"use strict";

function record(value) {
  return typeof value === "object" && value !== null && !Array.isArray(value) ? value : {};
}

function stringOrNull(value) {
  return typeof value === "string" && value.length > 0 ? value : null;
}

function stringArray(value) {
  return Array.isArray(value) && value.every((item) => typeof item === "string") ? value : null;
}

function digestFromImage(value) {
  if (typeof value !== "string" || !value.includes("@")) return null;
  return value.split("@").slice(1).join("@") || null;
}

function exactSkipMarker(records, event) {
  return [...records].reverse().find((item) => item.event === event
    && item.status === "skipped"
    && item.reason === "no-build-no-rollout-plan") || null;
}

function extractPacSourceObservation(recordsInput) {
  const records = Array.isArray(recordsInput) ? recordsInput.map(record) : [];
  const plan = [...records].reverse().find((item) => item.event === "g14-ci-plan") || null;
  const collectMarker = exactSkipMarker(records, "collect-artifacts");
  const promoteMarker = exactSkipMarker(records, "gitops-promote");
  if (plan === null && collectMarker === null && promoteMarker === null) return null;

  const affected = stringArray(plan?.affectedServices);
  const rollout = stringArray(plan?.rolloutServices);
  const build = stringArray(plan?.buildServices);
  const reused = stringArray(plan?.reusedServices);
  const sourceCommit = stringOrNull(plan?.sourceCommitId);
  const planShapeValid = affected !== null && rollout !== null && build !== null;
  const sourceCommitValid = sourceCommit !== null && /^[0-9a-f]{40}$/iu.test(sourceCommit);
  const noRuntimeChangePlan = planShapeValid
    && affected.length === 0
    && rollout.length === 0
    && build.length === 0;
  const noRuntimeChangeMarkers = collectMarker !== null && promoteMarker !== null;
  const skipMarkerSeen = collectMarker !== null || promoteMarker !== null;
  const skipMarkerConflict = skipMarkerSeen && !noRuntimeChangePlan;

  let mode = "inconsistent";
  let valid = false;
  let reason = "structured-plan-or-terminal-marker-is-incomplete";
  if (planShapeValid && sourceCommitValid && noRuntimeChangePlan && noRuntimeChangeMarkers) {
    mode = "no-runtime-change";
    valid = true;
    reason = "no-build-no-rollout-plan";
  } else if (planShapeValid && sourceCommitValid && !noRuntimeChangePlan && !skipMarkerConflict) {
    mode = "delivery";
    valid = true;
    reason = "artifact-or-runtime-delivery-required";
  } else if (!sourceCommitValid) {
    reason = "source-commit-invalid-or-missing";
  } else if (!planShapeValid) {
    reason = "delivery-plan-shape-invalid-or-missing";
  } else if (skipMarkerConflict) {
    reason = "no-runtime-change-marker-conflicts-with-delivery-plan";
  }

  return {
    schemaVersion: "v1",
    contract: "hwlab-g14-ci-plan",
    mode,
    valid,
    reason,
    sourceCommit,
    plan: {
      affectedServiceCount: affected?.length ?? null,
      rolloutServiceCount: rollout?.length ?? null,
      buildServiceCount: build?.length ?? null,
      reusedServiceCount: reused?.length ?? null,
    },
    terminal: {
      collectArtifacts: collectMarker === null ? "missing" : "no-build-no-rollout-plan",
      gitopsPromote: promoteMarker === null ? "missing" : "no-build-no-rollout-plan",
    },
    valuesPrinted: false,
  };
}

function evaluatePacStatus(inputValue) {
  const input = record(inputValue);
  const artifact = record(input.artifact);
  const argo = record(input.argo);
  const runtime = record(input.runtime);
  const sourceObservation = record(artifact.sourceObservation);
  const revisionRelation = record(argo.revisionRelation);
  const gitopsRelation = stringOrNull(revisionRelation.relation) || "unknown";
  const sourceCommit = stringOrNull(input.sourceCommit);
  const registryDigest = stringOrNull(input.registryDigest);
  const artifactDigest = stringOrNull(artifact.digest);
  const expectedDigest = registryDigest || artifactDigest;
  const runtimeImage = stringOrNull(runtime.image);
  const runtimeDigest = stringOrNull(runtime.digest) || digestFromImage(runtimeImage);
  const runtimeMatches = expectedDigest === null || runtimeDigest === expectedDigest;
  const runtimeReady = Number.isInteger(runtime.replicas)
    && runtime.replicas > 0
    && runtime.readyReplicas === runtime.replicas;
  const selectedArtifactDigests = [...new Set([
    artifactDigest,
    ...(Array.isArray(artifact.digests) ? artifact.digests : []),
  ].filter((value) => typeof value === "string" && value.length > 0))];
  const selectedArtifactMatchesRuntime = runtimeDigest !== null && selectedArtifactDigests.includes(runtimeDigest);
  const registryMatchesArtifact = registryDigest === null || artifactDigest === null || registryDigest === artifactDigest;
  const healthUrl = stringOrNull(input.healthUrl);
  const healthStatus = stringOrNull(input.healthStatus);
  const healthReady = healthUrl === null || healthStatus === "200";
  const gitopsReady = stringOrNull(artifact.gitopsCommit) !== null && stringOrNull(argo.revision) !== null;
  const gitopsRevisionAligned = gitopsRelation === "exact" || gitopsRelation === "descendant";
  const deliveryDisabled = artifact.imageStatus === "disabled";
  const deliverySkipped = artifact.imageStatus === "skipped";
  const sourceObservationMode = stringOrNull(sourceObservation.mode);
  const noRuntimeChange = sourceObservationMode === "no-runtime-change";
  const sourceObservationInconsistent = sourceObservationMode === "inconsistent"
    || (sourceObservationMode !== null && sourceObservation.valid !== true);
  const observationSourceCommit = stringOrNull(sourceObservation.sourceCommit);
  const observationSourceMatches = sourceCommit !== null && observationSourceCommit === sourceCommit;
  const retainedRevision = stringOrNull(argo.revision);
  const retainedDigestReady = runtimeDigest !== null && /^sha256:[0-9a-f]{64}$/iu.test(runtimeDigest);
  const retainedOutputConflict = noRuntimeChange
    && (stringOrNull(artifact.gitopsCommit) !== null
      || artifactDigest !== null
      || selectedArtifactDigests.length > 0);

  let code = "pac-diagnostics-not-applicable";
  let phase = "not-applicable";
  let ok = true;
  let hint = "consumer did not expose artifact or runtime alignment evidence";
  if (deliveryDisabled) {
    code = "pac-delivery-disabled";
    phase = "disabled";
    hint = "delivery is disabled by YAML; registry, GitOps and runtime artifacts are intentionally absent";
  } else if (!sourceCommit) {
    ok = false;
    code = "pac-source-unknown";
    phase = "source-unknown";
    hint = "latest PaC PipelineRun did not expose a source commit";
  } else if (sourceObservationInconsistent) {
    ok = false;
    code = "pac-source-observation-inconsistent";
    phase = "source-observation-inconsistent";
    hint = "structured delivery plan and no-runtime-change terminal markers are incomplete or contradictory";
  } else if (sourceObservationMode !== null && !observationSourceMatches) {
    ok = false;
    code = "pac-source-observation-mismatch";
    phase = "source-observation-mismatch";
    hint = "the structured no-runtime-change observation does not belong to the selected PipelineRun source commit";
  } else if (noRuntimeChange && retainedOutputConflict) {
    ok = false;
    code = "pac-retained-output-conflict";
    phase = "source-only-output-conflict";
    hint = "a no-runtime-change PipelineRun unexpectedly reported a new artifact or GitOps output";
  } else if (noRuntimeChange && retainedRevision === null) {
    ok = false;
    code = "pac-retained-gitops-missing";
    phase = "retained-gitops-missing";
    hint = "the no-runtime-change observation is valid but the retained Argo GitOps revision is missing";
  } else if (noRuntimeChange && (argo.sync !== "Synced" || argo.health !== "Healthy")) {
    ok = false;
    code = "pac-retained-argo-not-ready";
    phase = "retained-argo-not-ready";
    hint = "the no-runtime-change observation is valid but retained Argo is not Synced/Healthy";
  } else if (noRuntimeChange && gitopsRelation !== "retained") {
    ok = false;
    code = "pac-retained-revision-unproven";
    phase = "retained-revision-unproven";
    hint = "the retained GitOps revision was not linked to the structured no-runtime-change observation";
  } else if (noRuntimeChange && !runtimeReady) {
    ok = false;
    code = "pac-retained-runtime-not-ready";
    phase = "retained-runtime-not-ready";
    hint = "the retained runtime ready replicas do not match the desired replica count";
  } else if (noRuntimeChange && !retainedDigestReady) {
    ok = false;
    code = "pac-retained-runtime-digest-missing";
    phase = "retained-runtime-digest-missing";
    hint = "the retained runtime is not pinned to a visible sha256 digest";
  } else if (noRuntimeChange && !healthReady) {
    ok = false;
    code = "pac-retained-health-not-ready";
    phase = "retained-health-not-ready";
    hint = "the retained runtime health endpoint is not ready";
  } else if (noRuntimeChange) {
    code = "pac-ready-no-runtime-change";
    phase = "ready-no-runtime-change";
    hint = "the successful source observation requires no artifact, GitOps or runtime change; retained Argo and runtime provenance remain healthy";
  } else if (stringOrNull(input.imageRepository) !== null && input.registryPresent !== true) {
    ok = false;
    code = "pac-registry-missing";
    phase = "source-ready-registry-missing";
    hint = "PaC source commit is known but the configured registry tag is missing";
  } else if (!registryMatchesArtifact) {
    ok = false;
    code = "pac-artifact-registry-mismatch";
    phase = "artifact-registry-mismatch";
    hint = "PipelineRun artifact digest does not match the configured registry digest";
  } else if (!gitopsReady) {
    ok = false;
    code = "pac-gitops-missing";
    phase = "artifact-ready-gitops-missing";
    hint = "PipelineRun completed but its GitOps commit is not visible";
  } else if (argo.sync !== "Synced" || argo.health !== "Healthy") {
    ok = false;
    code = "pac-argo-not-ready";
    phase = "gitops-ready-argo-pending";
    hint = "GitOps exists but Argo is not Synced/Healthy";
  } else if (!gitopsRevisionAligned) {
    ok = false;
    code = `pac-argo-revision-${gitopsRelation}`;
    phase = `gitops-ready-argo-revision-${gitopsRelation}`;
    hint = `Argo revision relation is ${gitopsRelation}; only exact or commit-graph-proven descendant is deployable`;
  } else if (gitopsRelation === "descendant" && !selectedArtifactMatchesRuntime) {
    ok = false;
    code = "pac-descendant-artifact-runtime-mismatch";
    phase = "argo-descendant-runtime-mismatch";
    hint = "a GitOps descendant is ready only when the selected PipelineRun artifact digest exactly matches the runtime digest";
  } else if (!runtimeMatches) {
    ok = false;
    code = "pac-runtime-not-aligned";
    phase = "argo-ready-runtime-mismatch";
    hint = "runtime image digest does not match the artifact digest produced by the selected PipelineRun";
  } else if (!runtimeReady) {
    ok = false;
    code = "pac-runtime-not-ready";
    phase = "runtime-replicas-not-ready";
    hint = "runtime ready replicas do not match the desired replica count";
  } else if (!healthReady) {
    ok = false;
    code = "pac-health-not-ready";
    phase = "runtime-ready-health-pending";
    hint = "runtime image is aligned but the configured health endpoint is not ready";
  } else if (artifactDigest || selectedArtifactDigests.length > 0 || stringOrNull(input.imageRepository) !== null) {
    code = deliverySkipped
      ? "pac-ready-runtime-unchanged"
      : gitopsRelation === "descendant"
        ? "pac-ready-gitops-descendant"
        : "pac-ready-gitops-exact";
    phase = "ready";
    hint = deliverySkipped
      ? "YAML-declared runtime inputs are unchanged; the existing image, GitOps manifest, runtime and health remain aligned"
      : gitopsRelation === "descendant"
        ? "Argo is on a commit-graph-proven GitOps descendant and the selected artifact, runtime, Argo and health are aligned"
        : "Argo is on the exact selected GitOps commit and the artifact, runtime, Argo and health are aligned";
  }

  return {
    ok,
    code,
    phase,
    hint,
    sourceCommit,
    runtimeSourceCommit: stringOrNull(input.runtimeSourceCommit),
    imageRepository: stringOrNull(input.imageRepository),
    registryProbeBase: stringOrNull(input.registryProbeBase),
    imageTag: stringOrNull(input.imageTag),
    registry: {
      present: input.registryPresent === true,
      digest: registryDigest,
      url: stringOrNull(input.registryUrl),
    },
    selectedArtifactDigests,
    gitops: {
      branch: stringOrNull(input.gitopsBranch),
      manifestPath: stringOrNull(input.gitopsManifestPath),
      commit: noRuntimeChange ? retainedRevision : stringOrNull(artifact.gitopsCommit) || retainedRevision,
      revisionRelation,
    },
    argo: {
      sync: stringOrNull(argo.sync),
      health: stringOrNull(argo.health),
      revision: retainedRevision,
      repoURL: stringOrNull(argo.repoURL),
      targetRevision: stringOrNull(argo.targetRevision),
      revisionRelation,
    },
    runtime: {
      image: runtimeImage,
      digest: runtimeDigest,
      readyReplicas: runtime.readyReplicas ?? null,
      replicas: runtime.replicas ?? null,
    },
    health: { url: healthUrl, status: healthStatus, ready: healthReady },
    pipelineRun: stringOrNull(input.pipelineRun),
    deliveryDisabled,
    deliverySkipped,
    deliveryMode: noRuntimeChange ? "no-runtime-change" : sourceObservationMode || "delivery",
    sourceObservation: Object.keys(sourceObservation).length > 0 ? sourceObservation : null,
    provenance: noRuntimeChange ? {
      relation: "retained",
      sourceCommit,
      gitopsRevision: retainedRevision,
      runtimeImage,
      runtimeDigest,
      newArtifact: false,
      newGitopsRevision: false,
      runtimeChanged: false,
      valuesPrinted: false,
    } : {
      relation: gitopsRelation,
      sourceCommit,
      gitopsRevision: retainedRevision,
      runtimeImage,
      runtimeDigest,
      valuesPrinted: false,
    },
    valuesPrinted: false,
  };
}

function fixtureInput(overrides = {}) {
  const digest = `sha256:${"a".repeat(64)}`;
  const revision = "b".repeat(40);
  return {
    sourceCommit: "c".repeat(40),
    artifact: {},
    argo: {
      sync: "Synced",
      health: "Healthy",
      revision,
      revisionRelation: { relation: "retained", observedRevision: revision },
    },
    runtime: { image: `registry/service@${digest}`, digest, replicas: 1, readyReplicas: 1 },
    registryPresent: false,
    healthUrl: null,
    healthStatus: null,
    ...overrides,
  };
}

function noRuntimeChangeObservation(sourceCommit = "c".repeat(40)) {
  return extractPacSourceObservation([
    {
      event: "g14-ci-plan",
      sourceCommitId: sourceCommit,
      affectedServices: [],
      rolloutServices: [],
      buildServices: [],
      reusedServices: ["service"],
    },
    { event: "collect-artifacts", status: "skipped", reason: "no-build-no-rollout-plan" },
    { event: "gitops-promote", status: "skipped", reason: "no-build-no-rollout-plan" },
  ]);
}

function deliveryObservation(sourceCommit = "c".repeat(40)) {
  return extractPacSourceObservation([{
    event: "g14-ci-plan",
    sourceCommitId: sourceCommit,
    affectedServices: ["service"],
    rolloutServices: ["service"],
    buildServices: ["service"],
    reusedServices: [],
  }]);
}

function runPacStatusFixtureChecks() {
  const digestA = `sha256:${"a".repeat(64)}`;
  const digestD = `sha256:${"d".repeat(64)}`;
  const revision = "b".repeat(40);
  const retained = noRuntimeChangeObservation();
  const delivery = deliveryObservation();
  const exactArgo = { sync: "Synced", health: "Healthy", revision, revisionRelation: { relation: "exact", expectedRevision: revision, observedRevision: revision } };
  const cases = [
    {
      id: "retained-ready",
      expectedOk: true,
      expectedCode: "pac-ready-no-runtime-change",
      input: fixtureInput({ artifact: { imageStatus: "retained", sourceObservation: retained } }),
    },
    {
      id: "retained-gitops-missing",
      expectedOk: false,
      expectedCode: "pac-retained-gitops-missing",
      input: fixtureInput({ artifact: { imageStatus: "retained", sourceObservation: retained }, argo: { sync: "Synced", health: "Healthy", revision: null, revisionRelation: { relation: "unknown" } } }),
    },
    {
      id: "delivery-ready-exact",
      expectedOk: true,
      expectedCode: "pac-ready-gitops-exact",
      input: fixtureInput({ artifact: { imageStatus: "built", digest: digestA, digests: [digestA], gitopsCommit: revision, sourceObservation: delivery }, argo: exactArgo, runtime: { image: `registry/service@${digestA}`, digest: digestA, replicas: 1, readyReplicas: 1 } }),
    },
    {
      id: "delivery-gitops-missing",
      expectedOk: false,
      expectedCode: "pac-gitops-missing",
      input: fixtureInput({ artifact: { imageStatus: "built", digest: digestA, sourceObservation: delivery }, argo: { sync: "Synced", health: "Healthy", revision: null, revisionRelation: { relation: "unknown" } } }),
    },
    {
      id: "delivery-runtime-mismatch",
      expectedOk: false,
      expectedCode: "pac-runtime-not-aligned",
      input: fixtureInput({ artifact: { imageStatus: "built", digest: digestA, digests: [digestA], gitopsCommit: revision, sourceObservation: delivery }, argo: exactArgo, runtime: { image: `registry/service@${digestD}`, digest: digestD, replicas: 1, readyReplicas: 1 } }),
    },
    {
      id: "incomplete-no-runtime-change-markers",
      expectedOk: false,
      expectedCode: "pac-source-observation-inconsistent",
      input: fixtureInput({ artifact: { sourceObservation: extractPacSourceObservation([{ event: "g14-ci-plan", sourceCommitId: "c".repeat(40), affectedServices: [], rolloutServices: [], buildServices: [], reusedServices: [] }]) } }),
    },
    {
      id: "retained-source-mismatch",
      expectedOk: false,
      expectedCode: "pac-source-observation-mismatch",
      input: fixtureInput({ sourceCommit: "e".repeat(40), artifact: { imageStatus: "retained", sourceObservation: retained } }),
    },
    {
      id: "delivery-one-sided-skip-conflict",
      expectedOk: false,
      expectedCode: "pac-source-observation-inconsistent",
      input: fixtureInput({ artifact: { sourceObservation: extractPacSourceObservation([
        { event: "g14-ci-plan", sourceCommitId: "c".repeat(40), affectedServices: ["service"], rolloutServices: ["service"], buildServices: ["service"], reusedServices: [] },
        { event: "gitops-promote", status: "skipped", reason: "no-build-no-rollout-plan" },
      ]) } }),
    },
  ];
  const checks = cases.map((item) => {
    const result = evaluatePacStatus(item.input);
    return {
      id: item.id,
      ok: result.ok === item.expectedOk && result.code === item.expectedCode,
      expectedOk: item.expectedOk,
      actualOk: result.ok,
      expectedCode: item.expectedCode,
      actualCode: result.code,
    };
  });
  return { ok: checks.every((item) => item.ok), checks, valuesPrinted: false };
}

module.exports = {
  evaluatePacStatus,
  extractPacSourceObservation,
  runPacStatusFixtureChecks,
};