// Copyright (c) 2016, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

import {readdirSync} from 'node:fs';
import path from 'node:path';

import {SemVer} from 'semver';
import _ from 'underscore';

import {ExecutionOptionsWithEnv} from '../../types/compilation/compilation.interfaces.js';
import {CompilerOverrideType, ConfiguredOverrides} from '../../types/compilation/compiler-overrides.interfaces.js';
import {LLVMIrBackendOptions} from '../../types/compilation/ir.interfaces.js';
import type {PreliminaryCompilerInfo} from '../../types/compiler.interfaces.js';
import type {BasicExecutionResult, UnprocessedExecResult} from '../../types/execution/execution.interfaces.js';
import type {ParseFiltersAndOutputOptions} from '../../types/features/filters.interfaces.js';
import {SelectedLibraryVersion} from '../../types/libraries/libraries.interfaces.js';
import {unwrap} from '../assert.js';
import {BaseCompiler} from '../base-compiler.js';
import type {BuildEnvDownloadInfo} from '../buildenvsetup/buildenv.interfaces.js';
import {CompilationEnvironment} from '../compilation-env.js';
import {changeExtension, parseRustOutput} from '../utils.js';
import {RustParser} from './argument-parsers.js';

export class RustCompiler extends BaseCompiler {
    amd64linker: string;
    aarch64linker: string;

    static get key() {
        return 'rust';
    }

    constructor(info: PreliminaryCompilerInfo, env: CompilationEnvironment) {
        super(info, env);
        this.compiler.supportsIntel = true;
        this.compiler.supportsIrView = true;
        this.compiler.supportsRustMirView = true;
        this.compiler.supportsVerboseDemangling = true;

        const isNightly = this.isNightly();
        // Macro expansion (-Zunpretty=expanded) and HIR (-Zunpretty=hir-tree)
        // are only available for Nightly
        this.compiler.supportsRustMacroExpView = isNightly;
        this.compiler.supportsRustHirView = isNightly;
        if (this.compiler.name === 'rustc nightly') {
            this.compiler.supportsOptOutput = true;
            // not setting compiler.optArg, overriding prepareOptRemarksArgs instead (2 args needed)
        }

        this.compiler.irArg = ['--emit', 'llvm-ir'];
        this.compiler.minIrArgs = ['--emit=llvm-ir'];
        this.compiler.optPipeline = {
            arg: ['-C', 'llvm-args=-print-after-all -print-before-all', '-C', 'extra-filename=llvm-opt-pipeline'],
            moduleScopeArg: ['-C', 'llvm-args=-print-module-scope'],
            noDiscardValueNamesArg: isNightly ? ['-Z', 'fewer-names=no'] : [],
        };
        this.amd64linker = this.compilerProps<string>('linker');
        this.aarch64linker = this.compilerProps<string>('aarch64linker');
    }

    override async generateIR(
        inputFilename: string,
        options: string[],
        irOptions: LLVMIrBackendOptions,
        produceCfg: boolean,
        filters: ParseFiltersAndOutputOptions,
    ) {
        // Filter out the options pairs `--emit mir=*` and `emit asm`, and specify explicit `.ll` extension
        const newOptions = options
            .filter(option => !option.startsWith('--color='))
            .filter(
                (opt, idx, allOpts) =>
                    !(opt === '--emit' && allOpts[idx + 1].startsWith('mir=')) && !opt.startsWith('mir='),
            )
            .filter((opt, idx, allOpts) => !(opt === '--emit' && allOpts[idx + 1] === 'asm') && opt !== 'asm')
            .map((opt, idx, allOpts) =>
                opt.endsWith('.s') && idx > 0 && allOpts[idx - 1] === '-o'
                    ? this.getIrOutputFilename(inputFilename, filters)
                    : opt,
            );
        // Rust intermediate files that get copied to the output get a name of the form "base-HASH-*" -- so
        // if there are any other compiles running on the same code with `--emit-llvm` then those will clash
        // with the output and lead to corruptions/missing files. We use a uniquifier here for each potentially
        // concurrent pass. With thanks to @bjorn3.
        // See https://github.com/compiler-explorer/compiler-explorer/issues/7012 for example
        newOptions.push('--codegen', 'extra-filename=llvm-ir-gen');
        return await super.generateIR(inputFilename, newOptions, irOptions, produceCfg, filters);
    }

    private isNightly() {
        return (
            this.compiler.name === 'nightly' ||
            this.compiler.semver === 'nightly' ||
            this.compiler.semver === 'beta' ||
            this.compiler.semver.includes('master') ||
            this.compiler.semver.includes('trunk')
        );
    }

    override async populatePossibleOverrides() {
        const possibleEditions = await this.argParser.getPossibleEditions();
        if (possibleEditions.length > 0) {
            let defaultEdition: undefined | string;
            if (!this.compiler.semver || this.isNightly()) {
                defaultEdition = '2024';
            } else {
                const compilerVersion = new SemVer(this.compiler.semver);
                if (compilerVersion.compare('1.85.0') >= 0) {
                    defaultEdition = '2024';
                } else if (compilerVersion.compare('1.56.0') >= 0) {
                    defaultEdition = '2021';
                }
            }

            this.compiler.possibleOverrides?.push({
                type: 'options',
                name: CompilerOverrideType.edition,
                display_title: 'Edition',
                description:
                    'The default edition for Rust compilers is usually 2015. ' +
                    'Some editions might not be available for older compilers.',
                flags: ['--edition', '<value>'],
                values: possibleEditions.map(ed => {
                    return {name: ed, value: ed};
                }),
                default: defaultEdition,
            });
        }

        await super.populatePossibleOverrides();
    }

    override getSharedLibraryPathsAsArguments(libraries: SelectedLibraryVersion[], libDownloadPath?: string) {
        return [];
    }

    override getSharedLibraryLinks(libraries: SelectedLibraryVersion[]): string[] {
        return [];
    }

    override getIncludeArguments(libraries: SelectedLibraryVersion[]) {
        const includeFlag = '--extern';
        return libraries.flatMap(selectedLib => {
            const foundVersion = this.findLibVersion(selectedLib);
            if (!foundVersion || !foundVersion.name) return [];
            const lowercaseLibName = foundVersion.name.replaceAll('-', '_');
            return foundVersion.path.flatMap(rlib => {
                return [
                    includeFlag,
                    `${lowercaseLibName}=${foundVersion.name}/build/debug/${rlib}`,
                    '-L',
                    `dependency=${foundVersion.name}/build/debug/deps`,
                ];
            });
        });
    }

    override orderArguments(
        options: string[],
        inputFilename: string,
        libIncludes: string[],
        libOptions: string[],
        libPaths: string[],
        libLinks: string[],
        userOptions: string[],
        staticLibLinks: string[],
    ) {
        return options.concat(userOptions, libIncludes, libOptions, libPaths, libLinks, staticLibLinks, [
            this.filename(inputFilename),
        ]);
    }

    override async setupBuildEnvironment(key: any, dirPath: string): Promise<BuildEnvDownloadInfo[]> {
        if (this.buildenvsetup) {
            const libraryDetails = await this.getRequiredLibraryVersions(key.libraries);
            return this.buildenvsetup.setup(key, dirPath, libraryDetails);
        }
        return [];
    }

    override fixIncompatibleOptions(
        options: string[],
        userOptions: string[],
        overrides: ConfiguredOverrides,
    ): [string[], ConfiguredOverrides] {
        if (userOptions.filter(option => option.startsWith('--color=')).length > 0) {
            options = options.filter(option => !option.startsWith('--color='));
        }

        const editionOverrideIdx = overrides.findIndex(ovr => ovr.name === 'edition');
        if (editionOverrideIdx !== -1) {
            if (
                options.some(opt => opt.startsWith('--edition')) ||
                userOptions.some(opt => opt.startsWith('--edition'))
            )
                // Prefer the options edition over the overrides
                overrides.splice(editionOverrideIdx, 1);
        }

        return [options, overrides];
    }

    override changeOptionsBasedOnOverrides(options: string[], overrides: ConfiguredOverrides): string[] {
        const newOptions = super.changeOptionsBasedOnOverrides(options, overrides);

        if (this.aarch64linker) {
            const useAarch64Linker = !!overrides.find(
                override => override.name === CompilerOverrideType.arch && override.value.includes('aarch64'),
            );

            if (useAarch64Linker) {
                for (let idx = 0; idx < newOptions.length; idx++) {
                    if (newOptions[idx].indexOf('-Clinker=') === 0) {
                        newOptions[idx] = `-Clinker=${this.aarch64linker}`;
                    }
                }
            }
        }

        return newOptions;
    }

    override optionsForBackend(backendOptions: Record<string, any>, outputFilename: string) {
        // The super class handles the GCC dump files that may be needed by
        // rustc-cg-gcc subclass.
        const opts = super.optionsForBackend(backendOptions, outputFilename);

        if (backendOptions.produceRustMir && this.compiler.supportsRustMirView) {
            const of = this.getRustMirOutputFilename(outputFilename);
            opts.push('--emit', `mir=${of}`);
        }
        return opts;
    }

    override getOptFilePath(dirPath: string, outputFilebase: string): string {
        // Find a file in dirPath that ends with codegen.opt.yaml, and return it
        // A bit of a hack, but it works for now
        const files = readdirSync(dirPath);
        for (const file of files) {
            if (file.endsWith('codegen.opt.yaml')) {
                return path.join(dirPath, file);
            }
        }
        return '';
    }

    override prepareOptRemarksArgs(options: string[], outputFilename: string): string[] {
        const outputDir = path.dirname(outputFilename);
        return options.concat(['-Cremark=all', `-Zremark-dir=${outputDir}`]);
    }

    override optionsForFilter(filters: ParseFiltersAndOutputOptions, outputFilename: string, userOptions?: string[]) {
        let options = ['-C', 'debuginfo=2', '-o', this.filename(outputFilename)];

        const userRequestedEmit = _.any(unwrap(userOptions), opt => opt.includes('--emit'));
        const userRequestedCrateType = _.any(unwrap(userOptions), opt => opt.includes('--crate-type'));
        const setCrateType = (options, type) =>
            userRequestedCrateType ? options : options.concat(['--crate-type', type]);
        if (filters.binary) {
            options = setCrateType(options, 'bin');
            if (this.amd64linker) {
                options = options.concat(`-Clinker=${this.amd64linker}`);
            }
        } else if (filters.binaryObject) {
            options = setCrateType(options, 'lib');
        } else {
            if (!userRequestedEmit) {
                options = options.concat('--emit', 'asm');
            }
            if (filters.intel) options = options.concat('-Cllvm-args=--x86-asm-syntax=intel');
            options = setCrateType(options, 'rlib');
        }
        return options;
    }

    override optionsForDemangler(filters?: ParseFiltersAndOutputOptions): string[] {
        const options = super.optionsForDemangler(filters);
        if (filters !== undefined && !filters.verboseDemangling) {
            options.push('--no-verbose');
        }
        return options;
    }

    // Override the IR file name method for rustc because the output file is different from clang.
    override getIrOutputFilename(inputFilename: string, filters: ParseFiltersAndOutputOptions): string {
        const outputFilename = this.getOutputFilename(path.dirname(inputFilename), this.outputFilebase);
        // As per #4054, if we are asked for binary mode, the output will be in the .s file, no .ll will be emited
        if (!filters.binary) {
            return changeExtension(outputFilename, '.ll');
        }
        return outputFilename;
    }

    override getArgumentParserClass() {
        return RustParser;
    }

    override isCfgCompiler() {
        return true;
    }

    override processExecutionResult(input: UnprocessedExecResult, inputFilename?: string): BasicExecutionResult {
        return {
            ...input,
            stdout: parseRustOutput(input.stdout, inputFilename),
            stderr: parseRustOutput(input.stderr, inputFilename),
        };
    }

    override buildExecutable(
        compiler: string,
        options: string[],
        inputFilename: string,
        execOptions: ExecutionOptionsWithEnv,
    ) {
        // bug #5630: in presence of `--emit mir=..` rustc does not produce an executable.
        const newOptions = options.filter(
            (opt, idx, allOpts) =>
                !(opt === '--emit' && allOpts[idx + 1].startsWith('mir=')) && !opt.startsWith('mir='),
        );
        return super.runCompiler(compiler, newOptions, inputFilename, execOptions);
    }

    override isOutputLikelyLlvmIr(options: string[]): boolean {
        const emitIndex = options.indexOf('--emit');
        return options.includes('--emit=llvm-ir') || (emitIndex >= 0 && options[emitIndex + 1] == 'llvm-ir');
    }
}