/**
 * comments-ops operations.
 *
 * FNXC:StoreModularization 2026-06-25-00:00:
 * Extracted from the monolithic packages/core/src/store.ts as a pure
 * behavior-preserving refactor. Each function receives the TaskStore
 * instance as its first parameter and performs byte-identical work.
 */
import {TaskStore, storeLog} from "../store.js";
import {randomUUID} from "node:crypto";
import {readFile} from "node:fs/promises";
import {join} from "node:path";
import {existsSync} from "node:fs";
import type {ArchivedTaskDocumentAdditionInput, ArchivedTaskDocumentAdditionResult, Task, Column, TaskDocument, TaskDocumentCreateInput, TaskLogEntry, RunMutationContext} from "../types.js";
import {validateDocumentKey} from "../types.js";
import {ArchivedTaskDocumentPublicationRejectedError, validateArchivedTaskDocumentAddition, validateTaskDocumentPreconditions} from "../task-document-concurrency.js";
import "../builtin-traits.js";
import {toJsonNullable} from "../db.js";
import {__setTaskActivityLogLimitsForTesting, isBootstrapPromptStub} from "../task-store/comments.js";
import {getLiveTaskColumn, publishArchivedTaskDocumentAddition as publishArchivedTaskDocumentAdditionAsync, upsertTaskDocument as upsertTaskDocumentAsync} from "../task-store/async-comments-attachments.js";
import type {TaskDocumentRow} from "../task-store/row-types.js";

export async function addCommentImpl(store: TaskStore, id: string, text: string, author: string = "user", options?: { skipRefinement?: boolean; source?: "user" | "agent" | "github-review" | "github-review-comment"; externalId?: string; reviewState?: "APPROVED" | "CHANGES_REQUESTED" | "COMMENTED"; }, runContext?: RunMutationContext,): Promise<Task> {
    if (store.backendMode) {
      const layer = store.asyncLayer!;
      const state = await getLiveTaskColumn(layer.db, id, layer.projectId);
      if (state === "archived") throw new Error(`Task ${id} is archived — comments are read-only`);
      if (state === null) throw new Error(`Task ${id} not found`);
    }
    // Phase 1: Add comment under lock
    const task = await store.withTaskLock(id, async () => {
      const dir = store.taskDir(id);
      const task = await store.readTaskJson(dir);

      // Initialize log array if missing (for legacy tasks)
      if (!task.log) {
        task.log = [];
      }

      if (!task.comments) {
        task.comments = [];
      }

      const externalSource = options?.source;
      const externalId = options?.externalId;
      if (externalSource && externalId) {
        const existing = task.comments.find((entry) => entry.source === externalSource && entry.externalId === externalId);
        if (existing) {
          return task;
        }
      }

      // Generate unique ID: timestamp + random suffix for collision resistance
      const commentId = `${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
      const now = new Date().toISOString();

      const comment: import("../types.js").TaskComment = {
        id: commentId,
        text,
        author,
        createdAt: now,
        updatedAt: now,
        source: options?.source,
        externalId: options?.externalId,
        reviewState: options?.reviewState,
      };

      task.comments.push(comment);
      task.updatedAt = now;
      const logEntry: TaskLogEntry = {
        timestamp: task.updatedAt,
        action: `Comment added by ${author}`,
      };
      if (runContext) {
        logEntry.runContext = runContext;
      }
      task.log.push(logEntry);

      // When runContext is provided, record audit event atomically with task mutation
      if (runContext) {
        await store.atomicWriteTaskJsonWithAudit(dir, task, {
          taskId: task.id,
          agentId: runContext.agentId,
          runId: runContext.runId,
          domain: "database",
          mutationType: "task:comment",
          target: task.id,
          metadata: { author, commentId, source: options?.source ?? null, externalId: options?.externalId ?? null },
        });
      } else {
        await store.atomicWriteTaskJson(dir, task);
      }
      if (store.isWatching) store.taskCache.set(id, { ...task });

      store.emit("task:updated", task);
      return task;
    });

    const commentContextBase: Record<string, unknown> = {
      taskId: id,
      author,
      commentLength: text.length,
      column: task.column,
      priorStatus: task.status ?? null,
    };
    if (runContext) {
      commentContextBase.runId = runContext.runId;
      commentContextBase.agentId = runContext.agentId;
      if (runContext.source) {
        commentContextBase.runSource = runContext.source;
      }
    }

    // Phase 2: Auto-refinement OUTSIDE the lock (to avoid lock contention)
    // Only create refinement for user comments on done tasks.
    // This remains best-effort: failures are logged for observability but never
    // fail the comment add operation itself.
    // Steering comments skip refinement — they are injected into the agent stream instead.
    if (task.column === "done" && author === "user" && !options?.skipRefinement) {
      try {
        await store.refineTask(id, text);
      } catch (err) {
        storeLog.warn("Best-effort post-comment auto-refinement failed", {
          ...commentContextBase,
          phase: "addComment:auto-refinement",
          error: err instanceof Error ? err.message : String(err),
        });
      }
    }

    // Phase 3: user comments on already-planned, non-executing work should
    // trigger triage re-specification. This includes awaiting-approval
    // invalidation and todo/triage tasks that have a real non-bootstrap spec.
    // This remains best-effort: failures are logged for observability but
    // never fail the comment add operation itself.
    // Note: The `task` returned above reflects the state BEFORE this
    // transition. Callers that need the post-transition status should
    // re-read the task (e.g., via getTask).
    if (author === "user" && (task.column === "todo" || task.column === "triage")) {
      let hasRealPrompt = false;
      try {
        const promptPath = join(store.taskDir(id), "PROMPT.md");
        if (existsSync(promptPath)) {
          const prompt = await readFile(promptPath, "utf-8");
          hasRealPrompt = !isBootstrapPromptStub(prompt, task.id, task.title, task.description);
        }
      } catch (err) {
        storeLog.warn("Best-effort post-comment re-triage prompt-read failed", {
          ...commentContextBase,
          phase: "addComment:retriage-prompt-read",
          error: err instanceof Error ? err.message : String(err),
        });
      }

      const shouldInvalidateAwaitingApproval =
        task.column === "triage" && task.status === "awaiting-approval";
      const shouldRetriagePlannedTask = hasRealPrompt
        && (
          task.column === "todo"
          || (task.column === "triage" && task.status !== "awaiting-approval")
        );

      if (shouldInvalidateAwaitingApproval || shouldRetriagePlannedTask) {
        const phase = shouldInvalidateAwaitingApproval
          ? "addComment:awaiting-approval-invalidation"
          : "addComment:planned-task-retriage";
        const action = shouldInvalidateAwaitingApproval
          ? "User comment invalidated spec approval — task needs re-specification"
          : "User comment requested re-specification of planned task";
        let transitioned = false;

        try {
          await store.updateTask(id, { status: "needs-replan" });
          transitioned = true;
        } catch (err) {
          storeLog.warn("Best-effort post-comment re-triage failed", {
            ...commentContextBase,
            phase,
            stage: "status-update",
            nextStatus: "needs-replan",
            error: err instanceof Error ? err.message : String(err),
          });
        }

        if (transitioned) {
          try {
            await store.logEntry(id, action, text, runContext);
          } catch (err) {
            storeLog.warn("Best-effort post-comment re-triage failed", {
              ...commentContextBase,
              phase,
              stage: "post-invalidation-log-entry",
              nextStatus: "needs-replan",
              error: err instanceof Error ? err.message : String(err),
            });
          }
        }
      }
    }

    return task;
  }

export async function publishArchivedTaskDocumentAdditionImpl(
  store: TaskStore,
  taskId: string,
  input: ArchivedTaskDocumentAdditionInput,
): Promise<ArchivedTaskDocumentAdditionResult> {
  try {
    validateDocumentKey(input.key);
  } catch {
    throw new Error(`Invalid document key: "${input.key}". Must be 1-64 alphanumeric characters, hyphens, or underscores.`);
  }
  validateArchivedTaskDocumentAddition(input);
  if (!store.backendMode || !store.asyncLayer) {
    throw new ArchivedTaskDocumentPublicationRejectedError(
      "postgres-required",
      store.asyncLayer?.projectId ?? "__legacy_unscoped__",
      taskId,
      input.key,
    );
  }
  /*
  FNXC:ArchivedTaskDocumentPublication 2026-07-20-15:36:
  The dedicated facade deliberately returns the atomic PostgreSQL result directly. Unlike ordinary upsert it emits no task event and performs no citation scan, keeping archived parent, workflow, mission, and scheduler state inert.
  */
  return publishArchivedTaskDocumentAdditionAsync(store.asyncLayer, taskId, input);
}

export async function upsertTaskDocumentImpl(store: TaskStore, taskId: string, input: TaskDocumentCreateInput): Promise<TaskDocument> {
    try {
      validateDocumentKey(input.key);
    } catch {
      throw new Error(
        `Invalid document key: "${input.key}". Must be 1-64 alphanumeric characters, hyphens, or underscores.`,
      );
    }

    validateTaskDocumentPreconditions(input);

    // FNXC:RuntimeWorkflowAsync 2026-06-24-17:00:
    // Backend mode: delegate the core upsert (revision archive + update) to
    // upsertTaskDocumentAsync. The citation scanning and task:updated emission
    // happen after (best-effort, same as the SQLite path).
    if (store.backendMode) {
      const layer = store.asyncLayer!;
      const document = await upsertTaskDocumentAsync(layer, taskId, input);
      const task = await store.getTask(taskId);
      store.emit("task:updated", task);
      try {
        const citationInputs = store.scanAndRecordCitations(
          input.content,
          "task_document",
          `document:${taskId}:${input.key}:rev${document.revision}`,
          input.author ?? "user",
          taskId,
          document.updatedAt,
        );
        if (citationInputs.length > 0) {
          void store.recordGoalCitations(citationInputs);
        }
      } catch (err) {
        console.warn("[fusion] Failed to scan/record goal citations from task document:", err);
      }
      return document;
    }

    const taskExists = store.db.prepare(`SELECT id, "column" FROM tasks WHERE id = ? AND ${TaskStore.ACTIVE_TASKS_WHERE}`).get(taskId) as
      | { id: string; column: Column }
      | undefined;
    if (taskExists?.column === "archived") {
      throw new Error(`Task ${taskId} is archived — documents are read-only`);
    }
    if (!taskExists) {
      if (store.isTaskArchived(taskId)) {
        throw new Error(`Task ${taskId} is archived — documents are read-only`);
      }
      throw new Error(`Task ${taskId} not found`);
    }

    const now = new Date().toISOString();
    const author = input.author ?? "user";
    const metadata = toJsonNullable(input.metadata);

    const document = store.db.transaction(() => {
      const existing = store.db
        .prepare("SELECT * FROM task_documents WHERE taskId = ? AND key = ?")
        .get(taskId, input.key) as TaskDocumentRow | undefined;

      if (existing) {
        store.db.prepare(
          `INSERT INTO task_document_revisions (taskId, key, content, revision, author, metadata, createdAt)
           VALUES (?, ?, ?, ?, ?, ?, ?)`
        ).run(
          taskId,
          input.key,
          existing.content,
          existing.revision,
          existing.author,
          existing.metadata ?? null,
          now,
        );

        store.db.prepare(
          `UPDATE task_documents
           SET content = ?, revision = ?, author = ?, metadata = ?, updatedAt = ?
           WHERE taskId = ? AND key = ?`
        ).run(
          input.content,
          existing.revision + 1,
          author,
          metadata,
          now,
          taskId,
          input.key,
        );
      } else {
        store.db.prepare(
          `INSERT INTO task_documents (id, taskId, key, content, revision, author, metadata, createdAt, updatedAt)
           VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`
        ).run(
          randomUUID(),
          taskId,
          input.key,
          input.content,
          1,
          author,
          metadata,
          now,
          now,
        );
      }

      const row = store.db
        .prepare("SELECT * FROM task_documents WHERE taskId = ? AND key = ?")
        .get(taskId, input.key) as TaskDocumentRow | undefined;

      if (!row) {
        throw new Error(`Failed to upsert document ${input.key} for task ${taskId}`);
      }

      return store.rowToTaskDocument(row);
    });

    store.db.bumpLastModified();
    const task = await store.getTask(taskId);
    store.emit("task:updated", task);

    try {
      const citationInputs = store.scanAndRecordCitations(
        input.content,
        "task_document",
        `document:${taskId}:${input.key}:rev${document.revision}`,
        input.author ?? "user",
        taskId,
        document.updatedAt,
      );
      if (citationInputs.length > 0) {
        store.recordGoalCitations(citationInputs);
      }
    } catch (err) {
      console.warn("[fusion] Failed to scan/record goal citations from task document:", err);
    }

    return document;
  }