import * as fs from "fs";
import * as path from "path";
import * as ts from "typescript";
import * as tss from "typescript/lib/tsserverlibrary";
import {
    SchematicContext,
    Tree,
    FileVisitor,
} from "@angular-devkit/schematics";
import {
    WorkspaceSchema,
    WorkspaceProject,
    ProjectType,
} from "@schematics/angular/utility/workspace-models";
import {
    ClassChanges,
    BindingChanges,
    SelectorChange,
    SelectorChanges,
    ThemeChanges,
    ImportsChanges,
    MemberChanges,
    ThemeChange,
    ThemeType,
} from "./schema";
import {
    getLanguageService,
    getRenamePositions,
    getIdentifierPositions,
    replaceMatch,
    createProjectService,
    isMemberIgniteUI,
    NG_LANG_SERVICE_PACKAGE_NAME,
    NG_CORE_PACKAGE_NAME,
    findMatches,
} from "./tsUtils";
import {
    getProjectPaths,
    getWorkspace,
    getProjects,
    escapeRegExp,
    getPackageManager,
    canResolvePackage,
    tryInstallPackage,
    tryUninstallPackage,
    getPackageVersion,
} from "./util";
import { ServerHost } from "./ServerHost";

const TSCONFIG_PATH = "tsconfig.json";

export enum InputPropertyType {
    EVAL = "eval",
    STRING = "string",
}
declare type TransformFunction = (args: BoundPropertyObject) => void;
export interface BoundPropertyObject {
    value: string;
    bindingType: InputPropertyType;
}

interface AppliedChange {
    overwrite: boolean;
    fileContent: string;
}

/* eslint-disable arrow-parens */
export class UpdateChanges {
    protected tsconfigPath = TSCONFIG_PATH;
    protected _projectService: tss.server.ProjectService;

    public _shouldInvokeLS = true;
    public get shouldInvokeLS(): boolean {
        return this._shouldInvokeLS;
    }
    public set shouldInvokeLS(val: boolean) {
        if (val === undefined || val === null) {
            // call LS by default
            this.shouldInvokeLS = true;
            return;
        }
        this._shouldInvokeLS = val;
    }

    public get projectService(): tss.server.ProjectService {
        if (!this._projectService) {
            this._projectService = createProjectService(this.serverHost);
            // Force Angular service to compile project on initial load w/ configure project
            // otherwise if the first compilation occurs on an HTML file the project won't have proper refs
            // and no actual angular metadata will be resolved for the rest of the migration
            const wsProject = this.resolveWorkspaceProject();
            if (!wsProject) {
                return null;
            }
            const mainRelPath = wsProject.architect?.build?.options["main"]
                ? path.join(
                      wsProject.root,
                      wsProject.architect?.build?.options["main"]
                  )
                : `src/main.ts`;
            // patch TSConfig so it includes angularOptions.strictTemplates
            // ivy ls requires this in order to function properly on templates
            this.patchTsConfig();
            const mainAbsPath = path.resolve(
                this._projectService.currentDirectory,
                mainRelPath
            );
            const scriptInfo =
                this._projectService.getOrCreateScriptInfoForNormalizedPath(
                    tss.server.toNormalizedPath(mainAbsPath),
                    false
                );
            this._projectService.openClientFile(scriptInfo.fileName);

            const project = this._projectService.findProject(
                scriptInfo.containingProjects[0].projectName
            );
            project.getLanguageService().getSemanticDiagnostics(mainAbsPath);
        }

        return this._projectService;
    }

    protected serverHost: ServerHost;
    protected workspace: WorkspaceSchema;
    protected sourcePaths: string[];
    protected classChanges: ClassChanges;
    protected outputChanges: BindingChanges;
    protected inputChanges: BindingChanges;
    protected selectorChanges: SelectorChanges;
    protected themeChanges: ThemeChanges;
    protected importsChanges: ImportsChanges;
    protected membersChanges: MemberChanges;
    protected conditionFunctions: Map<string, (...args) => any> = new Map<
        string,
        (...args) => any
    >();
    protected valueTransforms: Map<string, TransformFunction> = new Map<
        string,
        TransformFunction
    >();

    private _templateFiles: string[] = [];
    private _initialTsConfig = "";

    public get templateFiles(): string[] {
        if (!this._templateFiles.length) {
            // https://github.com/angular/devkit/blob/master/packages/angular_devkit/schematics/src/tree/filesystem.ts
            this.sourceDirsVisitor((fulPath, entry) => {
                if (fulPath.endsWith("component.html")) {
                    this._templateFiles.push(entry.path);
                }
            });
        }
        return this._templateFiles;
    }

    private _tsFiles: string[] = [];
    public get tsFiles(): string[] {
        if (!this._tsFiles.length) {
            this.sourceDirsVisitor((fulPath, entry) => {
                if (fulPath.endsWith(".ts")) {
                    this._tsFiles.push(entry.path);
                }
            });
        }
        return this._tsFiles;
    }

    private _sassFiles: string[] = [];
    /** Sass (both .scss and .sass) files in the project being updated. */
    public get sassFiles(): string[] {
        if (!this._sassFiles.length) {
            // files can be outside the app prefix, so start from sourceRoot
            // also ignore schematics `styleext` as Sass can be used regardless
            const sourceDirs = getProjects(this.workspace)
                .map((x) => x.sourceRoot)
                .filter((x) => x);
            this.sourceDirsVisitor((fulPath, entry) => {
                if (fulPath.endsWith(".scss") || fulPath.endsWith(".sass")) {
                    this._sassFiles.push(entry.path);
                }
            }, sourceDirs);
        }
        return this._sassFiles;
    }

    private _service: ts.LanguageService;
    public get service(): ts.LanguageService {
        if (!this._service) {
            this._service = getLanguageService(this.tsFiles, this.host);
        }
        return this._service;
    }

    private _packageManager: "npm" | "yarn";
    private get packageManager(): "npm" | "yarn" {
        if (!this._packageManager) {
            this._packageManager = getPackageManager(this.host);
        }

        return this._packageManager;
    }

    /**
     * Create a new base schematic to apply changes
     *
     * @param rootPath Root folder for the schematic to read configs, pass __dirname
     */
    constructor(
        private rootPath: string,
        private host: Tree,
        private context?: SchematicContext
    ) {
        this.workspace = getWorkspace(host);
        this.sourcePaths = getProjectPaths(this.workspace);

        this.selectorChanges = this.loadConfig("selectors.json");
        this.classChanges = this.loadConfig("classes.json");
        this.outputChanges = this.loadConfig("outputs.json");
        this.inputChanges = this.loadConfig("inputs.json");
        this.themeChanges = this.loadConfig("theme-changes.json");
        this.importsChanges = this.loadConfig("imports.json");
        this.membersChanges = this.loadConfig("members.json");
        this.serverHost = new ServerHost(this.host);
    }

    /** Apply configured changes to the Host Tree */
    public applyChanges() {
        const shouldInstallPkg =
            this.membersChanges &&
            this.membersChanges.changes.length &&
            !canResolvePackage(NG_LANG_SERVICE_PACKAGE_NAME);
        if (shouldInstallPkg) {
            this.context.logger.info(
                `Installing temporary migration dependencies via ${this.packageManager}.`
            );
            // try and get an appropriate version of the package to install
            let targetVersion =
                getPackageVersion(NG_CORE_PACKAGE_NAME) || "latest";
            if (targetVersion.startsWith("11")) {
                // TODO: Temporary restrict 11 LS version, till update for new module loading
                targetVersion = "11.0.0";
            }
            tryInstallPackage(
                this.context,
                this.packageManager,
                `${NG_LANG_SERVICE_PACKAGE_NAME}@${targetVersion}`
            );
        }

        this.updateTemplateFiles();
        this.updateTsFiles();
        if (this.shouldInvokeLS) {
            this.updateMembers();
        }
        /** Sass files */
        if (this.themeChanges && this.themeChanges.changes.length) {
            for (const entryPath of this.sassFiles) {
                this.updateThemeProps(entryPath);
                this.updateSassVariables(entryPath);
                this.updateSassFunctionsAndMixins(entryPath);
            }
        }

        if (shouldInstallPkg) {
            this.context.logger.info(
                `Cleaning up temporary migration dependencies.`
            );
            tryUninstallPackage(
                this.context,
                this.packageManager,
                NG_LANG_SERVICE_PACKAGE_NAME
            );
        }

        // if tsconfig.json was patched, restore it
        if (this._initialTsConfig !== "") {
            this.host.overwrite(this.tsconfigPath, this._initialTsConfig);
        }
    }

    /** Add condition function. */
    public addCondition(
        conditionName: string,
        callback: (ownerMatch: string, path: string) => boolean
    ) {
        this.conditionFunctions.set(conditionName, callback);
    }

    public addValueTransform(
        functionName: string,
        callback: TransformFunction
    ) {
        this.valueTransforms.set(functionName, callback);
    }

    /** Path must be absolute. If calling externally, use this.getAbsolutePath */
    protected getDefaultLanguageService(
        entryPath: string
    ): tss.LanguageService | undefined {
        const project = this.getDefaultProjectForFile(entryPath);
        return project?.getLanguageService();
    }

    protected updateSelectors(entryPath: string) {
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;
        for (const change of this.selectorChanges.changes) {
            let searchPttrn = change.type === "component" ? "<" : "";
            searchPttrn += change.selector;
            if (fileContent.indexOf(searchPttrn) !== -1) {
                fileContent = this.applySelectorChange(fileContent, change);
                overwrite = true;
            }
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected applySelectorChange(
        fileContent: string,
        change: SelectorChange
    ): string {
        let regSource: string;
        let replace: string;
        switch (change.type) {
            case "component":
                if (change.remove) {
                    regSource = String.raw`\<${change.selector}[\s\S]*?\<\/${change.selector}\>`;
                    replace = "";
                } else {
                    regSource = String.raw`\<(\/?)${change.selector}(?=[\s\>])`;
                    replace = `<$1${change.replaceWith}`;
                }
                break;
            case "directive":
                if (change.remove) {
                    // Group match (\2) as variable as it looks like octal escape (error in strict)
                    regSource = String.raw`\s*?\[?${
                        change.selector
                    }\]?(=(["']).*?${"\\2"}(?=\s|\>))?`;
                    replace = "";
                } else {
                    regSource = change.selector;
                    replace = change.replaceWith;
                }
                break;
            default:
                break;
        }
        fileContent = fileContent.replace(new RegExp(regSource, "g"), replace);
        return fileContent;
    }

    protected updateClasses(entryPath: string) {
        let fileContent = this.host.read(entryPath).toString();
        const alreadyReplaced = new Set<string>();
        for (const change of this.classChanges.changes) {
            if (fileContent.indexOf(change.name) !== -1) {
                const positions = getRenamePositions(
                    entryPath,
                    change.name,
                    this.service
                );
                // loop backwards to preserve positions
                for (let i = positions.length; i--; ) {
                    const pos = positions[i];
                    // V.S. 18th May 2021: If several classes are renamed w/ the same import, erase them
                    // TODO: Refactor to make use of TSLS API instead of string replace
                    if (i === 0 && alreadyReplaced.has(change.replaceWith)) {
                        // only match the first trailing white space, right after the replace position
                        const trailingCommaWhiteSpace = new RegExp(
                            /,([\s]*)(?=(\s}))/
                        );
                        let afterReplace = fileContent.slice(pos.end);
                        const beforeReplace = fileContent.slice(0, pos.start);
                        const leadingComma = afterReplace[0] === "," ? 1 : 0;
                        // recalculate if needed
                        afterReplace = !leadingComma
                            ? afterReplace
                            : fileContent.slice(pos.end + leadingComma);
                        const doubleSpaceReplace =
                            beforeReplace[beforeReplace.length - 1].match(
                                /\s/
                            ) !== null && afterReplace[0].match(/\s/) !== null
                                ? 1
                                : 0;
                        fileContent = (
                            fileContent.slice(
                                0,
                                pos.start - doubleSpaceReplace
                            ) +
                            "" +
                            afterReplace
                        ).replace(trailingCommaWhiteSpace, "");
                    } else {
                        fileContent =
                            fileContent.slice(0, pos.start) +
                            change.replaceWith +
                            fileContent.slice(pos.end);
                    }
                }
                if (positions.length) {
                    // using a set should be a lot quicker that getting position for renames of replace
                    alreadyReplaced.add(change.replaceWith);
                    this.host.overwrite(entryPath, fileContent);
                }
            }
        }
    }

    protected updateBindings(
        entryPath: string,
        bindChanges: BindingChanges,
        type = BindingType.Output
    ) {
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;

        for (const change of bindChanges.changes) {
            if (
                fileContent.indexOf(change.owner.selector) === -1 ||
                fileContent.indexOf(change.name) === -1
            ) {
                continue;
            }

            let base: string;
            let replace: string;
            let searchPattern;

            if (type === BindingType.Output) {
                base = String.raw`\(${change.name}\)=(["'])(.*?)\1`;
                replace = `(${change.replaceWith})=$1$2$1`;
            } else {
                // Match both bound - [name] - and regular - name
                base = String.raw`(\s\[?)${change.name}(\s*\]?=)(["'])(.*?)\3`;
                replace = String.raw`$1${change.replaceWith}$2$3$4$3`;
            }

            let reg = new RegExp(base, "g");
            if (change.remove || change.moveBetweenElementTags) {
                // Group match (\1) as variable as it looks like octal escape (error in strict)
                reg = new RegExp(String.raw`\s*${base}(?=\s|\>)`, "g");
                replace = "";
            }
            switch (change.owner.type) {
                case "component":
                    searchPattern = String.raw`\<${change.owner.selector}(?=[\s\>])[^\>]*\>`;
                    break;
                case "directive":
                    searchPattern = String.raw`\<[^\>]*[\s\[]${change.owner.selector}[^\>]*\>`;
                    break;
            }

            const matches = fileContent.match(new RegExp(searchPattern, "g"));
            if (!matches) {
                continue;
            }

            for (const match of matches) {
                let replaceStatement = replace;
                if (
                    !this.areConditionsFulfilled(
                        match,
                        change.conditions,
                        entryPath
                    )
                ) {
                    continue;
                }

                if (change.moveBetweenElementTags) {
                    const moveMatch = match.match(reg);
                    fileContent = this.copyPropertyValueBetweenElementTags(
                        fileContent,
                        match,
                        moveMatch
                    );
                }

                if (change.valueTransform) {
                    const regExpMatch = match.match(new RegExp(base));
                    const bindingType =
                        regExpMatch && regExpMatch[1].endsWith("[")
                            ? InputPropertyType.EVAL
                            : InputPropertyType.STRING;
                    if (regExpMatch) {
                        const value = regExpMatch[4];
                        const transform = this.valueTransforms.get(
                            change.valueTransform
                        );
                        const args = { value, bindingType };
                        transform(args);
                        if (args.bindingType !== bindingType) {
                            replaceStatement =
                                args.bindingType === InputPropertyType.EVAL
                                    ? replaceStatement
                                          .replace(`$1`, `$1[`)
                                          .replace(`$2`, `]$2`)
                                    : replaceStatement
                                          .replace(
                                              `$1`,
                                              regExpMatch[1].replace("[", "")
                                          )
                                          .replace(
                                              "$2",
                                              regExpMatch[2].replace("]", "")
                                          );
                        }
                        replaceStatement = replaceStatement.replace(
                            "$4",
                            args.value
                        );
                    }
                }

                fileContent = fileContent.replace(
                    match,
                    match.replace(reg, replaceStatement)
                );
            }
            overwrite = true;
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected updateThemeProps(entryPath: string) {
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;
        for (const change of this.themeChanges.changes) {
            if (change.type !== ThemeType.Property) {
                continue;
            }
            if (fileContent.indexOf(change.owner) !== -1) {
                /** owner-func:( * ); */
                const searchPattern = String.raw`${change.owner}\([\s\S]+?\);`;
                const matches = fileContent.match(
                    new RegExp(searchPattern, "g")
                );
                if (!matches) {
                    continue;
                }
                for (const match of matches) {
                    if (match.indexOf(change.name) !== -1) {
                        const name = change.name.replace("$", "\\$");
                        const replaceWith = change.replaceWith?.replace(
                            "$",
                            "\\$"
                        );
                        const reg = new RegExp(String.raw`^\s*${name}:`);
                        const existing = new RegExp(
                            String.raw`${replaceWith}:`
                        );
                        const opening = `${change.owner}(`;
                        const closing = /\s*\);$/.exec(match).pop();
                        const body = match.substr(
                            opening.length,
                            match.length - opening.length - closing.length
                        );

                        let params = this.splitFunctionProps(body);
                        params = params.reduce((arr, param) => {
                            if (reg.test(param)) {
                                const duplicate =
                                    !!replaceWith &&
                                    arr.some((p) => existing.test(p));

                                if (!change.remove && !duplicate) {
                                    arr.push(
                                        param.replace(
                                            change.name,
                                            change.replaceWith
                                        )
                                    );
                                }
                            } else {
                                arr.push(param);
                            }
                            return arr;
                        }, []);

                        fileContent = fileContent.replace(
                            match,
                            opening + params.join(",") + closing
                        );
                        overwrite = true;
                    }
                }
            }
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected isNamedArgument(
        fileContent: string,
        i: number,
        occurrences: number[],
        change: ThemeChange
    ) {
        const openingBrackets = [];
        const closingBrackets = [];
        if (
            fileContent[occurrences[i] + change.name.length] !== ":" ||
            (fileContent[occurrences[i] + change.name.length] === " " &&
                fileContent[occurrences[i] + change.name.length + 1] === ":")
        ) {
            return false;
        }
        for (let j = occurrences[i]; j >= 0; j--) {
            if (fileContent[j] === ")") {
                closingBrackets.push(fileContent[j]);
            } else if (fileContent[j] === "(") {
                openingBrackets.push(fileContent[j]);
            }
        }

        return openingBrackets.length !== closingBrackets.length;
    }

    protected updateSassVariables(entryPath: string) {
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;
        const allowedStartCharacters = new RegExp("(:|,)s?", "g");
        // eslint-disable-next-line no-control-regex
        const allowedEndCharacters = new RegExp("[;),: \r\n]", "g");
        for (const change of this.themeChanges.changes) {
            if (change.type !== ThemeType.Variable) {
                continue;
            }
            if (!("owner" in change)) {
                const occurrences = findMatches(fileContent, change.name);
                for (let i = occurrences.length - 1; i >= 0; i--) {
                    const allowedStartEnd =
                        fileContent[occurrences[i] - 1].match(
                            allowedStartCharacters
                        ) ||
                        fileContent[occurrences[i] + change.name.length].match(
                            allowedEndCharacters
                        );
                    if (
                        allowedStartEnd &&
                        !this.isNamedArgument(
                            fileContent,
                            i,
                            occurrences,
                            change as ThemeChange
                        )
                    ) {
                        fileContent = replaceMatch(
                            fileContent,
                            change.name,
                            change.replaceWith,
                            occurrences[i]
                        );
                        overwrite = true;
                    }
                }
            }
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected updateSassFunctionsAndMixins(entryPath: string) {
        const aliases = this.getAliases(entryPath);
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;
        for (const change of this.themeChanges.changes) {
            if (
                change.type !== ThemeType.Function &&
                change.type !== ThemeType.Mixin
            ) {
                continue;
            }

            let occurrences: number[] = [];
            if (aliases.length > 0 && !aliases.includes("*")) {
                aliases.forEach(
                    (a) =>
                        (occurrences = occurrences.concat(
                            findMatches(fileContent, a + "." + change.name)
                        ))
                );
                if (occurrences.length > 0) {
                    ({ overwrite, fileContent } =
                        this.tryReplaceScssFunctionWithAlias(
                            occurrences,
                            aliases,
                            fileContent,
                            change,
                            overwrite
                        ));
                    continue;
                }
            }

            occurrences = findMatches(fileContent, change.name);
            if (occurrences.length > 0) {
                ({ overwrite, fileContent } = this.tryReplaceScssFunction(
                    occurrences,
                    fileContent,
                    change,
                    overwrite
                ));
            }
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected getAliases(entryPath: string) {
        const fileContent = this.host.read(entryPath).toString();
        // B.P. 18/05/22 #11577 - Use RegEx to distinguish themed imports.
        const matchers = [
            /@use(\s+)('|")igniteui-angular-sovn\/theming\2\1as\1(\w+)/g,
            /@use(\s+)('|")igniteui-angular-sovn\/theme\2\1as\1(\w+)/g,
            /@use(\s+)('|")igniteui-angular-sovn\/lib\/core\/styles\/themes\/index\2\1as\1(\w+)/g,
        ];

        const aliases = [];
        matchers.forEach((m) => {
            const match = m.exec(fileContent);
            if (match) {
                aliases.push(match[3]); // access the captured alias
            }
        });

        return aliases;
    }

    protected updateImports(entryPath: string) {
        let fileContent = this.host.read(entryPath).toString();
        let overwrite = false;

        for (const change of this.importsChanges.changes) {
            if (fileContent.indexOf(change.name) === -1) {
                continue;
            }

            const replace = escapeRegExp(change.replaceWith);
            const base = escapeRegExp(change.name);
            const reg = new RegExp(base, "g");

            fileContent = fileContent.replace(reg, replace);
            overwrite = true;
        }
        if (overwrite) {
            this.host.overwrite(entryPath, fileContent);
        }
    }

    protected updateClassMembers(
        entryPath: string,
        memberChanges: MemberChanges
    ): void {
        let content = this.host.read(entryPath).toString();
        const absPath = tss.server.toNormalizedPath(
            path.join(process.cwd(), entryPath)
        );
        // use the absolute path for ALL LS operations
        // do not overwrite the entryPath, as Tree operations require relative paths
        const changes = new Set<{ change; position }>();
        let langServ: tss.LanguageService;
        for (const change of memberChanges.changes) {
            if (!content.includes(change.member)) {
                continue;
            }

            langServ = langServ || this.getDefaultLanguageService(absPath);
            if (!langServ) {
                return;
            }
            let matches: number[];
            if (entryPath.endsWith(".ts")) {
                const source = langServ.getProgram().getSourceFile(absPath);
                matches = getIdentifierPositions(source, change.member).map(
                    (x) => x.start
                );
            } else {
                matches = findMatches(content, `.${change.member}`).map(
                    (pos) => pos + 1
                );
            }
            for (const matchPosition of matches) {
                if (
                    isMemberIgniteUI(change, langServ, absPath, matchPosition)
                ) {
                    changes.add({ change, position: matchPosition });
                }
            }
        }

        const changesArr = Array.from(changes)
            .sort((c, c1) => c.position - c1.position)
            .reverse();
        for (const fileChange of changesArr) {
            content = replaceMatch(
                content,
                fileChange.change.member,
                fileChange.change.replaceWith,
                fileChange.position
            );
        }

        if (changes.size) {
            this.host.overwrite(entryPath, content);
        }
    }

    // TODO: combine both functions
    private tryReplaceScssFunctionWithAlias(
        occurrences: number[],
        aliases: string[],
        fileContent: string,
        change: ThemeChange,
        overwrite: boolean
    ): AppliedChange {
        for (const alias of aliases) {
            const aliasLength = alias.length + 1; // + 1 because of the dot - alias.member
            for (let i = occurrences.length - 1; i >= 0; i--) {
                const isOpenParenthesis =
                    fileContent[
                        occurrences[i] + aliasLength + change.name.length
                    ] === "(";
                if (isOpenParenthesis) {
                    fileContent = replaceMatch(
                        fileContent,
                        change.name,
                        change.replaceWith,
                        occurrences[i] + aliasLength
                    );
                    overwrite = true;
                }
            }
        }

        return { overwrite, fileContent };
    }
    private tryReplaceScssFunction(
        occurrences: number[],
        fileContent: string,
        change: ThemeChange,
        overwrite: boolean
    ): AppliedChange {
        for (let i = occurrences.length - 1; i >= 0; i--) {
            const isOpenParenthesis =
                fileContent[occurrences[i] + change.name.length] === "(";
            if (isOpenParenthesis) {
                fileContent = replaceMatch(
                    fileContent,
                    change.name,
                    change.replaceWith,
                    occurrences[i]
                );
                overwrite = true;
            }
        }

        return { overwrite, fileContent };
    }

    private patchTsConfig(): void {
        this.ensureTsConfigPath();
        if (this.serverHost.fileExists(this.tsconfigPath)) {
            let originalContent = "";
            try {
                originalContent = this.serverHost.readFile(this.tsconfigPath);
            } catch {
                this.context?.logger.warn(
                    `Could not read ${this.tsconfigPath}. Some Angular Ivy features might be unavailable during migrations.`
                );
                return;
            }
            let content;
            // use ts parser as it handles jsonc-style files w/ comments
            const result = ts.parseConfigFileTextToJson(
                this.tsconfigPath,
                originalContent
            );
            if (!result.error) {
                content = result.config;
            } else {
                this.context?.logger.warn(
                    `Could not parse ${this.tsconfigPath}. Angular Ivy language service might be unavailable during migrations.`
                );
                this.context?.logger.warn(`Error:\n${result.error}`);
                return;
            }
            if (!content.angularCompilerOptions) {
                content.angularCompilerOptions = {};
            }
            if (!content.angularCompilerOptions.strictTemplates) {
                this.context?.logger.info(
                    `Adding 'angularCompilerOptions.strictTemplates' to ${this.tsconfigPath} for migration run.`
                );
                content.angularCompilerOptions.strictTemplates = true;
                this.host.overwrite(this.tsconfigPath, JSON.stringify(content));
                // store initial state and restore it once migrations are finished
                this._initialTsConfig = originalContent;
            }
        }
    }

    private ensureTsConfigPath(): void {
        if (this.host.exists(this.tsconfigPath)) {
            return;
        }

        // attempt to find a main tsconfig from workspace:
        const wsProject = this.workspace.projects[0];
        // technically could be per-project, but assuming there's at least one main tsconfig for IDE support
        const projectConfig = wsProject.architect?.build?.options["tsConfig"];

        if (!projectConfig || !this.host.exists(projectConfig)) {
            return;
        }
        if (path.posix.basename(projectConfig) === TSCONFIG_PATH) {
            // not project specific extended tsconfig, use directly
            this.tsconfigPath = projectConfig;
            return;
        }

        // look for base config through extends property
        const result = ts.parseConfigFileTextToJson(
            projectConfig,
            this.serverHost.readFile(projectConfig)
        );
        if (!result.error && result.config.extends) {
            this.tsconfigPath = path.posix.join(
                path.posix.dirname(projectConfig),
                result.config.extends
            );
        }
    }

    private loadConfig(configJson: string) {
        const filePath = path.join(this.rootPath, "changes", configJson);
        if (fs.existsSync(filePath)) {
            return JSON.parse(fs.readFileSync(filePath, "utf-8"));
        }
    }

    private areConditionsFulfilled(
        match: string,
        conditions: string[],
        entryPath: string
    ): boolean {
        if (conditions) {
            for (const condition of conditions) {
                if (
                    this.conditionFunctions &&
                    this.conditionFunctions.has(condition)
                ) {
                    const callback = this.conditionFunctions.get(condition);
                    if (callback && !callback(match, entryPath)) {
                        return false;
                    }
                }
            }
        }

        return true;
    }

    private copyPropertyValueBetweenElementTags(
        fileContent: string,
        ownerMatch: string,
        propertyMatchArray: RegExpMatchArray
    ): string {
        if (ownerMatch && propertyMatchArray && propertyMatchArray.length > 0) {
            const propMatch = propertyMatchArray[0].trim();
            const propValueMatch = propMatch.match(
                new RegExp(`=(["'])(.+?)${"\\1"}`)
            );
            if (propValueMatch && propValueMatch.length > 0) {
                const propValue = propValueMatch[propValueMatch.length - 1];

                if (propMatch.startsWith("[")) {
                    return fileContent.replace(
                        ownerMatch,
                        ownerMatch + `{{${propValue}}}`
                    );
                } else {
                    return fileContent.replace(
                        ownerMatch,
                        ownerMatch + propValue
                    );
                }
            }
        }

        return fileContent;
    }

    private sourceDirsVisitor(visitor: FileVisitor, dirs = this.sourcePaths) {
        for (const sourcePath of dirs) {
            const srcDir = this.host.getDir(sourcePath);
            srcDir.visit(visitor);
        }
    }

    /**
     * Safe split by `','`, considering possible inner function calls. E.g.:
     * ```
     * prop: inner-func(),
     * prop2: inner2(inner-param: 3, inner-param: inner-func(..))
     * ```
     */
    private splitFunctionProps(body: string): string[] {
        const parts = [];
        let lastIndex = 0;
        let level = 0;

        for (let i = 0; i < body.length; i++) {
            const char = body[i];
            switch (char) {
                case "(":
                    level++;
                    break;
                case ")":
                    level--;
                    break;
                case ",":
                    if (!level) {
                        parts.push(body.substring(lastIndex, i));
                        lastIndex = i + 1;
                    }
                    break;
                default:
                    break;
            }
        }
        parts.push(body.substring(lastIndex));
        return parts;
    }

    private updateTemplateFiles() {
        if (this.selectorChanges && this.selectorChanges.changes.length) {
            for (const entryPath of this.templateFiles) {
                this.updateSelectors(entryPath);
            }
        }
        if (this.outputChanges && this.outputChanges.changes.length) {
            // name change of output
            for (const entryPath of this.templateFiles) {
                this.updateBindings(entryPath, this.outputChanges);
            }
        }
        if (this.inputChanges && this.inputChanges.changes.length) {
            // name change of input
            for (const entryPath of this.templateFiles) {
                this.updateBindings(
                    entryPath,
                    this.inputChanges,
                    BindingType.Input
                );
            }
        }
    }

    private updateTsFiles() {
        if (this.classChanges && this.classChanges.changes.length) {
            // change class name
            for (const entryPath of this.tsFiles) {
                this.updateClasses(entryPath);
            }
        }
        if (this.importsChanges && this.importsChanges.changes.length) {
            // TODO: move logic to 7.0.2 migration
            for (const entryPath of this.tsFiles) {
                this.updateImports(entryPath);
            }
        }
    }

    private updateMembers() {
        if (this.membersChanges && this.membersChanges.changes.length) {
            const dirs = [...this.templateFiles, ...this.tsFiles];
            for (const entryPath of dirs) {
                this.updateClassMembers(entryPath, this.membersChanges);
            }
        }
    }

    private getDefaultProjectForFile(entryPath: string): tss.server.Project {
        const scriptInfo =
            this.projectService?.getOrCreateScriptInfoForNormalizedPath(
                tss.server.asNormalizedPath(entryPath),
                false
            );
        if (!scriptInfo) {
            return null;
        }
        this.projectService.openClientFile(scriptInfo.fileName);
        const project = this.projectService.findProject(
            scriptInfo.containingProjects[0].projectName
        );
        project.addMissingFileRoot(scriptInfo.fileName);
        return project;
    }

    private resolveWorkspaceProject(): WorkspaceProject<ProjectType> | null {
        let wsProject = this.workspace.projects[0];
        if (!wsProject) {
            const projectKeys = Object.keys(this.workspace.projects);
            if (!projectKeys.length) {
                this.context.logger.info(
                    `Could not resolve project from directory ${this.serverHost.getCurrentDirectory()}. Some migrations may not be applied.`
                );
                return null;
            }
            // get the first configured project in the workspace
            wsProject = this.workspace.projects[projectKeys[0]];
        }

        return wsProject;
    }
}

export enum BindingType {
    Output,
    Input,
}