

            case LUA_TLIGHTUSERDATA:
                *b->last++ = 'n';
                *b->last++ = 'u';
                *b->last++ = 'l';
                *b->last++ = 'l';
                break;

            default:
                return luaL_error(L, "impossible to reach here");
        }
    }

    if (newline) {
        *b->last++ = '\n';
    }

#if 0
    if (b->last != b->end) {
        return luaL_error(L, "buffer error: %p != %p", b->last, b->end);
    }
#endif

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   newline ? "lua say response" : "lua print response");

    rc = ngx_http_lua_send_chain_link(r, ctx, cl);

    if (rc == NGX_ERROR || rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        return luaL_error(L, "failed to send data through the output filters");
    }

    dd("downstream write: %d, buf len: %d", (int) rc,
            (int) (b->last - b->pos));

    if (!ctx->out) {
#if nginx_version >= 1001004
        ngx_chain_update_chains(r->pool,
#else
        ngx_chain_update_chains(
#endif
                                &ctx->free_bufs, &ctx->busy_bufs, &cl, tag);

        dd("out lua buf tag: %p, buffered: %x, busy bufs: %p",
            &ngx_http_lua_module, (int) r->connection->buffered,
            ctx->busy_bufs);
    }

    return 0;
}


size_t
ngx_http_lua_calc_strlen_in_table(lua_State *L, int index, int arg_i,
    unsigned strict)
{
    double              key;
    int                 max;
    int                 i;
    int                 type;
    size_t              size;
    size_t              len;
    const char         *msg;

    if (index < 0) {
        index = lua_gettop(L) + index + 1;
    }

    dd("table index: %d", index);

    max = 0;

    lua_pushnil(L); /* stack: table key */
    while (lua_next(L, index) != 0) { /* stack: table key value */
        dd("key type: %s", luaL_typename(L, -2));

        if (lua_type(L, -2) == LUA_TNUMBER) {

            key = lua_tonumber(L, -2);

            dd("key value: %d", (int) key);

            if (floor(key) == key && key >= 1) {
                if (key > max) {
                    max = key;
                }

                lua_pop(L, 1); /* stack: table key */
                continue;
            }
        }

        /* not an array (non positive integer key) */
        lua_pop(L, 2); /* stack: table */

        msg = lua_pushfstring(L, "non-array table found");
        luaL_argerror(L, arg_i, msg);
        return 0;
    }

    size = 0;

    for (i = 1; i <= max; i++) {
        lua_rawgeti(L, index, i); /* stack: table value */
        type = lua_type(L, -1);

        switch (type) {
            case LUA_TNUMBER:
            case LUA_TSTRING:

                lua_tolstring(L, -1, &len);
                size += len;
                break;

            case LUA_TNIL:

                if (strict) {
                    goto bad_type;
                }

                size += sizeof("nil") - 1;
                break;

            case LUA_TBOOLEAN:

                if (strict) {
                    goto bad_type;
                }

                if (lua_toboolean(L, -1)) {
                    size += sizeof("true") - 1;

                } else {
                    size += sizeof("false") - 1;
                }

                break;

            case LUA_TTABLE:

                size += ngx_http_lua_calc_strlen_in_table(L, -1, arg_i, strict);
                break;

            case LUA_TLIGHTUSERDATA:

                if (strict) {
                    goto bad_type;
                }

                if (lua_touserdata(L, -1) == NULL) {
                    size += sizeof("null") - 1;
                    break;
                }

                continue;

            default:

bad_type:
                msg = lua_pushfstring(L, "bad data type %s found",
                        lua_typename(L, type));
                return luaL_argerror(L, arg_i, msg);
        }

        lua_pop(L, 1); /* stack: table */
    }

    return size;
}


u_char *
ngx_http_lua_copy_str_in_table(lua_State *L, int index, u_char *dst)
{
    double               key;
    int                  max;
    int                  i;
    int                  type;
    size_t               len;
    u_char              *p;

    if (index < 0) {
        index = lua_gettop(L) + index + 1;
    }

    max = 0;

    lua_pushnil(L); /* stack: table key */
    while (lua_next(L, index) != 0) { /* stack: table key value */
        key = lua_tonumber(L, -2);
        if (key > max) {
            max = key;
        }

        lua_pop(L, 1); /* stack: table key */
    }

    for (i = 1; i <= max; i++) {
        lua_rawgeti(L, index, i); /* stack: table value */
        type = lua_type(L, -1);
        switch (type) {
            case LUA_TNUMBER:
            case LUA_TSTRING:
                p = (u_char *) lua_tolstring(L, -1, &len);
                dst = ngx_copy(dst, p, len);
                break;

            case LUA_TNIL:
                *dst++ = 'n';
                *dst++ = 'i';
                *dst++ = 'l';
                break;

            case LUA_TBOOLEAN:
                if (lua_toboolean(L, -1)) {
                    *dst++ = 't';
                    *dst++ = 'r';
                    *dst++ = 'u';
                    *dst++ = 'e';

                } else {
                    *dst++ = 'f';
                    *dst++ = 'a';
                    *dst++ = 'l';
                    *dst++ = 's';
                    *dst++ = 'e';
                }

                break;

            case LUA_TTABLE:
                dst = ngx_http_lua_copy_str_in_table(L, -1, dst);
                break;

            case LUA_TLIGHTUSERDATA:

                *dst++ = 'n';
                *dst++ = 'u';
                *dst++ = 'l';
                *dst++ = 'l';
                break;

            default:
                luaL_error(L, "impossible to reach here");
                return NULL;
        }

        lua_pop(L, 1); /* stack: table */
    }

    return dst;
}


/**
 * Force flush out response content
 * */
static int
ngx_http_lua_ngx_flush(lua_State *L)
{
    ngx_http_request_t          *r;
    ngx_http_lua_ctx_t          *ctx;
    ngx_buf_t                   *buf;
    ngx_chain_t                 *cl;
    ngx_int_t                    rc;
    int                          n;
    unsigned                     wait = 0;
    ngx_event_t                 *wev;
    ngx_http_core_loc_conf_t    *clcf;
    ngx_http_lua_co_ctx_t       *coctx;

    n = lua_gettop(L);
    if (n > 1) {
        return luaL_error(L, "attempt to pass %d arguments, but accepted 0 "
                "or 1", n);
    }

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (n == 1 && r == r->main) {
        luaL_checktype(L, 1, LUA_TBOOLEAN);
        wait = lua_toboolean(L, 1);
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return luaL_error(L, "no request ctx found");
    }

    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                               | NGX_HTTP_LUA_CONTEXT_ACCESS
                               | NGX_HTTP_LUA_CONTEXT_CONTENT);

    coctx = ctx->cur_co_ctx;
    if (coctx == NULL) {
        return luaL_error(L, "no co ctx found");
    }

    if (r->header_only) {
        return 0;
    }

    if (ctx->eof) {
        return luaL_error(L, "already seen eof");
    }

    if (ctx->buffering) {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "lua http 1.0 buffering makes ngx.flush() a no-op");

        return 0;
    }

    if (ctx->flush_buf) {
        cl = ctx->flush_buf;

    } else {
        dd("allocating new flush buf");
        buf = ngx_calloc_buf(r->pool);
        if (buf == NULL) {
            return luaL_error(L, "memory allocation error");
        }

        buf->flush = 1;

        dd("allocating new flush chain");
        cl = ngx_alloc_chain_link(r->pool);
        if (cl == NULL) {
            return luaL_error(L, "out of memory");
        }

        cl->next = NULL;
        cl->buf = buf;

        ctx->flush_buf = cl;
    }

    rc = ngx_http_lua_send_chain_link(r, ctx, cl);

    if (rc == NGX_ERROR || rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        return luaL_error(L, "failed to send chain link: %d", (int) rc);
    }

    dd("wait:%d, rc:%d, buffered:%d", wait, (int) rc, r->connection->buffered);

    if (wait && r->connection->buffered) {
        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                "lua flush requires waiting: buffered 0x%uxd",
                (int) r->connection->buffered);

        coctx->flushing = 1;
        ctx->flushing_coros++;

        if (ctx->entered_content_phase) {
            /* mimic ngx_http_set_write_handler */
            r->write_event_handler = ngx_http_lua_content_wev_handler;

        } else {
            r->write_event_handler = ngx_http_core_run_phases;
        }

        wev = r->connection->write;

        if (wev->ready && wev->delayed) {
            return 0;
        }

        clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

        if (!wev->delayed) {
            ngx_add_timer(wev, clcf->send_timeout);
        }

        if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
            if (wev->timer_set) {
                ngx_del_timer(wev);
            }
            return luaL_error(L, "connection broken");
        }

        coctx->cleanup = ngx_http_lua_flush_cleanup;
        coctx->data = r;

        return lua_yield(L, 0);
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua flush asynchronously");

    return 0;
}


/**
 * Send last_buf, terminate output stream
 * */
static int
ngx_http_lua_ngx_eof(lua_State *L)
{
    ngx_http_request_t      *r;
    ngx_http_lua_ctx_t      *ctx;
    ngx_int_t                rc;

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "no request object found");
    }

    if (lua_gettop(L) != 0) {
        return luaL_error(L, "no argument is expected");
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return luaL_error(L, "no ctx found");
    }

    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                               | NGX_HTTP_LUA_CONTEXT_ACCESS
                               | NGX_HTTP_LUA_CONTEXT_CONTENT);

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua send eof");

    rc = ngx_http_lua_send_chain_link(r, ctx, NULL/*indicate last_buf*/);

    if (rc == NGX_ERROR || rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        return luaL_error(L, "failed to send eof buf");
    }

    return 0;
}


void
ngx_http_lua_inject_output_api(lua_State *L)
{
    lua_pushcfunction(L, ngx_http_lua_ngx_send_headers);
    lua_setfield(L, -2, "send_headers");

    lua_pushcfunction(L, ngx_http_lua_ngx_print);
    lua_setfield(L, -2, "print");

    lua_pushcfunction(L, ngx_http_lua_ngx_say);
    lua_setfield(L, -2, "say");

    lua_pushcfunction(L, ngx_http_lua_ngx_flush);
    lua_setfield(L, -2, "flush");

    lua_pushcfunction(L, ngx_http_lua_ngx_eof);
    lua_setfield(L, -2, "eof");
}


/**
 * Send out headers
 * */
static int
ngx_http_lua_ngx_send_headers(lua_State *L)
{
    ngx_http_request_t      *r;
    ngx_http_lua_ctx_t      *ctx;

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "no request found");
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return luaL_error(L, "no ctx found");
    }

    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                               | NGX_HTTP_LUA_CONTEXT_ACCESS
                               | NGX_HTTP_LUA_CONTEXT_CONTENT);

    if (!ctx->headers_sent) {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "lua send headers");

        ngx_http_lua_send_header_if_needed(r, ctx);
    }

    return 0;
}


ngx_int_t
ngx_http_lua_flush_resume_helper(ngx_http_request_t *r, ngx_http_lua_ctx_t *ctx)
{
    ngx_int_t                    rc;
    ngx_connection_t            *c;
    ngx_http_lua_main_conf_t    *lmcf;

    lmcf = ngx_http_get_module_main_conf(r, ngx_http_lua_module);

    c = r->connection;

    ctx->cur_co_ctx->cleanup = NULL;

    rc = ngx_http_lua_run_thread(lmcf->lua, r, ctx, 0);

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua run thread returned %d", rc);

    if (rc == NGX_AGAIN) {
        return ngx_http_lua_run_posted_threads(c, lmcf->lua, r, ctx);
    }

    if (rc == NGX_DONE) {
        ngx_http_finalize_request(r, NGX_DONE);
        return ngx_http_lua_run_posted_threads(c, lmcf->lua, r, ctx);
    }

    /* rc == NGX_ERROR || rc >= NGX_OK */

    if (ctx->entered_content_phase) {
        ngx_http_finalize_request(r, rc);
        return NGX_DONE;
    }

    return rc;
}


static void
ngx_http_lua_flush_cleanup(void *data)
{
    ngx_http_request_t                      *r;
    ngx_event_t                             *wev;
    ngx_http_lua_ctx_t                      *ctx;
    ngx_http_lua_co_ctx_t                   *coctx = data;

    coctx->flushing = 0;

    r = coctx->data;
    if (r == NULL) {
        return;
    }

    wev = r->connection->write;

    if (wev && wev->timer_set) {
        ngx_del_timer(wev);
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return;
    }

    ctx->flushing_coros--;
}

