#ifndef TASKS_H
#define TASKS_H

#include "stdint.h"

#define TASK_STACK_SIZE 4096

#if defined( __TINYC__ )
#pragma pack(1)
#endif

typedef struct {
	// pushed by us
	uint32_t eax;
	uint32_t ebx;
	uint32_t ecx;
	uint32_t edx;
	uint32_t esi;
	uint32_t edi;
	uint32_t ebp;	
	
	// really needed?
	//~ uint32_t gs;
	//~ uint32_t fs;	
	//~ uint32_t es;	
	//~ uint32_t ds;
	
	// ?
	uint32_t error;
	
	// pushed by the CPU
	uint32_t eip;
	uint32_t cs;	
	uint32_t eflags;	
	uint32_t esp;
	uint32_t ss;
} __attribute__( ( packed ) ) cpu_state_t;

#if defined( __TINYC__ )
#pragma pack()
#endif

typedef struct {
	uint8_t stack[TASK_STACK_SIZE];
        cpu_state_t *cpu_state;
	int nof_switches;
} task_t;

typedef void (*task_func_t)( void );

void task_init( task_t *task, uint16_t gdt_code_segment_selector, task_func_t entrypoint );

#define MAX_NOF_TASKS 256

typedef struct {
	int nof_tasks;
	int current_task;
	task_t *task[MAX_NOF_TASKS];
} task_manager_t;

void task_manager_init( task_manager_t *manager );
void task_manager_add_task( task_manager_t *manager, task_t *task );
cpu_state_t *task_manager_schedule_task( task_manager_t *manager, cpu_state_t *cpu_state );

#endif // TASKS_H