// Project + model persistence layer.
//
// Stores the full SysMLModel as a JSON snapshot per version, plus a changelog
// of applied ops. Reads return the latest snapshot; writes apply ops
// server-side and write a new snapshot + changelog row atomically.

import { prisma } from "./client";
import { applyOps } from "../sync/applyOps";
import { fromFixture } from "../sysml/fromFixture";
import { aristotleFixture } from "../fixtures/aristotle";
import type { SysMLModel } from "../sysml/model";
import type { ModelOp } from "../sync/ops";

export interface LoadResult {
  model: SysMLModel;
  version: number;
}

export async function loadProject(projectId: string): Promise<LoadResult> {
  // Auto-seed: if the project doesn't exist (or has no snapshot), bootstrap
  // it from the Aristotle fixture so the editor route always has data.
  const seeded = await ensureSeeded(projectId);
  const snapshot = await prisma.modelSnapshot.findFirst({
    where: { projectId: seeded.projectId },
    orderBy: { version: "desc" },
  });
  if (!snapshot) {
    throw new Error(`Project ${projectId} has no snapshots after seed — should not happen`);
  }
  return {
    model: JSON.parse(snapshot.json) as SysMLModel,
    version: snapshot.version,
  };
}

export interface ApplyResult {
  applied: boolean;
  model: SysMLModel;
  version: number;
  idMapping: Record<string, string>;
  errors: Array<{ opIndex: number; code: string; message: string }>;
}

export async function applyOpsToProject(
  projectId: string,
  ops: ModelOp[],
  expectedVersion: number | undefined,
  reason?: string
): Promise<ApplyResult> {
  return prisma.$transaction(async tx => {
    const latest = await tx.modelSnapshot.findFirst({
      where: { projectId },
      orderBy: { version: "desc" },
    });
    if (!latest) throw new Error(`No snapshot for project ${projectId}`);

    if (expectedVersion !== undefined && expectedVersion !== latest.version) {
      // Optimistic-concurrency miss; caller must resync.
      return {
        applied: false,
        model: JSON.parse(latest.json) as SysMLModel,
        version: latest.version,
        idMapping: {},
        errors: [{ opIndex: -1, code: "VERSION_MISMATCH", message: `Expected version ${expectedVersion}, server is ${latest.version}` }],
      };
    }

    const currentModel = JSON.parse(latest.json) as SysMLModel;
    const result = applyOps(currentModel, ops);
    if (!result.applied) {
      return {
        applied: false,
        model: currentModel,
        version: latest.version,
        idMapping: {},
        errors: result.errors,
      };
    }

    const newVersion = latest.version + 1;
    await tx.modelSnapshot.create({
      data: {
        projectId,
        version: newVersion,
        json: JSON.stringify(result.model),
      },
    });
    await tx.changelogEntry.create({
      data: {
        projectId,
        version: newVersion,
        ops: JSON.stringify(ops),
        reason,
      },
    });

    return {
      applied: true,
      model: result.model,
      version: newVersion,
      idMapping: result.idMapping,
      errors: [],
    };
  });
}

// ─── Seeding ─────────────────────────────────────────────────────────────

async function ensureSeeded(projectId: string): Promise<{ projectId: string }> {
  const existing = await prisma.project.findUnique({ where: { id: projectId } });
  if (existing) {
    // Make sure there's at least one snapshot
    const snapCount = await prisma.modelSnapshot.count({ where: { projectId } });
    if (snapCount > 0) return { projectId };
  }

  // Bootstrap with the Aristotle fixture
  const seedModel = fromFixture(aristotleFixture);
  await prisma.project.upsert({
    where: { id: projectId },
    update: {},
    create: {
      id: projectId,
      name: aristotleFixture.project.name,
      scope: aristotleFixture.project.scope,
      tagline: aristotleFixture.project.tagline,
    },
  });
  await prisma.modelSnapshot.create({
    data: {
      projectId,
      version: 1,
      json: JSON.stringify(seedModel),
    },
  });

  // Auto-create an opening Socrates thread so the dock has somewhere to talk.
  // Socrates' opening turn is generated lazily on first GET (so we don't
  // pin a model selection to seed time).
  await prisma.socratesThread.create({
    data: {
      projectId,
      title: "Active thread · " + aristotleFixture.project.name,
      status: "open",
    },
  });

  return { projectId };
}

// ─── Findings (M8) ───────────────────────────────────────────────────────

import type { Finding as DetectedFinding } from "../llm/detect";

export interface StoredFinding {
  id: string;
  kind: string;
  text: string;
  linkedElementIds: string[];
  confidence: number;
  severity: string | null;
  validationCode: string | null;
  status: string;
  modelVersion: number;
  provider: string | null;
  llmModel: string | null;
  createdAt: Date;
}

export async function listOpenFindings(projectId: string): Promise<StoredFinding[]> {
  const rows = await prisma.finding.findMany({
    where: { projectId, status: "open" },
    orderBy: [{ kind: "asc" }, { createdAt: "desc" }],
  });
  return rows.map(rowToFinding);
}

export async function replaceFindings(
  projectId: string,
  findings: DetectedFinding[],
  modelVersion: number,
  provider: string,
  llmModel: string
): Promise<StoredFinding[]> {
  return prisma.$transaction(async tx => {
    // Wipe previous open findings — re-running detection supersedes them.
    await tx.finding.deleteMany({ where: { projectId, status: "open" } });
    if (findings.length === 0) return [];

    const created = await Promise.all(
      findings.map(f =>
        tx.finding.create({
          data: {
            projectId,
            kind: f.kind,
            text: f.text,
            linkedElementIds: JSON.stringify(f.linkedElementIds),
            confidence: f.confidence,
            severity: f.severity ?? null,
            validationCode: f.validationCode ?? null,
            status: "open",
            modelVersion,
            provider,
            llmModel,
          },
        })
      )
    );
    return created.map(rowToFinding);
  });
}

export async function dismissFinding(findingId: string): Promise<void> {
  await prisma.finding.update({
    where: { id: findingId },
    data: { status: "dismissed" },
  });
}

interface FindingRow {
  id: string;
  kind: string;
  text: string;
  linkedElementIds: string;
  confidence: number;
  severity: string | null;
  validationCode: string | null;
  status: string;
  modelVersion: number;
  provider: string | null;
  llmModel: string | null;
  createdAt: Date;
}

function rowToFinding(row: FindingRow): StoredFinding {
  let linked: string[] = [];
  try {
    const parsed = JSON.parse(row.linkedElementIds);
    if (Array.isArray(parsed)) linked = parsed.filter((x): x is string => typeof x === "string");
  } catch {
    linked = [];
  }
  return {
    id: row.id,
    kind: row.kind,
    text: row.text,
    linkedElementIds: linked,
    confidence: row.confidence,
    severity: row.severity,
    validationCode: row.validationCode,
    status: row.status,
    modelVersion: row.modelVersion,
    provider: row.provider,
    llmModel: row.llmModel,
    createdAt: row.createdAt,
  };
}

// ─── Socrates threads ────────────────────────────────────────────────────

export async function getActiveThread(projectId: string): Promise<{ id: string; title: string | null; messages: Array<{ id: string; role: string; content: string; createdAt: Date }> } | null> {
  const thread = await prisma.socratesThread.findFirst({
    where: { projectId, status: "open" },
    orderBy: { updatedAt: "desc" },
    include: { messages: { orderBy: { createdAt: "asc" } } },
  });
  if (!thread) return null;
  return {
    id: thread.id,
    title: thread.title,
    messages: thread.messages.map(m => ({
      id: m.id,
      role: m.role,
      content: m.content,
      createdAt: m.createdAt,
    })),
  };
}