/*

  pkgit - package it!

  Copyright (C) 2026 dacctal
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/

#include <sys/stat.h>
#include <unistd.h>

#include "lua.h"
#include "pkgit_lua.h"

#include "add_repo.h"
#include "build.h"
#include "fetch.h"
#include "files.h"
#include "globs.h"
#include "log.h"
#include "pkg.h"

void install_dependencies(lua_State *L) {
	while (lua_next(L, -2) != 0) {
		const char *depname = lua_tostring(L, -2);
		if (depname && lua_istable(L, -1)) {
			lua_getfield(L, -1, "url");
			str dep_url = mstr(lua_tostring(L, -1));
			lua_pop(L, 1);
			package_t pkg = pkg_create(&dep_url);
			str_free(&dep_url);
			lua_getfield(L, -1, "version");
			str_free(&pkg.version);
			const char *ver = lua_tostring(L, -1);
			pkg.version = ver ? mstr(ver) : mstr("HEAD");
			lua_pop(L, 1);
			const int top = lua_gettop(L);
			char cwd[MAX_PATH_LEN];
			if (getcwd(cwd, sizeof(cwd)) != NULL) {
				pkg_install(&pkg);
				chdir(cwd);
			}
			lua_settop(L, top);
			pkg_free(&pkg);
		}
		lua_pop(L, 1);
	}
}

bool target_install(lua_State *L, char *lua_file, str *target) {
	if (!lua_try_table(L, lua_file, target->data)) {
		lua_pop(L, 1);
		return false;
	}
	if (!lua_try_function(L, lua_file, "install")) {
		lua_pop(L, 1);
		return false;
	}
	lua_pop(L, 1);
	return true;
}

bool repo_install(package_t *pkg) {
	lua_getglobal(L, "repositories");
	if (!config_loaded || !lua_istable(L, -1)) {
		lua_isnt_type("repositories", "table");
		lua_pop(L, 1);
		return false;
	}
	if (!lua_try_table(L, "init.lua", pkg->name.data)) {
		lua_isnt_type(pkg->name.data, "table");
		lua_pop(L, 2);
		return false;
	}
	if (!lua_try_table(L, "init.lua", "targets"))
		return false;
	bool target_success = target_install(L, "init.lua", &pkg->target);
	lua_pop(L, 3);
	return target_success;
}

bool bldit_install(package_t *pkg) {
	init_bldit_state();
	if (!bldit_loaded) {
		return false;
	}
	if (!is_bldit_usable()) {
		log_error("bldit version is newer than the installed pkgit version");
		log_error("consider updating pkgit");
		if (!flags.force)
			return false;
	}
	lua_pushfstring(B, "%s", inst_dirs.prefix.data);
	lua_setglobal(B, "prefix");
	lua_getglobal(B, "targets");
	if (!lua_istable(B, -1)) {
		log_error("targets is not a table in bldit.lua!");
		return false;
	}
	bool target_success = target_install(B, "bldit.lua", &pkg->target);
	lua_pop(B, 1);
	return target_success;
}

bool config_install(package_t *pkg) {
	lua_getglobal(L, "build_systems");
	lua_pushnil(L);
	bool target_success = false;
	while (lua_next(L, -2) != 0) {
		const char *key = lua_tostring(L, -2);
		if (!lua_istable(L, -1)) {
			lua_pop(L, 1);
			continue;
		}
		str file_path = str_format("%.*s/%s", str_fmt(&pkg->src), key);
		if (access(file_path.data, F_OK) != 0) {
			lua_pop(L, 1);
			str_free(&file_path);
			continue;
		}
		str_free(&file_path);
		if (!lua_try_table(L, "init.lua", "targets")) {
			lua_pop(L, 2);
			continue;
		}
		target_success = target_install(L, "init.lua", &pkg->target);
		lua_pop(L, 2);
		if (target_success)
			break;
	}
	lua_pop(L, 1);
	return target_success;
}

void pkg_install(package_t *pkg) {
	if (is_directory(pkg->src.data)) {
		if (!flags.force) {
			log_info("%.*s is already installed.", str_fmt(&pkg->name));
			return;
		} else {
			if (flags.verbose)
				log_warn("%.*s is already installed. reinstalling...",
						 str_fmt(&pkg->name));
		}
	} else {
		mkdir(pkg->src.data, 0755);
		chdir(pkg->src.data);
	}
	char cwd[MAX_PATH_LEN];
	getcwd(cwd, MAX_PATH_LEN);
	if (str_equal_cstr(&pkg->src, cwd))
		chdir(pkg->src.data);

	if (pkg->is_local) {
		cpdir(cwd, pkg->src.data);
	} else {
		log_pkgit("fetching " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));
		if (!fetch(pkg))
			return;
		if (flags.verbose)
			log_pkgit("fetched " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));
	}

	log_pkgit("building " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));
	if (!build(pkg))
		return;
	if (flags.verbose)
		log_pkgit("built " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));

	bool install_success = false;
	if (flags.verbose)
		log_info("attempting init.lua: 'repositories.%.*s.install'",
				 str_fmt(&pkg->name));
	if (!install_success && repo_install(pkg))
		install_success = true;
	if (flags.verbose)
		log_info("attempting bldit.lua: 'repositories.%.*s.install'",
				 str_fmt(&pkg->name));
	if (!install_success && bldit_install(pkg))
		install_success = true;
	if (flags.verbose)
		log_info("attempting init.lua: 'build_systems'", str_fmt(&pkg->name));
	if (!install_success && config_install(pkg))
		install_success = true;
	if (!install_success) {
		log_error("no install function availible for package: %.*s",
				  str_fmt(&pkg->name));
		return;
	}
	log_success("installed " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));

	if (!pkg_exists(&pkg->name)) {
		log_pkgit("adding " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));
		if (pkg->url.len > 0) {
			add_repo(pkg);
			log_pkgit("added " GREEN "%.*s" COLOR_RESET, str_fmt(&pkg->name));
		}
	} else {
		log_info("repo already exists, done");
	}
}