#include <stdio.h>
#include <string.h>
#include "labels.h"

#define BUFSZ	80

typedef struct _LocalFile {
    const char *name;
    const char *contents;
} LocalFile;

typedef struct _Command {
    char command[BUFSZ];
    char parameter[BUFSZ];
} Command;

LocalFile files[] = {
    { "README", "Information on building your project" },
    { "info.txt", "Describe your project here" },
};
    
int ReadInput(FILE *input, char *buf, int buflen)
{
BEGIN:
    if(fgets(buf, buflen, input) != buf)
	return -1;
GOTINPUT:
    {
	int len = strlen(buf);
	/* Noted limitation:  If a line is too long, the rest of the line
	   will be interpreted as another command. */
	if(buf[len-1] != '\n') {
	    printf("Line too long: %s\n", buf);
	    return 0;
	}
	buf[len-1] = '\0';
    }
    return 0;
}

int GetFile(const char *name)
{
    int i;
    for(i=sizeof(files)/sizeof(LocalFile)-1; i>=0; --i) {
	LocalFile *f = files+i;
	if(!strcmp(f->name, name)) {
	    if(f->contents) {
		printf("%s\n", f->contents);
	    SUCCESS:
		return 0;
	    }
	}
    }
    return 1;
}

int ParseCommand(const char *buf, Command *cmd)
{
    if(sscanf(buf, "%s %s", cmd->command, cmd->parameter) != 2)
	return 1;
    return 0;
}

int ProcessCommand(const Command *cmd)
{
    if(!strcmp(cmd->command, "GET")) {
	if(GetFile(cmd->parameter)) {
	    printf("GET: Unknown file: %s\n", cmd->parameter);
	    return 1;
	}
    SUCCESS:
	return 0;
    }
    printf("Unknown command: %s\n", cmd);
    return 1;
}

void StartServer(FILE *input)
{
    char buf[BUFSZ];
    printf("Starting server...\n");
    while(ReadInput(input, buf, BUFSZ) == 0) {
	Command cmd;
	/* Check for blank line (\r in Windows) */
	if(buf[0] == '\r' || buf[0] == '\0')
	    continue;
	if(ParseCommand(buf, &cmd)) {
	    printf("Invalid command syntax: %s\n", buf);
	    continue;
	}
	if(ProcessCommand(&cmd)) {
	    printf("Command failed: %s\n", buf);
	    continue;
	}
    }
    printf("Shutting down server...\n");
}