/*
base_cmd.c - command & cvar hashmap. Insipred by Doom III
Copyright (C) 2016 a1batross

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
*/

#include "common.h"
#include "base_cmd.h"
#include "cdll_int.h"

#define HASH_SIZE 128 // 128 * 4 * 4 == 2048 bytes

typedef struct base_command_hashmap_s base_command_hashmap_t;

struct base_command_hashmap_s
{
	base_command_t         *basecmd; // base command: cvar, alias or command
	base_command_hashmap_t *next;
	base_command_type_e     type;    // type for faster searching
	char                    name[1]; // key for searching
};

static base_command_hashmap_t *hashed_cmds[HASH_SIZE];

#define BaseCmd_HashKey( x ) COM_HashKey( name, HASH_SIZE )

/*
============
BaseCmd_FindInBucket

Find base command in bucket
============
*/
static base_command_hashmap_t *BaseCmd_FindInBucket( base_command_hashmap_t *bucket, base_command_type_e type, const char *name )
{
	base_command_hashmap_t *i = bucket;
	for( ; i && ( i->type != type || Q_stricmp( name, i->name ) ); // filter out
		 i = i->next );

	return i;
}

/*
============
BaseCmd_GetBucket

Get bucket which contain basecmd by given name
============
*/
static base_command_hashmap_t *BaseCmd_GetBucket( const char *name )
{
	return hashed_cmds[ BaseCmd_HashKey( name ) ];
}

/*
============
BaseCmd_Find

Find base command in hashmap
============
*/
base_command_t *BaseCmd_Find( base_command_type_e type, const char *name )
{
	base_command_hashmap_t *base = BaseCmd_GetBucket( name );
	base_command_hashmap_t *found = BaseCmd_FindInBucket( base, type, name );

	if( found )
		return found->basecmd;
	return NULL;
}

/*
============
BaseCmd_Find

Find every type of base command and write into arguments
============
*/
void BaseCmd_FindAll( const char *name, base_command_t **cmd, base_command_t **alias, base_command_t **cvar )
{
	base_command_hashmap_t *base = BaseCmd_GetBucket( name );
	base_command_hashmap_t *i = base;

	ASSERT( cmd && alias && cvar );

	*cmd = *alias = *cvar = NULL;

	for( ; i; i = i->next )
	{
		if( !Q_stricmp( i->name, name ) )
		{
			switch( i->type )
			{
			case HM_CMD:
				*cmd = i->basecmd;
				break;
			case HM_CMDALIAS:
				*alias = i->basecmd;
				break;
			case HM_CVAR:
				*cvar = i->basecmd;
				break;
			default: break;
			}
		}
	}
}

/*
============
BaseCmd_Insert

Add new typed base command to hashmap
============
*/
void BaseCmd_Insert( base_command_type_e type, base_command_t *basecmd, const char *name )
{
	base_command_hashmap_t *elem, *cur, *find;
	uint hash = BaseCmd_HashKey( name );
	size_t len = Q_strlen( name );

	elem = Z_Malloc( sizeof( base_command_hashmap_t ) + len );
	elem->basecmd = basecmd;
	elem->type = type;
	Q_strncpy( elem->name, name, len + 1 );

	// link the variable in alphanumerical order
	for( cur = NULL, find = hashed_cmds[hash];
		  find && Q_strcmp( find->name, elem->name ) < 0;
		  cur = find, find = find->next );

	if( cur ) cur->next = elem;
	else hashed_cmds[hash] = elem;

	elem->next = find;
}

/*
============
BaseCmd_Remove

Remove base command from hashmap
============
*/
void BaseCmd_Remove( base_command_type_e type, const char *name )
{
	uint hash = BaseCmd_HashKey( name );
	base_command_hashmap_t *i, *prev;

	for( prev = NULL, i = hashed_cmds[hash]; i &&
		 ( Q_strcmp( i->name, name ) || i->type != type); // filter out
		 prev = i, i = i->next );

	if( !i )
	{
		Con_Reportf( S_ERROR  "Couldn't find %s in buckets\n", name );
		return;
	}

	if( prev )
		prev->next = i->next;
	else
		hashed_cmds[hash] = i->next;

	Z_Free( i );
}

/*
============
BaseCmd_Init

initialize base command hashmap system
============
*/
void BaseCmd_Init( void )
{
	memset( hashed_cmds, 0, sizeof( hashed_cmds ) );
}

/*
============
BaseCmd_Stats_f

============
*/
void BaseCmd_Stats_f( void )
{
	int i, minsize = 99999, maxsize = -1, empty = 0;

	for( i = 0; i < HASH_SIZE; i++ )
	{
		base_command_hashmap_t *hm;
		int len = 0;

		// count bucket length
		for( hm = hashed_cmds[i]; hm; hm = hm->next, len++ );

		if( len == 0 )
		{
			empty++;
			continue;
		}

		if( len < minsize )
			minsize = len;

		if( len > maxsize )
			maxsize = len;

	}

	Con_Printf( "min length: %d, max length: %d, empty: %d\n", minsize, maxsize, empty );
}

typedef struct
{
	qboolean valid;
	int lookups;
} basecmd_test_stats_t;

static void BaseCmd_CheckCvars( const char *key, const char *value, const void *unused, void *ptr )
{
	basecmd_test_stats_t *stats = ptr;

	stats->lookups++;
	if( !BaseCmd_Find( HM_CVAR, key ))
	{
		Con_Printf( "Cvar %s is missing in basecmd\n", key );
		stats->valid = false;
	}
}

/*
============
BaseCmd_Stats_f

testing order matches cbuf execute
============
*/
void BaseCmd_Test_f( void )
{
	basecmd_test_stats_t stats;
	double start, end, dt;
	int i;

	stats.valid = true;
	stats.lookups = 0;

	start = Sys_DoubleTime() * 1000;

	for( i = 0; i < 1000; i++ )
	{
		cmdalias_t *a;
		void *cmd;

		// Cmd_LookupCmds don't allows to check alias, so just iterate
		for( a = Cmd_AliasGetList(); a; a = a->next, stats.lookups++ )
		{
			if( !BaseCmd_Find( HM_CMDALIAS, a->name ))
			{
				Con_Printf( "Alias %s is missing in basecmd\n", a->name );
				stats.valid = false;
			}
		}

		for( cmd = Cmd_GetFirstFunctionHandle(); cmd;
			 cmd = Cmd_GetNextFunctionHandle( cmd ), stats.lookups++ )
		{
			if( !BaseCmd_Find( HM_CMD, Cmd_GetName( cmd )))
			{
				Con_Printf( "Command %s is missing in basecmd\n", Cmd_GetName( cmd ));
				stats.valid = false;
			}
		}

		Cvar_LookupVars( 0, NULL, &stats.valid, (setpair_t)BaseCmd_CheckCvars );
	}

	end = Sys_DoubleTime() * 1000;

	dt = end - start;

	if( !stats.valid )
		Con_Printf( "BaseCmd is valid\n" );

	Con_Printf( "Test took %.3f ms, %d lookups, %.3f us/lookup\n", dt, stats.lookups, dt / stats.lookups * 1000 );

	BaseCmd_Stats_f();
}