#ifndef LEVDIST_H
#define LEVDIST_H


/** @file levdist.h

This file contains the structures and functions that control the entire
`levdist` command. It can be thought as the global controller object
in object-oriented programming.

It may be created in the main function, for example:

```
int main(int argc, char* argv[])
{
	levdist_t levdist;
	levdist_init(&levdist);
	return levdist_run(&levdist, argc, argv);
}
```
*/

#include "arguments.h"
#include "dir.h"

/**
	@brief For each file we know its name, size, and contents
	@todo: Move file_record_t to its own file and include it in dir.h
**/
typedef struct
{
	/// Path to the filename, relative to the levdist command call
	char* filename;
	/// Size in bytes of the file
	off_t size;
	/// Pointer to its contents in ASCII or Unicode
	void* contents;
} file_record_t;

/**
	@brief A comparison between two files that stores their Levenshtein distance
*/
typedef struct
{
	/// The first file to compare
	file_record_t* file1;
	/// The second file to compare
	file_record_t* file2;
	/// Levenshtein distance between the two files
	size_t distance;
} comparison_t;


/**
	@brief Stores the atributes shared for the controller functions in this file.
*/
typedef struct levdist
{
	/// What user asked by the command-line arguments.
	arguments_t arguments;
	/// Queue of files to be compared using Levenshtein distance.
	queue_t* files;
	/// Array of pairs of files to be compared
	comparison_t* comparisons;
} levdist_t;


/**
	@brief Initializes a record with default information required by the controller.

	@param this Pointer to the @a levdist_t structure to be initialized.
*/
void levdist_init(levdist_t* this);


/**
	@brief Start the execution of the command

	@param this Pointer to the @a levdist_t structure with the shared attibutes.
	@param argc Argument count provided from the `main()` function.
	@param argv Argument vector provided from the `main()` function.
	@return The exit status, where 0 stands for success, otherwise for an error.
*/
int levdist_run(levdist_t* this, int argc, char* argv[]);


/**
	@brief Finds all files in the directories given by arguments, and load them to
	the @a this->files queue.

	@param this Pointer to the @a levdist_t structure with the shared attibutes.
	@param argc Argument count provided from the `main()` function.
	@param argv Argument vector provided from the `main()` function.
	@return The exit status, where 0 stands for success, otherwise for an error.
*/
int levdist_process_dirs(levdist_t* this, int argc, char* argv[]);


/**
	@brief Traverses all the directories provided by user in command-line arguments, and
	load all files to the @a this->files queue.

	@param this Pointer to the @a levdist_t structure with the shared attibutes.
	@param argc Argument count provided from the `main()` function.
	@param argv Argument vector provided from the `main()` function.
	@return The exit status, where 0 stands for success, otherwise for an error.
*/
int levdist_list_files_in_args(levdist_t* this, int argc, char* argv[]);

/**
	@brief Returns true if the given filename is already in the files queue.

	@param this Pointer to the @a levdist_t structure with the shared attibutes.
	@param filename The filename to be searched.
	@return true if the given filename is already in the files queue.
*/
bool levdist_is_in_queue(levdist_t* this, const char* filename);

/**
	@brief Loads the contents of the given file and add them to the files queue.

	@param this Pointer to the @a levdist_t structure with the shared attibutes.
	@param filename The relative path and name of the file to be loaded.
	@param load_contents If true, file's contents will be loaded to heap memory.
	@return The exit status, where 0 stands for success, otherwise for an error.
*/
int levdist_load_file(levdist_t* this, const char* filename, bool load_contents);

/**
	@brief Releases the heap memory used
	@param this Pointer to the @a levdist_t structure with the shared attibutes.
*/
void levdist_destroy(levdist_t* this);

#endif // LEVDIST_H