// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

use std::fs;
use std::env;
use std::path::PathBuf;
use std::process::{Command, exit};

use Mode;
use Compiler;
use builder::{Step, RunConfig, ShouldRun, Builder};
use util::{copy, exe, add_lib_path};
use compile::{self, libtest_stamp, libstd_stamp, librustc_stamp};
use native;
use channel::GitInfo;
use cache::Interned;
use toolstate::ToolState;

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub struct CleanTools {
    pub compiler: Compiler,
    pub target: Interned<String>,
    pub mode: Mode,
}

impl Step for CleanTools {
    type Output = ();

    fn should_run(run: ShouldRun) -> ShouldRun {
        run.never()
    }

    fn run(self, builder: &Builder) {
        let build = builder.build;
        let compiler = self.compiler;
        let target = self.target;
        let mode = self.mode;

        // This is for the original compiler, but if we're forced to use stage 1, then
        // std/test/rustc stamps won't exist in stage 2, so we need to get those from stage 1, since
        // we copy the libs forward.
        let tools_dir = build.stage_out(compiler, Mode::Tool);
        let compiler = if builder.force_use_stage1(compiler, target) {
            builder.compiler(1, compiler.host)
        } else {
            compiler
        };

        for &cur_mode in &[Mode::Libstd, Mode::Libtest, Mode::Librustc] {
            let stamp = match cur_mode {
                Mode::Libstd => libstd_stamp(build, compiler, target),
                Mode::Libtest => libtest_stamp(build, compiler, target),
                Mode::Librustc => librustc_stamp(build, compiler, target),
                _ => panic!(),
            };

            if build.clear_if_dirty(&tools_dir, &stamp) {
                break;
            }

            // If we are a rustc tool, and std changed, we also need to clear ourselves out -- our
            // dependencies depend on std. Therefore, we iterate up until our own mode.
            if mode == cur_mode {
                break;
            }
        }
    }
}

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
struct ToolBuild {
    compiler: Compiler,
    target: Interned<String>,
    tool: &'static str,
    path: &'static str,
    mode: Mode,
    is_ext_tool: bool,
}

impl Step for ToolBuild {
    type Output = Option<PathBuf>;

    fn should_run(run: ShouldRun) -> ShouldRun {
        run.never()
    }

    /// Build a tool in `src/tools`
    ///
    /// This will build the specified tool with the specified `host` compiler in
    /// `stage` into the normal cargo output directory.
    fn run(self, builder: &Builder) -> Option<PathBuf> {
        let build = builder.build;
        let compiler = self.compiler;
        let target = self.target;
        let tool = self.tool;
        let path = self.path;
        let is_ext_tool = self.is_ext_tool;

        match self.mode {
            Mode::Libstd => builder.ensure(compile::Std { compiler, target }),
            Mode::Libtest => builder.ensure(compile::Test { compiler, target }),
            Mode::Librustc => builder.ensure(compile::Rustc { compiler, target }),
            Mode::Tool => panic!("unexpected Mode::Tool for tool build")
        }

        let _folder = build.fold_output(|| format!("stage{}-{}", compiler.stage, tool));
        println!("Building stage{} tool {} ({})", compiler.stage, tool, target);

        let mut cargo = prepare_tool_cargo(builder, compiler, target, "build", path);
        let is_expected = build.try_run(&mut cargo);
        build.save_toolstate(tool, if is_expected {
            ToolState::TestFail
        } else {
            ToolState::BuildFail
        });

        if !is_expected {
            if !is_ext_tool {
                exit(1);
            } else {
                return None;
            }
        } else {
            let cargo_out = build.cargo_out(compiler, Mode::Tool, target)
                .join(exe(tool, &compiler.host));
            let bin = build.tools_dir(compiler).join(exe(tool, &compiler.host));
            copy(&cargo_out, &bin);
            Some(bin)
        }
    }
}

pub fn prepare_tool_cargo(
    builder: &Builder,
    compiler: Compiler,
    target: Interned<String>,
    command: &'static str,
    path: &'static str,
) -> Command {
    let build = builder.build;
    let mut cargo = builder.cargo(compiler, Mode::Tool, target, command);
    let dir = build.src.join(path);
    cargo.arg("--manifest-path").arg(dir.join("Cargo.toml"));

    // We don't want to build tools dynamically as they'll be running across
    // stages and such and it's just easier if they're not dynamically linked.
    cargo.env("RUSTC_NO_PREFER_DYNAMIC", "1");

    if let Some(dir) = build.openssl_install_dir(target) {
        cargo.env("OPENSSL_STATIC", "1");
        cargo.env("OPENSSL_DIR", dir);
        cargo.env("LIBZ_SYS_STATIC", "1");
    }

    // if tools are using lzma we want to force the build script to build its
    // own copy
    cargo.env("LZMA_API_STATIC", "1");

    cargo.env("CFG_RELEASE_CHANNEL", &build.config.channel);
    cargo.env("CFG_VERSION", build.rust_version());

    let info = GitInfo::new(&build.config, &dir);
    if let Some(sha) = info.sha() {
        cargo.env("CFG_COMMIT_HASH", sha);
    }
    if let Some(sha_short) = info.sha_short() {
        cargo.env("CFG_SHORT_COMMIT_HASH", sha_short);
    }
    if let Some(date) = info.commit_date() {
        cargo.env("CFG_COMMIT_DATE", date);
    }
    cargo
}

macro_rules! tool {
    ($($name:ident, $path:expr, $tool_name:expr, $mode:expr;)+) => {
        #[derive(Copy, Clone)]
        pub enum Tool {
            $(
                $name,
            )+
        }

        impl<'a> Builder<'a> {
            pub fn tool_exe(&self, tool: Tool) -> PathBuf {
                let stage = self.tool_default_stage(tool);
                match tool {
                    $(Tool::$name =>
                        self.ensure($name {
                            compiler: self.compiler(stage, self.build.build),
                            target: self.build.build,
                        }),
                    )+
                }
            }

            pub fn tool_default_stage(&self, tool: Tool) -> u32 {
                // Compile the error-index in the same stage as rustdoc to avoid
                // recompiling rustdoc twice if we can. Otherwise compile
                // everything else in stage0 as there's no need to rebootstrap
                // everything.
                match tool {
                    Tool::ErrorIndex if self.top_stage >= 2 => self.top_stage,
                    _ => 0,
                }
            }
        }

        $(
            #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
        pub struct $name {
            pub compiler: Compiler,
            pub target: Interned<String>,
        }

        impl Step for $name {
            type Output = PathBuf;

            fn should_run(run: ShouldRun) -> ShouldRun {
                run.path($path)
            }

            fn make_run(run: RunConfig) {
                run.builder.ensure($name {
                    compiler: run.builder.compiler(run.builder.top_stage, run.builder.build.build),
                    target: run.target,
                });
            }

            fn run(self, builder: &Builder) -> PathBuf {
                builder.ensure(ToolBuild {
                    compiler: self.compiler,
                    target: self.target,
                    tool: $tool_name,
                    mode: $mode,
                    path: $path,
                    is_ext_tool: false,
                }).expect("expected to build -- essential tool")
            }
        }
        )+
    }
}

tool!(
    Rustbook, "src/tools/rustbook", "rustbook", Mode::Librustc;
    ErrorIndex, "src/tools/error_index_generator", "error_index_generator", Mode::Librustc;
    UnstableBookGen, "src/tools/unstable-book-gen", "unstable-book-gen", Mode::Libstd;
    Tidy, "src/tools/tidy", "tidy", Mode::Libstd;
    Linkchecker, "src/tools/linkchecker", "linkchecker", Mode::Libstd;
    CargoTest, "src/tools/cargotest", "cargotest", Mode::Libstd;
    Compiletest, "src/tools/compiletest", "compiletest", Mode::Libtest;
    BuildManifest, "src/tools/build-manifest", "build-manifest", Mode::Libstd;
    RemoteTestClient, "src/tools/remote-test-client", "remote-test-client", Mode::Libstd;
    RustInstaller, "src/tools/rust-installer", "fabricate", Mode::Libstd;
    RustdocTheme, "src/tools/rustdoc-themes", "rustdoc-themes", Mode::Libstd;
);

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub struct RemoteTestServer {
    pub compiler: Compiler,
    pub target: Interned<String>,
}

impl Step for RemoteTestServer {
    type Output = PathBuf;

    fn should_run(run: ShouldRun) -> ShouldRun {
        run.path("src/tools/remote-test-server")
    }

    fn make_run(run: RunConfig) {
        run.builder.ensure(RemoteTestServer {
            compiler: run.builder.compiler(run.builder.top_stage, run.builder.build.build),
            target: run.target,
        });
    }

    fn run(self, builder: &Builder) -> PathBuf {
        builder.ensure(ToolBuild {
            compiler: self.compiler,
            target: self.target,
            tool: "remote-test-server",
            mode: Mode::Libstd,
            path: "src/tools/remote-test-server",
            is_ext_tool: false,
        }).expect("expected to build -- essential tool")
    }
}

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub struct Rustdoc {
    pub host: Interned<String>,
}

impl Step for Rustdoc {
    type Output = PathBuf;
    const DEFAULT: bool = true;
    const ONLY_HOSTS: bool = true;

    fn should_run(run: ShouldRun) -> ShouldRun {
        run.path("src/tools/rustdoc")
    }

    fn make_run(run: RunConfig) {
        run.builder.ensure(Rustdoc {
            host: run.host,
        });
    }

    fn run(self, builder: &Builder) -> PathBuf {
        let build = builder.build;
        let target_compiler = builder.compiler(builder.top_stage, self.host);
        let target = target_compiler.host;
        let build_compiler = if target_compiler.stage == 0 {
            builder.compiler(0, builder.build.build)
        } else if target_compiler.stage >= 2 {
            // Past stage 2, we consider the compiler to be ABI-compatible and hence capable of
            // building rustdoc itself.
            builder.compiler(target_compiler.stage, builder.build.build)
        } else {
            // Similar to `compile::Assemble`, build with the previous stage's compiler. Otherwise
            // we'd have stageN/bin/rustc and stageN/bin/rustdoc be effectively different stage
            // compilers, which isn't what we want.
            builder.compiler(target_compiler.stage - 1, builder.build.build)
        };

        builder.ensure(compile::Rustc { compiler: build_compiler, target });

        let _folder = build.fold_output(|| format!("stage{}-rustdoc", target_compiler.stage));
        println!("Building rustdoc for stage{} ({})", target_compiler.stage, target_compiler.host);

        let mut cargo = prepare_tool_cargo(builder,
                                           build_compiler,
                                           target,
                                           "build",
                                           "src/tools/rustdoc");

        // Most tools don't get debuginfo, but rustdoc should.
        cargo.env("RUSTC_DEBUGINFO", builder.config.rust_debuginfo.to_string())
             .env("RUSTC_DEBUGINFO_LINES", builder.config.rust_debuginfo_lines.to_string());

        build.run(&mut cargo);
        // Cargo adds a number of paths to the dylib search path on windows, which results in
        // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
        // rustdoc a different name.
        let tool_rustdoc = build.cargo_out(build_compiler, Mode::Tool, target)
            .join(exe("rustdoc-tool-binary", &target_compiler.host));

        // don't create a stage0-sysroot/bin directory.
        if target_compiler.stage > 0 {
            let sysroot = builder.sysroot(target_compiler);
            let bindir = sysroot.join("bin");
            t!(fs::create_dir_all(&bindir));
            let bin_rustdoc = bindir.join(exe("rustdoc", &*target_compiler.host));
            let _ = fs::remove_file(&bin_rustdoc);
            copy(&tool_rustdoc, &bin_rustdoc);
            bin_rustdoc
        } else {
            tool_rustdoc
        }
    }
}

#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
pub struct Cargo {
    pub compiler: Compiler,
    pub target: Interned<String>,
}

impl Step for Cargo {
    type Output = PathBuf;
    const DEFAULT: bool = true;
    const ONLY_HOSTS: bool = true;

    fn should_run(run: ShouldRun) -> ShouldRun {
        let builder = run.builder;
        run.path("src/tools/cargo").default_condition(builder.build.config.extended)
    }

    fn make_run(run: RunConfig) {
        run.builder.ensure(Cargo {
            compiler: run.builder.compiler(run.builder.top_stage, run.builder.build.build),
            target: run.target,
        });
    }

    fn run(self, builder: &Builder) -> PathBuf {
        builder.ensure(native::Openssl {
            target: self.target,
        });
        // Cargo depends on procedural macros, which requires a full host
        // compiler to be available, so we need to depend on that.
        builder.ensure(compile::Rustc {
            compiler: self.compiler,
            target: builder.build.build,
        });
        builder.ensure(ToolBuild {
            compiler: self.compiler,
            target: self.target,
            tool: "cargo",
            mode: Mode::Librustc,
            path: "src/tools/cargo",
            is_ext_tool: false,
        }).expect("expected to build -- essential tool")
    }
}

macro_rules! tool_extended {
    (($sel:ident, $builder:ident),
       $($name:ident,
       $toolstate:ident,
       $path:expr,
       $tool_name:expr,
       $extra_deps:block;)+) => {
        $(
            #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq)]
        pub struct $name {
            pub compiler: Compiler,
            pub target: Interned<String>,
        }

        impl Step for $name {
            type Output = Option<PathBuf>;
            const DEFAULT: bool = true;
            const ONLY_HOSTS: bool = true;

            fn should_run(run: ShouldRun) -> ShouldRun {
                let builder = run.builder;
                run.path($path).default_condition(builder.build.config.extended)
            }

            fn make_run(run: RunConfig) {
                run.builder.ensure($name {
                    compiler: run.builder.compiler(run.builder.top_stage, run.builder.build.build),
                    target: run.target,
                });
            }

            fn run($sel, $builder: &Builder) -> Option<PathBuf> {
                $extra_deps
                $builder.ensure(ToolBuild {
                    compiler: $sel.compiler,
                    target: $sel.target,
                    tool: $tool_name,
                    mode: Mode::Librustc,
                    path: $path,
                    is_ext_tool: true,
                })
            }
        }
        )+
    }
}

tool_extended!((self, builder),
    Cargofmt, rustfmt, "src/tools/rustfmt", "cargo-fmt", {};
    Clippy, clippy, "src/tools/clippy", "clippy-driver", {
        // Clippy depends on procedural macros (serde), which requires a full host
        // compiler to be available, so we need to depend on that.
        builder.ensure(compile::Rustc {
            compiler: self.compiler,
            target: builder.build.build,
        });
    };
    Miri, miri, "src/tools/miri", "miri", {};
    Rls, rls, "src/tools/rls", "rls", {
        builder.ensure(native::Openssl {
            target: self.target,
        });
        // RLS depends on procedural macros, which requires a full host
        // compiler to be available, so we need to depend on that.
        builder.ensure(compile::Rustc {
            compiler: self.compiler,
            target: builder.build.build,
        });
    };
    Rustfmt, rustfmt, "src/tools/rustfmt", "rustfmt", {};
);

impl<'a> Builder<'a> {
    /// Get a `Command` which is ready to run `tool` in `stage` built for
    /// `host`.
    pub fn tool_cmd(&self, tool: Tool) -> Command {
        let mut cmd = Command::new(self.tool_exe(tool));
        let compiler = self.compiler(self.tool_default_stage(tool), self.build.build);
        self.prepare_tool_cmd(compiler, &mut cmd);
        cmd
    }

    /// Prepares the `cmd` provided to be able to run the `compiler` provided.
    ///
    /// Notably this munges the dynamic library lookup path to point to the
    /// right location to run `compiler`.
    fn prepare_tool_cmd(&self, compiler: Compiler, cmd: &mut Command) {
        let host = &compiler.host;
        let mut paths: Vec<PathBuf> = vec![
            PathBuf::from(&self.sysroot_libdir(compiler, compiler.host)),
            self.cargo_out(compiler, Mode::Tool, *host).join("deps"),
        ];

        // On MSVC a tool may invoke a C compiler (e.g. compiletest in run-make
        // mode) and that C compiler may need some extra PATH modification. Do
        // so here.
        if compiler.host.contains("msvc") {
            let curpaths = env::var_os("PATH").unwrap_or_default();
            let curpaths = env::split_paths(&curpaths).collect::<Vec<_>>();
            for &(ref k, ref v) in self.cc[&compiler.host].env() {
                if k != "PATH" {
                    continue
                }
                for path in env::split_paths(v) {
                    if !curpaths.contains(&path) {
                        paths.push(path);
                    }
                }
            }
        }
        add_lib_path(paths, cmd);
    }
}