import type { Task, WorkflowStepResult, WorkflowStepPhase, StepStatus } from "@fusion/core";

/*
FNXC:WorkflowSteps 2026-06-25-00:00:
Graph-native workflow steps (plan U3). Workflow step status now comes entirely from the graph-written
`task.workflowStepResults` entries (keyed by node id === enabledWorkflowSteps[i]); the legacy
`/api/workflow-steps` DB-row name lookup was dropped, so step names resolve from `result.workflowStepName`
with a fallback to the raw id.

Render states (design-lens): the progress model distinguishes
- `pending` (enabled, never started — no `startedAt`)
- `running` (graph node active — `pending` status with a `startedAt` and no `completedAt`)
- `done` (passed)
- `advisory_failure` (non-blocking REVISE — amber, counts as completed; does not block merge)
- `failed` (blocking gate failure — red)
- `skipped`
Disabled optional steps are simply absent from `enabledWorkflowSteps`, so they never appear in the
counter/bar.
*/

export type UnifiedTaskProgressStatus = StepStatus | "failed" | "advisory_failure" | "running";

export interface UnifiedTaskProgressItem {
  id: string;
  name: string;
  status: UnifiedTaskProgressStatus;
  source: "step" | "workflow";
  phase: WorkflowStepPhase;
}

export interface UnifiedTaskProgress {
  total: number;
  completed: number;
  items: UnifiedTaskProgressItem[];
}

function mapWorkflowStatus(result: WorkflowStepResult): UnifiedTaskProgressStatus {
  switch (result.status) {
    case "passed":
      return "done";
    case "failed":
      return "failed";
    case "advisory_failure":
      return "advisory_failure";
    case "skipped":
      return "skipped";
    case "pending":
    default:
      // The graph upserts a `pending` entry when a step starts running. A started-but-not-completed
      // entry is the in-progress/`running` display state; a bare `pending` (no `startedAt`) is an
      // enabled step that has not begun yet.
      return result.startedAt && !result.completedAt ? "running" : "pending";
  }
}

function isCompleted(status: UnifiedTaskProgressStatus): boolean {
  // advisory_failure is non-blocking: the step ran and returned feedback, so it counts as completed
  // (overall progress reads complete when only advisory steps returned REVISE).
  return status === "done" || status === "skipped" || status === "advisory_failure";
}

function resolveWorkflowStepName(workflowStepId: string, result: WorkflowStepResult | undefined): string {
  const resultName = result?.workflowStepName?.trim();
  if (resultName) {
    return resultName;
  }
  return workflowStepId;
}

export function getUnifiedTaskProgress(
  task: Pick<Task, "steps" | "enabledWorkflowSteps" | "workflowStepResults">,
): UnifiedTaskProgress {
  const stepItems: UnifiedTaskProgressItem[] = (task.steps ?? []).map((step, index) => ({
    id: `step-${index}`,
    name: step.name,
    status: step.status,
    source: "step",
    phase: "pre-merge",
  }));

  const workflowResultsById = new Map(
    (task.workflowStepResults ?? []).map((result) => [result.workflowStepId, result] as const),
  );

  const workflowItems: UnifiedTaskProgressItem[] = (task.enabledWorkflowSteps ?? []).map((workflowStepId) => {
    const result = workflowResultsById.get(workflowStepId);
    return {
      id: `workflow-${workflowStepId}`,
      name: resolveWorkflowStepName(workflowStepId, result),
      status: result ? mapWorkflowStatus(result) : "pending",
      source: "workflow",
      phase: result?.phase ?? "pre-merge",
    };
  });

  const items = [...stepItems, ...workflowItems];
  const total = items.length;
  const completed = items.filter((item) => isCompleted(item.status)).length;

  return { total, completed, items };
}