import type {
  DebugTranscriptRow,
  DebugTranscriptTextRole,
  DebugTranscriptTextRow,
  DebugTranscriptToolRow,
  DebugTranscriptToolStatus,
} from './types';

let rowCounter = 0;

const createRowId = (prefix: string) => `${prefix}_${Date.now()}_${++rowCounter}`;

const isTextRow = (
  row: DebugTranscriptRow | undefined | null
): row is DebugTranscriptTextRow => row?.kind === 'text';

const isToolRow = (
  row: DebugTranscriptRow | undefined | null
): row is DebugTranscriptToolRow => row?.kind === 'tool';

const findRowIndexById = (rows: DebugTranscriptRow[], rowId?: string | null) =>
  rowId ? rows.findIndex((row) => row.id === rowId) : -1;

const findAssistantRowIndexByResponseId = (rows: DebugTranscriptRow[], responseId?: string) => {
  if (!responseId) return -1;
  return rows.findIndex(
    (row) => isTextRow(row) && row.role === 'assistant' && row.responseId === responseId
  );
};

const findLastAssistantCandidateIndex = (
  rows: DebugTranscriptRow[],
  responseId?: string
) => {
  for (let i = rows.length - 1; i >= 0; i -= 1) {
    const row = rows[i];
    if (isTextRow(row) && row.role === 'assistant') {
      if (responseId && row.responseId && row.responseId !== responseId) {
        break;
      }
      return i;
    }
    if (isTextRow(row) && row.role === 'user') {
      break;
    }
  }

  return -1;
};

const createTextRow = ({
  role,
  text,
  turnId,
  utteranceId,
  responseId,
  ttfbMs,
  isStreaming,
}: {
  role: DebugTranscriptTextRole;
  text: string;
  turnId?: string;
  utteranceId?: string;
  responseId?: string;
  ttfbMs?: number;
  isStreaming?: boolean;
}): DebugTranscriptTextRow => ({
  kind: 'text',
  id: createRowId(role),
  role,
  text,
  ...(turnId ? { turnId } : {}),
  ...(utteranceId ? { utteranceId } : {}),
  ...(responseId ? { responseId } : {}),
  ...(typeof ttfbMs === 'number' ? { ttfbMs } : {}),
  ...(typeof isStreaming === 'boolean' ? { isStreaming } : {}),
});

const createToolRow = ({
  toolCallId,
  toolName,
  toolDisplayName,
  executor,
  turnId,
  utteranceId,
  responseId,
  source,
  status,
  args,
  result,
  error,
  rawCall,
  rawResult,
}: {
  toolCallId: string;
  toolName: string;
  toolDisplayName: string;
  executor: string;
  turnId?: string;
  utteranceId?: string;
  responseId?: string;
  source?: string;
  status: DebugTranscriptToolStatus;
  args?: unknown;
  result?: unknown;
  error?: unknown;
  rawCall?: unknown;
  rawResult?: unknown;
}): DebugTranscriptToolRow => ({
  kind: 'tool',
  id: toolCallId || createRowId('tool'),
  toolCallId,
  toolName,
  toolDisplayName,
  executor,
  ...(turnId ? { turnId } : {}),
  ...(utteranceId ? { utteranceId } : {}),
  ...(responseId ? { responseId } : {}),
  ...(source ? { source } : {}),
  status,
  ...(args !== undefined ? { args } : {}),
  ...(result !== undefined ? { result } : {}),
  ...(error !== undefined ? { error } : {}),
  ...(rawCall !== undefined ? { rawCall } : {}),
  ...(rawResult !== undefined ? { rawResult } : {}),
});

export const resetTranscriptRows = (): DebugTranscriptRow[] => [];

export const appendTextRow = (
  rows: DebugTranscriptRow[],
  {
    role,
    text,
    turnId,
    utteranceId,
    responseId,
    ttfbMs,
    isStreaming,
  }: {
    role: DebugTranscriptTextRole;
    text: string;
    turnId?: string;
    utteranceId?: string;
    responseId?: string;
    ttfbMs?: number;
    isStreaming?: boolean;
  }
): DebugTranscriptRow[] => [
  ...rows,
  createTextRow({ role, text, turnId, utteranceId, responseId, ttfbMs, isStreaming }),
];

export const appendNoticeRow = (rows: DebugTranscriptRow[], text: string) =>
  appendTextRow(rows, { role: 'notice', text, isStreaming: false });

export const updateUserDraftRow = (
  rows: DebugTranscriptRow[],
  {
    draftRowId,
    text,
    turnId,
    utteranceId,
  }: {
    draftRowId?: string | null;
    text: string;
    turnId?: string;
    utteranceId?: string;
  }
): { rows: DebugTranscriptRow[]; draftRowId: string } => {
  const rowIndex = findRowIndexById(rows, draftRowId);
  if (rowIndex !== -1) {
    const row = rows[rowIndex];
    if (isTextRow(row) && row.role === 'user') {
      const nextRows = [...rows];
      nextRows[rowIndex] = {
        ...row,
        text,
        turnId: row.turnId || turnId,
        utteranceId: row.utteranceId || utteranceId,
        isStreaming: true,
      };
      return { rows: nextRows, draftRowId: row.id };
    }
  }

  const nextRow = createTextRow({
    role: 'user',
    text,
    turnId,
    utteranceId,
    isStreaming: true,
  });
  return {
    rows: [...rows, nextRow],
    draftRowId: nextRow.id,
  };
};

export const finalizeUserDraftRow = (
  rows: DebugTranscriptRow[],
  {
    draftRowId,
    text,
    turnId,
    utteranceId,
  }: {
    draftRowId?: string | null;
    text: string;
    turnId?: string;
    utteranceId?: string;
  }
): { rows: DebugTranscriptRow[]; draftRowId: null } => {
  const rowIndex = findRowIndexById(rows, draftRowId);
  if (rowIndex !== -1) {
    const row = rows[rowIndex];
    if (isTextRow(row) && row.role === 'user') {
      const nextRows = [...rows];
      nextRows[rowIndex] = {
        ...row,
        text: text || row.text,
        turnId: row.turnId || turnId,
        utteranceId: row.utteranceId || utteranceId,
        isStreaming: false,
      };
      return { rows: nextRows, draftRowId: null };
    }
  }

  if (!text) {
    return { rows, draftRowId: null };
  }

  return {
    rows: appendTextRow(rows, {
      role: 'user',
      text,
      turnId,
      utteranceId,
      isStreaming: false,
    }),
    draftRowId: null,
  };
};

export const updateAssistantDeltaRow = (
  rows: DebugTranscriptRow[],
  {
    draftRowId,
    delta,
    turnId,
    utteranceId,
    responseId,
    ttfbMs,
  }: {
    draftRowId?: string | null;
    delta: string;
    turnId?: string;
    utteranceId?: string;
    responseId?: string;
    ttfbMs?: number;
  }
): { rows: DebugTranscriptRow[]; draftRowId: string } => {
  let rowIndex = findRowIndexById(rows, draftRowId);
  if (
    rowIndex !== -1 &&
    (!isTextRow(rows[rowIndex]) || rows[rowIndex].role !== 'assistant')
  ) {
    rowIndex = -1;
  }

  if (rowIndex === -1) {
    rowIndex = findAssistantRowIndexByResponseId(rows, responseId);
  }

  if (rowIndex === -1) {
    rowIndex = findLastAssistantCandidateIndex(rows, responseId);
  }

  if (rowIndex === -1) {
    const lastRow = rows[rows.length - 1];
    if (
      isTextRow(lastRow) &&
      lastRow.role === 'assistant' &&
      lastRow.text === delta &&
      lastRow.responseId === responseId
    ) {
      return {
        rows,
        draftRowId: lastRow.id,
      };
    }

    const nextRow = createTextRow({
      role: 'assistant',
      text: delta,
      turnId,
      utteranceId,
      responseId,
      ttfbMs,
      isStreaming: true,
    });
    return {
      rows: [...rows, nextRow],
      draftRowId: nextRow.id,
    };
  }

  const row = rows[rowIndex];
  if (!isTextRow(row) || row.role !== 'assistant') {
    return {
      rows,
      draftRowId: draftRowId || createRowId('assistant'),
    };
  }

  const nextRows = [...rows];
  nextRows[rowIndex] = {
    ...row,
    text: row.text + delta,
    turnId: row.turnId || turnId,
    utteranceId: row.utteranceId || utteranceId,
    responseId: row.responseId || responseId,
    ttfbMs: typeof row.ttfbMs === 'number' ? row.ttfbMs : ttfbMs,
    isStreaming: true,
  };

  return {
    rows: nextRows,
    draftRowId: row.id,
  };
};

export const finalizeAssistantTextRow = (
  rows: DebugTranscriptRow[],
  {
    draftRowId,
    text,
    turnId,
    utteranceId,
    responseId,
    ttfbMs,
  }: {
    draftRowId?: string | null;
    text: string;
    turnId?: string;
    utteranceId?: string;
    responseId?: string;
    ttfbMs?: number;
  }
): { rows: DebugTranscriptRow[]; draftRowId: null } => {
  let rowIndex = findRowIndexById(rows, draftRowId);
  if (
    rowIndex !== -1 &&
    (!isTextRow(rows[rowIndex]) || rows[rowIndex].role !== 'assistant')
  ) {
    rowIndex = -1;
  }

  if (rowIndex === -1) {
    rowIndex = findAssistantRowIndexByResponseId(rows, responseId);
  }

  if (rowIndex === -1) {
    rowIndex = findLastAssistantCandidateIndex(rows, responseId);
  }

  if (rowIndex !== -1) {
    const row = rows[rowIndex];
    if (isTextRow(row) && row.role === 'assistant') {
      const nextRows = [...rows];
      nextRows[rowIndex] = {
        ...row,
        text: text || row.text,
        turnId: row.turnId || turnId,
        utteranceId: row.utteranceId || utteranceId,
        responseId: row.responseId || responseId,
        ttfbMs: typeof row.ttfbMs === 'number' ? row.ttfbMs : ttfbMs,
        isStreaming: false,
      };
      return {
        rows: nextRows,
        draftRowId: null,
      };
    }
  }

  if (!text) {
    return { rows, draftRowId: null };
  }

  const lastRow = rows[rows.length - 1];
  if (
    isTextRow(lastRow) &&
    lastRow.role === 'assistant' &&
    (!responseId || !lastRow.responseId || lastRow.responseId === responseId)
  ) {
    if (lastRow.text === text) {
      return { rows, draftRowId: null };
    }

    if (text.startsWith(lastRow.text) || lastRow.text.startsWith(text)) {
      const nextRows = [...rows];
      nextRows[nextRows.length - 1] = {
        ...lastRow,
        text,
        turnId: lastRow.turnId || turnId,
        utteranceId: lastRow.utteranceId || utteranceId,
        responseId: lastRow.responseId || responseId,
        ttfbMs: typeof lastRow.ttfbMs === 'number' ? lastRow.ttfbMs : ttfbMs,
        isStreaming: false,
      };
      return {
        rows: nextRows,
        draftRowId: null,
      };
    }
  }

  return {
    rows: appendTextRow(rows, {
      role: 'assistant',
      text,
      turnId,
      utteranceId,
      responseId,
      ttfbMs,
      isStreaming: false,
    }),
    draftRowId: null,
  };
};

export const attachAssistantTtfb = (
  rows: DebugTranscriptRow[],
  {
    responseId,
    ttfbMs,
  }: {
    responseId?: string;
    ttfbMs: number;
  }
) => {
  const rowIndex =
    findAssistantRowIndexByResponseId(rows, responseId) !== -1
      ? findAssistantRowIndexByResponseId(rows, responseId)
      : findLastAssistantCandidateIndex(rows, responseId);

  if (rowIndex === -1) {
    return rows;
  }

  const row = rows[rowIndex];
  if (!isTextRow(row) || row.role !== 'assistant') {
    return rows;
  }

  const nextRows = [...rows];
  nextRows[rowIndex] = {
    ...row,
    ttfbMs,
  };
  return nextRows;
};

export const trimInterruptedResponseRows = (
  rows: DebugTranscriptRow[],
  responseId?: string
) => {
  if (!responseId) return rows;
  return rows.filter((row) => row.responseId !== responseId);
};

export const upsertToolCallRow = (
  rows: DebugTranscriptRow[],
  {
    toolCallId,
    toolName,
    toolDisplayName,
    executor,
    turnId,
    utteranceId,
    responseId,
    args,
    rawCall,
  }: {
    toolCallId: string;
    toolName: string;
    toolDisplayName: string;
    executor: string;
    turnId?: string;
    utteranceId?: string;
    responseId?: string;
    args?: unknown;
    rawCall?: unknown;
  }
) => {
  const rowIndex = rows.findIndex(
    (row) => isToolRow(row) && row.toolCallId === toolCallId
  );
  if (rowIndex === -1) {
    return [
      ...rows,
      createToolRow({
        toolCallId,
        toolName,
        toolDisplayName,
        executor,
        turnId,
        utteranceId,
        responseId,
        status: 'pending',
        args,
        rawCall,
      }),
    ];
  }

  const row = rows[rowIndex];
  if (!isToolRow(row)) {
    return rows;
  }

  const nextRows = [...rows];
  nextRows[rowIndex] = {
    ...row,
    toolName,
    toolDisplayName,
    executor,
    turnId: row.turnId || turnId,
    utteranceId: row.utteranceId || utteranceId,
    responseId: row.responseId || responseId,
    status: 'pending',
    args: args !== undefined ? args : row.args,
    rawCall: rawCall !== undefined ? rawCall : row.rawCall,
  };
  return nextRows;
};

export const normalizeToolStatus = (
  statusCode?: number,
  statusMessage?: string
): DebugTranscriptToolStatus => {
  if (statusCode === 504 || String(statusMessage || '').toLowerCase().includes('timeout')) {
    return 'timeout';
  }

  if (typeof statusCode === 'number' && statusCode >= 200 && statusCode < 300) {
    return 'success';
  }

  return 'error';
};

export const resolveToolResultRow = (
  rows: DebugTranscriptRow[],
  {
    toolCallId,
    toolName,
    toolDisplayName,
    executor,
    turnId,
    utteranceId,
    responseId,
    source,
    status,
    args,
    result,
    error,
    rawCall,
    rawResult,
  }: {
    toolCallId: string;
    toolName: string;
    toolDisplayName: string;
    executor?: string;
    turnId?: string;
    utteranceId?: string;
    responseId?: string;
    source?: string;
    status: DebugTranscriptToolStatus;
    args?: unknown;
    result?: unknown;
    error?: unknown;
    rawCall?: unknown;
    rawResult?: unknown;
  }
) => {
  const rowIndex = rows.findIndex(
    (row) => isToolRow(row) && row.toolCallId === toolCallId
  );
  if (rowIndex === -1) {
    return [
      ...rows,
      createToolRow({
        toolCallId,
        toolName,
        toolDisplayName,
        executor: executor || 'server',
        turnId,
        utteranceId,
        responseId,
        source,
        status,
        args,
        result,
        error,
        rawCall,
        rawResult,
      }),
    ];
  }

  const row = rows[rowIndex];
  if (!isToolRow(row)) {
    return rows;
  }

  const nextRows = [...rows];
  nextRows[rowIndex] = {
    ...row,
    toolName: toolName || row.toolName,
    toolDisplayName: toolDisplayName || row.toolDisplayName,
    executor: executor || row.executor,
    turnId: row.turnId || turnId,
    utteranceId: row.utteranceId || utteranceId,
    responseId: row.responseId || responseId,
    source: source || row.source,
    status,
    args: args !== undefined ? args : row.args,
    result: result !== undefined ? result : row.result,
    error,
    rawCall: rawCall !== undefined ? rawCall : row.rawCall,
    rawResult: rawResult !== undefined ? rawResult : row.rawResult,
  };
  return nextRows;
};