/*
 * Copyright © 2020 Atomist, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { configurationValue } from "@atomist/automation-client/lib/configuration";
import { HandlerContext } from "@atomist/automation-client/lib/HandlerContext";
import { failure, HandlerResult, Success } from "@atomist/automation-client/lib/HandlerResult";
import { RemoteRepoRef } from "@atomist/automation-client/lib/operations/common/RepoId";
import { GitProject } from "@atomist/automation-client/lib/project/git/GitProject";
import { logger } from "@atomist/automation-client/lib/util/logger";
import * as _ from "lodash";
import * as path from "path";
import { AddressChannels } from "../../api/context/addressChannels";
import { createSkillContext } from "../../api/context/skillContext";
import { ExecuteGoalResult, isFailure } from "../../api/goal/ExecuteGoalResult";
import { Goal } from "../../api/goal/Goal";
import {
    ExecuteGoal,
    GoalInvocation,
    GoalProjectListenerEvent,
    GoalProjectListenerRegistration,
} from "../../api/goal/GoalInvocation";
import { ReportProgress } from "../../api/goal/progress/ReportProgress";
import { SdmGoalEvent } from "../../api/goal/SdmGoalEvent";
import { GoalImplementation } from "../../api/goal/support/GoalImplementationMapper";
import { GoalExecutionListener, GoalExecutionListenerInvocation } from "../../api/listener/GoalStatusListener";
import { SoftwareDeliveryMachineConfiguration } from "../../api/machine/SoftwareDeliveryMachineOptions";
import { AnyPush } from "../../api/mapping/support/commonPushTests";
import { InterpretLog } from "../../spi/log/InterpretedLog";
import { ProgressLog } from "../../spi/log/ProgressLog";
import { isLazyProjectLoader, LazyProject } from "../../spi/project/LazyProjectLoader";
import { ProjectLoader } from "../../spi/project/ProjectLoader";
import { SdmGoalState } from "../../typings/types";
import { format } from "../log/format";
import { WriteToAllProgressLog } from "../log/WriteToAllProgressLog";
import { spawnLog } from "../misc/child_process";
import { toToken } from "../misc/credentials/toToken";
import { reportFailureInterpretation } from "../misc/reportFailureInterpretation";
import { serializeResult } from "../misc/result";
import { ProjectListenerInvokingProjectLoader } from "../project/ProjectListenerInvokingProjectLoader";
import { mockGoalExecutor } from "./mock";
import { descriptionFromState, updateGoal } from "./storeGoals";

class GoalExecutionError extends Error {
    public readonly where: string;
    public readonly result?: ExecuteGoalResult;
    public readonly cause?: Error;

    constructor(params: { where: string; result?: ExecuteGoalResult; cause?: Error }) {
        super("Failure in " + params.where);
        Object.setPrototypeOf(this, new.target.prototype);
        this.where = params.where;
        this.result = params.result;
        this.cause = params.cause;
    }

    get description(): string {
        const resultDescription = this.result ? ` Result code ${this.result.code} ${this.result.message}` : "";
        const causeDescription = this.cause ? ` Caused by: ${this.cause.message}` : "";
        return `Failure in ${this.where}:${resultDescription}${causeDescription}`;
    }
}

/**
 * Central function to execute a goal with progress logging
 */
export async function executeGoal(
    rules: { projectLoader: ProjectLoader; goalExecutionListeners: GoalExecutionListener[] },
    implementation: GoalImplementation,
    gi: GoalInvocation,
): Promise<ExecuteGoalResult> {
    const { goal, goalEvent, addressChannels, progressLog, id, context, credentials, configuration, preferences } = gi;
    const { progressReporter, logInterpreter, projectListeners } = implementation;
    const implementationName = goalEvent.fulfillment.name;

    if (!!progressReporter) {
        gi.progressLog = new WriteToAllProgressLog(
            goalEvent.name,
            gi.progressLog,
            new ProgressReportingProgressLog(progressReporter, goalEvent, gi.context),
        );
    }

    const push = goalEvent.push;
    logger.info(`Starting goal '%s' on '%s/%s/%s'`, goalEvent.uniqueName, push.repo.owner, push.repo.name, push.branch);

    async function notifyGoalExecutionListeners(
        sge: SdmGoalEvent,
        result?: ExecuteGoalResult,
        error?: Error,
    ): Promise<void> {
        const inProcessGoalExecutionListenerInvocation: GoalExecutionListenerInvocation = {
            id,
            context,
            addressChannels,
            configuration,
            preferences,
            credentials,
            goal,
            goalEvent: sge,
            error,
            result,
            skill: createSkillContext(context),
        };
        await Promise.all(
            rules.goalExecutionListeners.map(gel => {
                try {
                    return gel(inProcessGoalExecutionListenerInvocation);
                } catch (e) {
                    logger.warn(`GoalExecutionListener failed: ${e.message}`);
                    logger.debug(e);
                    return undefined;
                }
            }),
        );
    }

    const inProcessGoalEvent = await markGoalInProcess({
        ctx: context,
        goalEvent,
        goal,
        progressLogUrl: progressLog.url,
    });
    await notifyGoalExecutionListeners(inProcessGoalEvent);

    try {
        const goalInvocation = prepareGoalInvocation(gi, projectListeners);

        // execute pre hook
        const preHookResult: ExecuteGoalResult =
            (await executeHook(rules, goalInvocation, inProcessGoalEvent, "pre").catch(async err => {
                throw new GoalExecutionError({ where: "executing pre-goal hook", cause: err });
            })) || Success;
        if (isFailure(preHookResult)) {
            throw new GoalExecutionError({ where: "executing pre-goal hook", result: preHookResult });
        }
        // execute the actual goal
        const goalResult: ExecuteGoalResult =
            (await prepareGoalExecutor(
                implementation,
                inProcessGoalEvent,
                configuration,
            )(goalInvocation).catch(async err => {
                throw new GoalExecutionError({ where: "executing goal", cause: err });
            })) || Success;
        if (isFailure(goalResult)) {
            throw new GoalExecutionError({ where: "executing goal", result: goalResult });
        }

        // execute post hook
        const postHookResult: ExecuteGoalResult =
            (await executeHook(rules, goalInvocation, inProcessGoalEvent, "post").catch(async err => {
                throw new GoalExecutionError({ where: "executing post-goal hook", cause: err });
            })) || Success;
        if (isFailure(postHookResult)) {
            throw new GoalExecutionError({ where: "executing post-goal hooks", result: postHookResult });
        }

        const result = {
            ...preHookResult,
            ...goalResult,
            ...postHookResult,
        };

        await notifyGoalExecutionListeners(
            {
                ...inProcessGoalEvent,
                state: SdmGoalState.success,
            },
            result,
        );

        logger.info("Goal '%s' completed with: %j", goalEvent.uniqueName, result);
        await markStatus({ context, goalEvent, goal, result, progressLogUrl: progressLog.url });
        return { ...result, code: 0 };
    } catch (err) {
        logger.warn("Error executing goal '%s': %s", goalEvent.uniqueName, err.message);
        const result = handleGitRefErrors({ code: 1, ...(err.result || {}) }, err);
        await notifyGoalExecutionListeners(
            {
                ...inProcessGoalEvent,
                state: result.state || SdmGoalState.failure,
            },
            result,
            err,
        );
        await reportGoalError(
            {
                goal,
                implementationName,
                addressChannels,
                progressLog,
                id,
                logInterpreter,
            },
            err,
        );
        await markStatus({
            context,
            goalEvent,
            goal,
            result,
            error: err,
            progressLogUrl: progressLog.url,
        });
        return failure(err);
    }
}

export async function executeHook(
    rules: { projectLoader: ProjectLoader },
    goalInvocation: GoalInvocation,
    sdmGoal: SdmGoalEvent,
    stage: "post" | "pre",
): Promise<HandlerResult> {
    const hook = goalToHookFile(sdmGoal, stage);

    // Check configuration to see if hooks should be skipped
    if (!configurationValue<boolean>("sdm.goal.hooks", false)) {
        return Success;
    }

    const { projectLoader } = rules;
    const { credentials, id, context, progressLog } = goalInvocation;
    return projectLoader.doWithProject(
        {
            credentials,
            id,
            context,
            readOnly: true,
            cloneOptions: { detachHead: true },
        },
        async p => {
            if (await p.hasFile(path.join(".atomist", "hooks", hook))) {
                progressLog.write("/--");
                progressLog.write(`Invoking goal hook: ${hook}`);

                const opts = {
                    cwd: path.join(p.baseDir, ".atomist", "hooks"),
                    env: {
                        ...process.env,
                        GITHUB_TOKEN: toToken(credentials),
                        ATOMIST_WORKSPACE: context.workspaceId,
                        ATOMIST_CORRELATION_ID: context.correlationId,
                        ATOMIST_REPO: sdmGoal.push.repo.name,
                        ATOMIST_OWNER: sdmGoal.push.repo.owner,
                    },
                    log: progressLog,
                };

                const cmd = path.join(p.baseDir, ".atomist", "hooks", hook);
                let result: HandlerResult = await spawnLog(cmd, [], opts);
                if (!result) {
                    result = Success;
                }

                progressLog.write(`Result: ${serializeResult(result)}`);
                progressLog.write("\\--");
                await progressLog.flush();
                return result;
            } else {
                return Success;
            }
        },
    );
}

function goalToHookFile(sdmGoal: SdmGoalEvent, prefix: string): string {
    return `${prefix}-${sdmGoal.environment.toLocaleLowerCase().slice(2)}-${sdmGoal.name
        .toLocaleLowerCase()
        .replace(" ", "_")}`;
}

export function markStatus(parameters: {
    context: HandlerContext;
    goalEvent: SdmGoalEvent;
    goal: Goal;
    result: ExecuteGoalResult;
    error?: Error;
    progressLogUrl: string;
}): Promise<void> {
    const { context, goalEvent, goal, result, error, progressLogUrl } = parameters;

    let newState = SdmGoalState.success;
    if (result.state) {
        newState = result.state;
    } else if (result.code !== 0) {
        newState = SdmGoalState.failure;
    } else if (goal.definition.approvalRequired) {
        newState = SdmGoalState.waiting_for_approval;
    }

    return updateGoal(context, goalEvent, {
        url: progressLogUrl,
        externalUrls: result.externalUrls || [],
        state: newState,
        phase: result.phase ? result.phase : goalEvent.phase,
        description: result.description ? result.description : descriptionFromState(goal, newState, goalEvent),
        error,
        data: result.data ? result.data : goalEvent.data,
    });
}

function handleGitRefErrors(result: ExecuteGoalResult, error: Error & any): ExecuteGoalResult {
    if (!!error?.cause?.stderr) {
        const err = error?.cause?.stderr;
        if (/Remote branch .* not found/.test(err)) {
            result.code = 0;
            result.state = SdmGoalState.canceled;
            result.phase = "branch not found";
        } else if (/reference is not a tree/.test(err)) {
            result.code = 0;
            result.state = SdmGoalState.canceled;
            result.phase = "sha not found";
        }
    }
    return result;
}

async function markGoalInProcess(parameters: {
    ctx: HandlerContext;
    goalEvent: SdmGoalEvent;
    goal: Goal;
    progressLogUrl: string;
}): Promise<SdmGoalEvent> {
    const { ctx, goalEvent, goal, progressLogUrl } = parameters;
    goalEvent.state = SdmGoalState.in_process;
    goalEvent.description = descriptionFromState(goal, SdmGoalState.in_process, goalEvent);
    goalEvent.url = progressLogUrl;
    await updateGoal(ctx, goalEvent, {
        url: progressLogUrl,
        description: descriptionFromState(goal, SdmGoalState.in_process, goalEvent),
        state: SdmGoalState.in_process,
    });
    return goalEvent;
}

/**
 * Report an error executing a goal and present a retry button
 * @return {Promise<void>}
 */
async function reportGoalError(
    parameters: {
        goal: Goal;
        implementationName: string;
        addressChannels: AddressChannels;
        progressLog: ProgressLog;
        id: RemoteRepoRef;
        logInterpreter: InterpretLog;
    },
    err: GoalExecutionError,
): Promise<void> {
    const { implementationName, addressChannels, progressLog, id, logInterpreter } = parameters;
    if (err.cause) {
        logger.warn(err.cause.stack);
        progressLog.write(err.cause.stack);
    } else if (err.result && (err.result as any).error) {
        logger.warn((err.result as any).error.stack);
        progressLog.write((err.result as any).error.stack);
    } else {
        logger.warn(err.stack);
    }
    progressLog.write("Error: " + (err.description || err.message) + "\n");

    const interpretation = logInterpreter(progressLog.log);
    // The executor might have information about the failure; report it in the channels
    if (interpretation) {
        if (!interpretation.doNotReportToUser) {
            await reportFailureInterpretation(
                implementationName,
                interpretation,
                { url: progressLog.url, log: progressLog.log },
                id,
                addressChannels,
            );
        }
    }
}

export function prepareGoalExecutor(
    gi: GoalImplementation,
    sdmGoal: SdmGoalEvent,
    configuration: SoftwareDeliveryMachineConfiguration,
): ExecuteGoal {
    const mge = mockGoalExecutor(gi.goal, sdmGoal, configuration);
    if (mge) {
        return mge;
    } else {
        return gi.goalExecutor;
    }
}

export function prepareGoalInvocation(
    gi: GoalInvocation,
    listeners: GoalProjectListenerRegistration | GoalProjectListenerRegistration[],
): GoalInvocation {
    let hs: GoalProjectListenerRegistration[] = listeners
        ? Array.isArray(listeners)
            ? listeners
            : [listeners]
        : ([] as GoalProjectListenerRegistration[]);

    if (isLazyProjectLoader(gi.configuration.sdm.projectLoader)) {
        // Register the materializing listener for LazyProject instances of those need to
        // get materialized before using in goal implementations
        const projectMaterializer = {
            name: "clone project",
            pushTest: AnyPush,
            events: [GoalProjectListenerEvent.before],
            listener: async (p: GitProject & LazyProject) => {
                if (!p.materialized()) {
                    // Trigger project materialization
                    await p.materialize();
                }
                return { code: 0 };
            },
        };
        hs = [projectMaterializer, ...hs];
    }

    if (hs.length === 0) {
        return gi;
    }

    const configuration = _.cloneDeep(gi.configuration);
    configuration.sdm.projectLoader = new ProjectListenerInvokingProjectLoader(gi, hs);

    const newGi: GoalInvocation = {
        ...gi,
        configuration,
    };
    return newGi;
}

/**
 * ProgressLog implementation that uses the configured ReportProgress
 * instance to report goal execution updates.
 */
class ProgressReportingProgressLog implements ProgressLog {
    public log: string;
    public readonly name: string;
    public url: string;

    constructor(
        private readonly progressReporter: ReportProgress,
        private readonly sdmGoal: SdmGoalEvent,
        private readonly context: HandlerContext,
    ) {
        this.name = sdmGoal.name;
    }

    public async close(): Promise<void> {
        return;
    }

    public async flush(): Promise<void> {
        return;
    }

    public async isAvailable(): Promise<boolean> {
        return true;
    }

    public write(msg: string, ...args: string[]): void {
        const progress = this.progressReporter(format(msg, ...args), this.sdmGoal);
        if (progress && progress.phase) {
            if (this.sdmGoal.phase !== progress.phase) {
                this.sdmGoal.phase = progress.phase;
                updateGoal(this.context, this.sdmGoal, {
                    state: this.sdmGoal.state,
                    phase: progress.phase,
                    description: this.sdmGoal.description,
                    url: this.sdmGoal.url,
                })
                    .then(() => {
                        // Intentionally empty
                    })
                    .catch(err => {
                        logger.debug(`Error occurred reporting progress: %s`, err.message);
                    });
            }
        }
    }
}