import type {
  DashboardUsageDaily,
  DashboardUsageByAgent,
  DashboardAgentRunTime,
} from "@multica/core/types";
import { estimateCost, estimateCostBreakdown } from "../runtimes/utils";

// ---------------------------------------------------------------------------
// Dashboard data aggregations
//
// The workspace dashboard returns the same per-(date, model) and
// per-(agent, model) shapes the runtime page does, so cost math reuses
// `estimateCost` / `estimateCostBreakdown` from the runtimes utils. What
// the runtimes view does with `aggregateByDate` (works on RuntimeUsage,
// which carries a `provider` field) we replicate here with a tighter
// type — fewer optional fields, less conditional logic on the consumer
// side.
// ---------------------------------------------------------------------------

export interface DailyCostStack {
  date: string;
  label: string;
  input: number;
  output: number;
  cacheWrite: number;
  total: number;
}

function formatDateLabel(d: string): string {
  // Anchor to local midnight so the formatted label matches the bucket the
  // server picked (which is already in workspace time). Pasting the raw
  // date as the body of `new Date()` would interpret it as UTC and shift
  // by the user's offset.
  const date = new Date(d + "T00:00:00");
  return `${date.getMonth() + 1}/${date.getDate()}`;
}

// Per-(date, model) rows → 1 row per date with cost broken into the three
// segments the stacked bar chart consumes. Stable sort by date asc so the
// chart x-axis is left-to-right oldest-to-newest.
export function aggregateDailyCost(usage: DashboardUsageDaily[]): DailyCostStack[] {
  const map = new Map<string, { input: number; output: number; cacheWrite: number }>();
  for (const u of usage) {
    const b = estimateCostBreakdown(u);
    const entry = map.get(u.date) ?? { input: 0, output: 0, cacheWrite: 0 };
    entry.input += b.input;
    entry.output += b.output;
    entry.cacheWrite += b.cacheWrite;
    map.set(u.date, entry);
  }
  const round = (n: number) => Math.round(n * 100) / 100;
  return [...map.entries()]
    .sort(([a], [b]) => a.localeCompare(b))
    .map(([date, s]) => {
      const input = round(s.input);
      const output = round(s.output);
      const cacheWrite = round(s.cacheWrite);
      return {
        date,
        label: formatDateLabel(date),
        input,
        output,
        cacheWrite,
        total: round(input + output + cacheWrite),
      };
    });
}

export interface DashboardTokenTotals {
  input: number;
  output: number;
  cacheRead: number;
  cacheWrite: number;
  cost: number;
  taskCount: number;
}

// Whole-window totals for the KPI tiles. taskCount sums DISTINCT task counts
// per row — these are already collapsed server-side per (date, model), so
// the value can over-count if the same task has tokens in two days; that's
// acceptable for a KPI ("rough volume") and the per-agent run-time card
// gives the precise figure.
export function computeDailyTotals(usage: DashboardUsageDaily[]): DashboardTokenTotals {
  return usage.reduce<DashboardTokenTotals>(
    (acc, u) => ({
      input: acc.input + u.input_tokens,
      output: acc.output + u.output_tokens,
      cacheRead: acc.cacheRead + u.cache_read_tokens,
      cacheWrite: acc.cacheWrite + u.cache_write_tokens,
      cost: acc.cost + estimateCost(u),
      taskCount: acc.taskCount + u.task_count,
    }),
    { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, cost: 0, taskCount: 0 },
  );
}

export interface AgentCostRow {
  agentId: string;
  tokens: number;
  cost: number;
  taskCount: number;
}

// Fold per-(agent, model) rows into one row per agent. Cost is the sum
// across this agent's models, which is the figure the user cares about.
// Sort by cost desc so the heaviest spender lands first.
export function aggregateAgentTokens(rows: DashboardUsageByAgent[]): AgentCostRow[] {
  const map = new Map<string, AgentCostRow>();
  for (const r of rows) {
    const entry = map.get(r.agent_id) ?? {
      agentId: r.agent_id,
      tokens: 0,
      cost: 0,
      taskCount: 0,
    };
    entry.tokens +=
      r.input_tokens + r.output_tokens + r.cache_read_tokens + r.cache_write_tokens;
    entry.cost += estimateCost(r);
    entry.taskCount += r.task_count;
    map.set(r.agent_id, entry);
  }
  return [...map.values()].sort((a, b) => b.cost - a.cost);
}

export interface AgentDashboardRow {
  agentId: string;
  tokens: number;
  cost: number;
  seconds: number;
  taskCount: number;
}

// Merge per-agent token totals with per-agent run-time totals into one
// row per agent.
//
// taskCount comes from `runTimeRows` when available — that rollup is a
// true per-agent distinct count (`COUNT(*)` on (agent, terminal-task) in
// SQL). The token rollup's per-(agent, model) counts double-count a task
// when it spans multiple models, so we only fall back to it for agents
// with no terminal run yet (in-flight tasks reported tokens but haven't
// completed). Sorted by cost desc, then run time desc.
export function mergeAgentDashboardRows(
  tokenRows: AgentCostRow[],
  runTimeRows: DashboardAgentRunTime[],
): AgentDashboardRow[] {
  const runTimeByAgent = new Map(
    runTimeRows.map((r) => [r.agent_id, r] as const),
  );
  const merged = new Map<string, AgentDashboardRow>();
  for (const r of tokenRows) {
    const rt = runTimeByAgent.get(r.agentId);
    merged.set(r.agentId, {
      agentId: r.agentId,
      tokens: r.tokens,
      cost: r.cost,
      seconds: rt?.total_seconds ?? 0,
      taskCount: rt ? rt.task_count : r.taskCount,
    });
  }
  // Agents with run-time rows but zero tokens still belong on the list
  // (a task that errored before producing usage). Their token columns
  // stay at 0.
  for (const r of runTimeRows) {
    if (merged.has(r.agent_id)) continue;
    merged.set(r.agent_id, {
      agentId: r.agent_id,
      tokens: 0,
      cost: 0,
      seconds: r.total_seconds,
      taskCount: r.task_count,
    });
  }
  return [...merged.values()].sort((a, b) => {
    if (b.cost !== a.cost) return b.cost - a.cost;
    return b.seconds - a.seconds;
  });
}

// Compact human duration: "1h 23m" / "12m 30s" / "45s" / "<1m". Used for
// the dashboard run-time KPI and the per-agent run-time column. Keeps two
// segments max — three segments adds visual noise without precision the
// dashboard actually needs.
export function formatDuration(seconds: number, lessThanMinuteLabel: string): string {
  if (seconds < 0 || !Number.isFinite(seconds)) return lessThanMinuteLabel;
  if (seconds < 60) {
    if (seconds < 1) return lessThanMinuteLabel;
    return `${Math.round(seconds)}s`;
  }
  const totalMinutes = Math.floor(seconds / 60);
  const hours = Math.floor(totalMinutes / 60);
  const mins = totalMinutes % 60;
  if (hours === 0) {
    const secs = Math.floor(seconds) % 60;
    return secs > 0 ? `${mins}m ${secs}s` : `${mins}m`;
  }
  if (hours >= 24) {
    const days = Math.floor(hours / 24);
    const h = hours % 24;
    return h > 0 ? `${days}d ${h}h` : `${days}d`;
  }
  return mins > 0 ? `${hours}h ${mins}m` : `${hours}h`;
}