/*
 *  Functions to manage emsMIMEtype structures
 *  for use with Eudora EMS API under MS Windows.
 *
 *  Filename: mimetype.cpp
 *
 *  Last Edited: Wednesday, April 2, 1996
 *
 *  Author: Scott Manjourides
 *
 *  Copyright 1995, 1996 QUALCOMM Inc.
 *
 *  Send comments and questions to <emsapi-info@qualcomm.com>
 */

#include <windows.h>
#include <string.h>
#include <malloc.h>

#include "ems-win.h"
#include "mimetype.h"
#include "rfc822.h"

/* ========================================================================= */

#define safefree(p) { if (p) { free(p); p = NULL; } }

/* ========================================================================= */

static void free_param_type(emsMIMEParamP paramPtr);

/* ========================================================================= */

/*
 *  Create an emsMIMEtype structure to hold MIME information. Only the
 *  type and subtype are set here, use add_mime_parameter() to add
 *  any name/value parameter pairs.
 *
 *  NOTE: All input strings are COPIED before permanent use. The user
 *        of this function is responsible for calling free_mime_type()
 *        on returned structure.
 *
 *  Args:
 *   mime_type    [IN] the main MIME type: e.g., text, application, image
 *   sub_type     [IN] the sub type: e.g., plain, octet-stream, jpeg
 *   mime_version [IN] the MIME verion number, if NULL will default to "1.0"
 *
 *  Returns: Pointer to the created emsMIMEtype structure, NULL if error.
 */
emsMIMEtypeP make_mime_type(const char *mime_type, const char *sub_type, 
							const char *mime_version)
{
	emsMIMEtypeP mimePtr = NULL;

	mimePtr = (emsMIMEtypeP) malloc(sizeof(emsMIMEtype));

	if ((mimePtr) && (mime_type) && (sub_type))
	{
		mimePtr->type = strdup(mime_type);
		mimePtr->subType = strdup(sub_type);

		if (mime_version)
			mimePtr->version = strdup(mime_version);
		else
			mimePtr->version = strdup("1.0");

		mimePtr->size = sizeof(emsMIMEtype);
		mimePtr->params = NULL;
		mimePtr->contentDisp = NULL;
		mimePtr->contentParams = NULL;

		if ((mimePtr->type) && (mimePtr->subType) && (mimePtr->version))
		{
			return mimePtr;
		}
	}

	// If we get here then something went wrong
	// Do complete cleanup and return NULL

	free_mime_type(mimePtr);

	return (NULL); // ERROR
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Create an emsMIMEtype structure to hold MIME information. Structure is
 *  initialized to values provided in RFC822 content-type header line. This
 *  includes all parameter name-value pairs.
 *   
 *  NOTE: The user of this function is responsible for calling
 *        free_mime_type() on returned structure.
 *
 *  Args:
 *   content_type [IN] The RFC822 content-type string to parse
 *
 *  Returns: Pointer to the created emsMIMEtype structure, NULL if error.
 */
emsMIMEtypeP parse_make_mime_type(const char *content_type)
{
	const char *kPrefixStr = "Content-Type:";
	const unsigned int kPrefixStrLen = strlen(kPrefixStr);

	if (strnicmp(content_type, kPrefixStr, kPrefixStrLen) != 0)
		return NULL;

	char *cp = (char *) content_type + kPrefixStrLen;
	char *mime_type = NULL, *mime_subtype = NULL;

	mime_type = rfc822_extract_token(&cp);

	if ((strlen(mime_type) > 0) && ((*cp++) == '/'))
	{
		mime_subtype = rfc822_extract_token(&cp);

		if (strlen(mime_subtype) > 0)
		{
			// We have a type/subtype, so create emsMIMEtype structure
			emsMIMEtypeP mimePtr = make_mime_type(mime_type, mime_subtype, 
													NULL);

			safefree(mime_type);
			safefree(mime_subtype);

			if (mimePtr)
			{
				char *name = NULL, *value = NULL;

				do {

					if ((*cp++) != ';') // Skip semi-colon
						break;
				
					if (!(name = rfc822_extract_token(&cp)))
						break;

					if ((*cp++) != '=') // Skip equals
						break;

					if (!(value = rfc822_extract_token(&cp)))
						break;

					if ((strlen(name) > 0) && (strlen(value) > 0))
						add_mime_parameter(mimePtr, name, value);

					safefree(name);
					safefree(value);
				} while (*cp);

				safefree(name);
				safefree(value);

				return mimePtr;
			}
		}
	}

	// If we get here then something went wrong
	// Do complete cleanup

	safefree(mime_type);
	safefree(mime_subtype);

	return (NULL); // ERROR
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Add a parameter to an existing emsMIMEtype structure. This structure
 *  should be created using make_mime_type().
 *
 *  NOTE: All input strings are COPIED before permanent use.
 *
 * Args:
 *   mimePtr [IN] Pointer to the emsMIMEtype structure to be added too
 *   name    [IN] Name of the parameter
 *   value   [IN] Value of the parameter
 *   
 *  Returns: Boolean (TRUE = success, FALSE = failure)
 */
int add_mime_parameter(emsMIMEtypeP mimePtr, const char *name, 
					   const char *value)
{
	if (!mimePtr)
		return (FALSE);
	
	emsMIMEParamP paramPtr = (emsMIMEParamP) malloc (sizeof(emsMIMEparam));

	if (paramPtr)
	{
		paramPtr->size = sizeof(emsMIMEparam);
		paramPtr->name = strdup(name);
		paramPtr->value = strdup(value);
		paramPtr->next = NULL;

		if ((paramPtr->name) && (paramPtr->value))
		{
			emsMIMEParamP *paramEnd = &(mimePtr->params);

		    while (*paramEnd)
				paramEnd = &((*paramEnd)->next);

			*paramEnd = paramPtr;

			return (TRUE);
		}
	}

	// If we get here then something went wrong
	// Do complete cleanup

	free_param_type(paramPtr);
	return (FALSE);
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Free an emsMIMEtype structure, including all strings and parameters.
 *
 *  Args:
 *   mimePtr [IN] Pointer to the emsMIMEtype structure to be freed
 *
 *  No return value.
 */
void free_mime_type(emsMIMEtypeP mimePtr)
{
	if (mimePtr)
	{
		safefree(mimePtr->version);
		safefree(mimePtr->type);
		safefree(mimePtr->subType);
		
		free_param_type(mimePtr->params);

		safefree(mimePtr->contentDisp);
		free_param_type(mimePtr->contentParams);

		safefree(mimePtr);
	}
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Convert an emsMIMEtype structure to a Content-Type header field line
 *  in the format specified by RFC 882.
 *
 *  NOTE: The user of this function is responsible for freeing the
 *        returned string.
 *
 *  Args:
 *   mimePtr [IN] Pointer to the emsMIMEtype structure
 *
 *  Returns: String containing header field; dynamically allocated.
 */
char *string_mime_type(emsMIMEtypeP mimePtr) 
{
	const char *kPrefixStr          = "Content-Type: ";
	const char *kParamSepStr        = ";\r\n  ";
	const char *kTypeSubtypeSepStr  = "/";
	const char *kAttValueSepStr     = "=";

	// Must have a valid mime structure
	if (!mimePtr)
		return NULL;

	// Both TYPE and SUBTYPE are required by RFC822
	if ((!mimePtr->type) || (!mimePtr->subType))
		return NULL;

	// Calculate the length of the header string
	unsigned int hLen = 0;

	hLen += strlen(kPrefixStr);
	hLen += rfc822_quoted_strlen(mimePtr->type);
	hLen += strlen(kTypeSubtypeSepStr);
	hLen += rfc822_quoted_strlen(mimePtr->subType);

	emsMIMEParamP paramPtr = mimePtr->params;

	while (paramPtr)
	{
		hLen += strlen(kParamSepStr);
		hLen += rfc822_quoted_strlen(paramPtr->name);
		hLen += strlen(kAttValueSepStr);
		hLen += rfc822_quoted_strlen(paramPtr->value);

		paramPtr = paramPtr->next;
	}

	// Allocate space for the header line
	char *hStr = (char *) malloc(hLen + 1);
	
	if (!hStr)
		return NULL;

	// Build the header line
	char *cp = hStr;

	cp = strchr(strcpy(cp, kPrefixStr), '\0');
	cp = rfc822_quote_strcpy(cp, mimePtr->type);
	cp = strchr(strcpy(cp, kTypeSubtypeSepStr), '\0');
	cp = rfc822_quote_strcpy(cp, mimePtr->subType);

	paramPtr = mimePtr->params;
	while (paramPtr)
	{
		cp = strchr(strcpy(cp, kParamSepStr), '\0');
		cp = rfc822_quote_strcpy(cp, paramPtr->name);
		cp = strchr(strcpy(cp, kAttValueSepStr), '\0');
		cp = rfc822_quote_strcpy(cp, paramPtr->value);

		paramPtr = paramPtr->next;
	}

	// Return the header line
	return (hStr);
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Pick out a specific parameter name-value pair from an emsMIMEtype
 *  structure. The match is case sensitive.
 *
 *  NOTE: The user of this function should NOT alter the returned string
 *        in any way -- it should be considered READ-ONLY.
 *
 *  Args:
 *   mimePtr   [IN] Pointer to the emsMIMEtype structure
 *   paramName [IN] Name of parameter to look for
 *
 *  Returns: String of the associated value or NULL if no match is found
 */
const char *get_mime_parameter(emsMIMEtypeP mimePtr, const char *paramName)
{
	if (!mimePtr)
		return NULL;

	emsMIMEParamP paramPtr = mimePtr->params;

	while (paramPtr)
	{
		if (strcmp(paramPtr->name, paramName) == 0)
			return (paramPtr->value);

		paramPtr = paramPtr->next;
	}

    return (NULL);
}				

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Remove a parameter from an existing emsMIMEtype structure. This structure
 *  should be created using make_mime_type().
 *
 *  NOTE: All input strings are COPIED before permanent use.
 *
 * Args:
 *   mimePtr [IN] Pointer to the emsMIMEtype structure to altered
 *   name    [IN] Name of the parameter to be removed
 *   
 *  Returns: Boolean (TRUE = success, FALSE = failure)
 */
int remove_mime_parameter(emsMIMEtypeP mimePtr, const char *name)
{
	if (!mimePtr)
		return (FALSE);

	emsMIMEParamP paramPtr = mimePtr->params, prevParamPtr = NULL;

	/* Find the parameter */
	while (paramPtr)
	{
		if (strcmp(paramPtr->name, name) == 0)
			break;

		prevParamPtr = paramPtr;
		paramPtr = paramPtr->next;
	}

	if (!paramPtr)
	    return (FALSE); /* Not found */

	if (prevParamPtr == NULL) /* Removing first in list */
		mimePtr->params = paramPtr->next;
	else
		prevParamPtr->next = paramPtr->next;

	paramPtr->next = NULL;
	free_param_type(paramPtr);

	return (TRUE);
}

/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

/*
 *  Check for a matching MIME type/subtype. If either type or subtype is
 *  NULL, then it won't be checked. If both are NULL, then TRUE is always
 *  returned.
 *
 *  Args:
 *   mimePtr   [IN] Pointer to the emsMIMEtype structure
 *   mime_type [IN] The major MIME type to check
 *   sub_type  [IN] The MIME subtype to check
 *  
 *  Returns: Boolean (TRUE if the MIME type matches, FALSE if not)
 */
int match_mime_type(emsMIMEtypeP mimePtr, const char *mime_type,
					const char *sub_type)
{
	if (!mimePtr)
		return (FALSE);

	return (
			((mime_type == NULL) || (stricmp(mimePtr->type, mime_type) == 0))
			&&
			((sub_type == NULL) || (stricmp(mimePtr->subType, sub_type) == 0))
		   );
}

/* ========================================================================== */
/*                              LOCAL FUNCTIONS                               */
/* ========================================================================== */

/* Private function used to free the parameter linked-list */
/* static */ void free_param_type(emsMIMEParamP paramPtr)
{
	emsMIMEParamP nextParamPtr;

	while (paramPtr)
	{
		nextParamPtr = paramPtr->next;

		safefree(paramPtr->name);
		safefree(paramPtr->value);
		safefree(paramPtr);

		paramPtr = nextParamPtr;
	}
}