#include <tce/syscall.h>
#include <tce/vfs.h>
#include <stdlib.h>
#include <stdio.h>

FILE out, cwd_f;
char *cwd;

void about() {
	fprint(out, "Trivial/Computing Environment v0.1.0 - yosh 2.\n");
}

void help(char *args[]) {
	if (args[1] == 0) {
		fprint(out, "Available commands: about, help, exit, ls, cd, switch.\n");
	} else if (strcmp(args[1], "about") == 0) {
		fprint(out, "Usage:\tabout\nShows some info about yosh. Very usefull.\n");
	} else if (strcmp(args[1], "help") == 0) {
		fprint(out, "Usage:\thelp\n\thelp <command>\n");
		fprint(out, "Shows some info about the command you want, or commands in general.\n");
	} else if (strcmp(args[1], "exit") == 0) {
		fprint(out, "Usage:\texit\n");
		fprint(out, "Exits the shell.\nWill probably make your system panic if you only have a shell running.\n");
	} else if (strcmp(args[1], "cd") == 0) {
		fprint(out, "Usage:\tcd <location>\nGoes to the location specified.\n");
	} else if (strcmp(args[1], "ls") == 0) {
		fprint(out, "Usage:\tls\n\tls <location>...\nShows the content of the current/specified directory.\n");
	} else if (strcmp(args[1], "switch") == 0) {
		fprint(out, "Usage:\tswitch <vt name>\nSwitchs focus to specified virtual terminal.\n");
		fprint(out, "Type `ls /.ui` to see available terminals.\n");
	} else {
		fprintf(out, "No such command: %s\n", args[1]);
	}
}

void simplify_path(char* p) {
	char *it = p;
	char *member = it;
	while (*it != 0) {
		if (*it == '/') {
			if (it == member && it != p) {
				// two consecutive slashes
				char *i = member;
				while (1) {
					i[0] = i[1];
					if (i[0] == 0) break;
					i++;
				}
			} else {
				*it = 0;
				if (strcmp(member, ".") == 0) {
					char *i = member;
					while (1) {
						i[0] = i[2];
						if (i[0] == 0) break;
						i++;
					}
				} else if (strcmp(member, "..") == 0) {
					*it = '/';
					char* start = member - 2;
					char* next = member + 3;
					while (start > p && *start != '/') {
						start--;
					}
					start++;
					it = member = start;
					while (1) {
						*start = *next;
						if (*start == 0) break;
						start++;
						next++;
					}
				} else {
					*it = '/';
					it++;
					member = it;
				}
			}
		} else {
			it++;
		}
	}
}

char* path_cat (char* a, char* b) {
	char* ret;
	if (b[0] == '/') {
		int lb = strlen(b);
		ret = (char*)malloc(lb + 2);
		memcpy(ret, b, lb);
		if (ret[lb - 1] != '/') {
			ret[lb] = '/';
			lb++;
		}
		ret[lb] = 0;
	} else {
		int la = strlen(a);
		int lb = strlen(b);

		ret = (char*)malloc(la + lb + 2);
		memcpy(ret, a, la);
		memcpy(ret + la, b, lb);
		if (ret[la + lb - 1] != '/') {
			ret[la + lb] = '/';
			lb++;
		}
		ret[la + lb] = 0;
	}
	simplify_path(ret);
	return ret;
}

void cd(char **args) {
	if (args[1] == 0) {
		fprint(out, "Usage: cd <directory>\n");
	}
	if (strcmp(args[1], ".") == 0) return;

	char* newcwd = path_cat(cwd, args[1]);

	file_info info;
	int i = stat(newcwd, &info);
	if (i == E_NOT_FOUND) {
		fprint(out, "No such file or directory.\n");
		free(newcwd);
	} else if (i < 0) {
		fprintf(out, "Error stating: %i\n", i);
		free(newcwd);
	} else if ((info.type & FT_DIR) == 0) {
		fprint(out, "Not a directory.\n");
		free(newcwd);
	} else {
		FILE nf = open(newcwd, 0);
		if (nf <= 0) {
			fprintf(out, "Error opening: %i\n", nf);
			free(newcwd);
		} else {
			free(cwd);
			cwd = newcwd;
			close(cwd_f);
			cwd_f = nf;
		}
	}
}

void ls_dir(FILE f) {
	file_info info;
	int i = 0;
	char buf[256];
	while (read(f, i, 256, buf) > 0) {
		i++;

		if (strcmp(buf, ".") == 0 || strcmp(buf, "..") == 0) continue;

		fprintf(out, "  %s", buf);

		stat_relative(f, buf, &info);
		if (info.type & FT_DIR) fprint(out, "/");
		fprint(out, "   \t");

		if (info.type & FT_FILE) fprint(out, "file ");
		if (info.type & FT_DIR) fprint(out, "dir ");
		if (info.type & FT_SYMLINK) fprint(out, "symlink ");
		if (info.type & FT_DEV) fprint(out, "dev ");
		if (info.type & FT_TERMINAL) fprint(out, "term ");

		fprint(out, "\t");
		if (info.type & FT_TERMINAL) {
			fprintf(out, "%ix%i", info.size >> 16, info.size & 0xFFFF);
		} else if ((info.type & FT_DEV) == 0) {
			fprintf(out, "%i", info.size);
		}

		fprint(out, "\n");
	}
}

void ls(char **args) {
	if (args[1] == 0) {
		ls_dir(cwd_f);
	} else {
		int i;
		for (i = 1; args[i] != 0; i++) {
			fprintf(out, "Contents of %s :\n", args[i]);
			char* d = path_cat(cwd, args[i]);
			file_info info;
			int e = stat(d, &info);
			if (e == E_NOT_FOUND) {
				fprint(out, "  No such file or directory\n");
			} else if (e < 0) {
				fprintf(out, "  Error stating: %i\n", e);
			} else {
				FILE ff = open(d, 0);
				if (ff <= 0) {
					fprintf(out, "  Error opening: %i\n", ff);
				} else {
					ls_dir(ff);
					close(ff);
				}
			}
			free(d);
		}
	}
}

void t_switch(char** args) {
	if (args[1] == 0) {
		fprint(out, "Usage: switch <vt_name>\n");
		return;
	}
	char* p = path_cat("/.ui/", args[1]);
	int i;
	if ((i = link(p, "/.dev/vgatxt", LM_OUTPUT_TO)) == 0) {
		link("/.dev/ps2kbd", p, LM_OUTPUT_TO);
	} else {
		fprintf(out, "Error %i\n", i);
	}
}

int main(char **sh_args) {
	out = open("/.ui/home", 0);
	if (out <= 0) {
		return -1;
	}

	about();

	cwd = strdup("/");
	cwd_f = open(cwd, 0);
	
	while (1) {
		fprintf(out, " %s  ", cwd);

		char *s = freadln(out);
		if (s == 0) return -1;
		int l = strlen(s);
		if (s[l-1] == '\n') {
			s[l-1] = 0; l--;

			char *c_args[16] = {0}, *cmd;
			c_args[0] = s;
			int argc = 1;
			for (cmd = s; *cmd != 0; cmd++) {
				if (*cmd == ' ') {
					*cmd = 0;
					if (cmd[1] != ' ' && cmd[1] != 0) {
						c_args[argc] = cmd + 1;
						argc++;
						if (argc == 15) break;
					}
				}
			}

			if (strcmp(c_args[0], "about") == 0) {
				about();
			} else if (strcmp(c_args[0], "help") == 0) {
				help(c_args);
			} else if (strcmp(c_args[0], "exit") == 0) {
				fprint(out, "Exiting the shell. See you later!\n");
				break;
			} else if (strcmp(c_args[0], "cd") == 0) {
				cd(c_args);
			} else if (strcmp(c_args[0], "ls") == 0) {
				ls(c_args);
			} else if (strcmp(c_args[0], "switch") == 0) {
				t_switch(c_args);
			} else {
				char *c = path_cat(cwd, c_args[0]);
				int pid = run(c, c_args + 1);
				if (pid <= 0) {
					fprintf(out, "Error %i\n", pid);
				} else {
					int ret = waitpid(pid);
					fprintf(out, "Exited with status %i\n", ret);
				}
				free(c);
			}
		} else {
			fprint(out, "[freadln fail, sorry.]\n");
		}
		free(s);
	}

	return 0;
}