import { spawn } from "node:child_process";
import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";
import type { AgentToolResult } from "@earendil-works/pi-agent-core";
import type { Message } from "@earendil-works/pi-ai";
import { StringEnum } from "@earendil-works/pi-ai";
import { type ExtensionAPI, getMarkdownTheme, withFileMutationQueue } from "@earendil-works/pi-coding-agent";
import { Container, Markdown, Spacer, Text } from "@earendil-works/pi-tui";
import { Type } from "typebox";
import { type AgentConfig, type AgentScope, discoverAgents } from "./agents.ts";
import { AgentManager } from "./agent-manager.ts";
import { Workspace } from "./workspace.ts";
import { resolveAgentModel } from "./model-resolver.ts";
import { loadAgentSettings, registerAgentsCommand } from "./settings-page.ts";
export const MAX_PARALLEL_TASKS = 8;
export const MAX_CONCURRENCY = 4;
export const COLLAPSED_ITEM_COUNT = 10;
export const PER_TASK_OUTPUT_CAP = 50 * 1024;

export function formatTokens(count: number): string {
	if (count < 1000) return count.toString();
	if (count < 10000) return `${(count / 1000).toFixed(1)}k`;
	if (count < 1000000) return `${Math.round(count / 1000)}k`;
	return `${(count / 1000000).toFixed(1)}M`;
}

export function formatUsageStats(
	usage: {
		input: number;
		output: number;
		cacheRead: number;
		cacheWrite: number;
		cost: number;
		contextTokens?: number;
		turns?: number;
	},
	model?: string,
): string {
	const parts: string[] = [];
	if (usage.turns) parts.push(`${usage.turns} turn${usage.turns > 1 ? "s" : ""}`);
	if (usage.input) parts.push(`↑${formatTokens(usage.input)}`);
	if (usage.output) parts.push(`↓${formatTokens(usage.output)}`);
	if (usage.cacheRead) parts.push(`R${formatTokens(usage.cacheRead)}`);
	if (usage.cacheWrite) parts.push(`W${formatTokens(usage.cacheWrite)}`);
	if (usage.cost) parts.push(`$${usage.cost.toFixed(4)}`);
	if (usage.contextTokens && usage.contextTokens > 0) {
		parts.push(`ctx:${formatTokens(usage.contextTokens)}`);
	}
	if (model) parts.push(model);
	return parts.join(" ");
}

export function hasReportedUsage(usage: UsageStats): boolean {
	return usage.input > 0 || usage.output > 0 || usage.cacheRead > 0 || usage.cacheWrite > 0;
}

export function formatManagedUsage(usage: UsageStats, compact = false): string {
	const turns = compact ? `${usage.turns}t` : `${usage.turns} turn${usage.turns === 1 ? "" : "s"}`;
	if (usage.turns > 0 && !hasReportedUsage(usage)) return `${turns}, usage unavailable`;

	const parts = [turns];
	if (usage.input) parts.push(`↑${formatTokens(usage.input)}`);
	if (usage.output) parts.push(`↓${formatTokens(usage.output)}`);
	if (usage.cacheRead) parts.push(`cached ${formatTokens(usage.cacheRead)}`);
	if (usage.cacheWrite) parts.push(`cache write ${formatTokens(usage.cacheWrite)}`);
	parts.push(usage.cost > 0 ? `$${usage.cost.toFixed(4)}` : "cost unavailable");
	return parts.join(compact ? " " : ", ");
}

export function formatManagedCost(usage: UsageStats): string {
	if (usage.turns > 0 && !hasReportedUsage(usage)) return "Unavailable (provider did not report usage)";
	if (usage.cost === 0 && hasReportedUsage(usage)) return "Unavailable (pricing is not configured or provider did not report cost)";
	return `$${usage.cost.toFixed(4)}`;
}

export function formatManagedTokens(usage: UsageStats): string {
	if (usage.turns > 0 && !hasReportedUsage(usage)) return "Unavailable (provider did not report usage)";
	const cache = usage.cacheRead || usage.cacheWrite
		? `, ${usage.cacheRead} cache read, ${usage.cacheWrite} cache write`
		: "";
	return `${usage.input} input, ${usage.output} output${cache}`;
}

export function formatToolCall(
	toolName: string,
	args: Record<string, unknown>,
	themeFg: (color: any, text: string) => string,
): string {
	const shortenPath = (p: string) => {
		const home = os.homedir();
		return p.startsWith(home) ? `~${p.slice(home.length)}` : p;
	};

	switch (toolName) {
		case "bash": {
			const command = (args.command as string) || "...";
			const preview = command.length > 60 ? `${command.slice(0, 60)}...` : command;
			return themeFg("muted", "$ ") + themeFg("toolOutput", preview);
		}
		case "read": {
			const rawPath = (args.file_path || args.path || "...") as string;
			const filePath = shortenPath(rawPath);
			const offset = args.offset as number | undefined;
			const limit = args.limit as number | undefined;
			let text = themeFg("accent", filePath);
			if (offset !== undefined || limit !== undefined) {
				const startLine = offset ?? 1;
				const endLine = limit !== undefined ? startLine + limit - 1 : "";
				text += themeFg("warning", `:${startLine}${endLine ? `-${endLine}` : ""}`);
			}
			return themeFg("muted", "read ") + text;
		}
		case "write": {
			const rawPath = (args.file_path || args.path || "...") as string;
			const filePath = shortenPath(rawPath);
			const content = (args.content || "") as string;
			const lines = content.split("\n").length;
			let text = themeFg("muted", "write ") + themeFg("accent", filePath);
			if (lines > 1) text += themeFg("dim", ` (${lines} lines)`);
			return text;
		}
		case "edit": {
			const rawPath = (args.file_path || args.path || "...") as string;
			return themeFg("muted", "edit ") + themeFg("accent", shortenPath(rawPath));
		}
		case "ls": {
			const rawPath = (args.path || ".") as string;
			return themeFg("muted", "ls ") + themeFg("accent", shortenPath(rawPath));
		}
		case "find": {
			const pattern = (args.pattern || "*") as string;
			const rawPath = (args.path || ".") as string;
			return themeFg("muted", "find ") + themeFg("accent", pattern) + themeFg("dim", ` in ${shortenPath(rawPath)}`);
		}
		case "grep": {
			const pattern = (args.pattern || "") as string;
			const rawPath = (args.path || ".") as string;
			return (
				themeFg("muted", "grep ") +
				themeFg("accent", `/${pattern}/`) +
				themeFg("dim", ` in ${shortenPath(rawPath)}`)
			);
		}
		default: {
			const argsStr = JSON.stringify(args);
			const preview = argsStr.length > 50 ? `${argsStr.slice(0, 50)}...` : argsStr;
			return themeFg("accent", toolName) + themeFg("dim", ` ${preview}`);
		}
	}
}

export interface UsageStats {
	input: number;
	output: number;
	cacheRead: number;
	cacheWrite: number;
	cost: number;
	contextTokens: number;
	turns: number;
}

export interface SingleResult {
	sessionFile?: string;
	agent: string;
	agentSource: "user" | "project" | "unknown";
	task: string;
	exitCode: number;
	messages: Message[];
	stderr: string;
	usage: UsageStats;
	model?: string;
	responseModel?: string;
	thinkingLevel?: string;
	stopReason?: string;
	errorMessage?: string;
	yieldReason?: string;
	step?: number;
}

export interface SubagentDetails {
	mode: "single" | "parallel" | "chain";
	agentScope: AgentScope;
	projectAgentsDir: string | null;
	results: SingleResult[];
}

export function getFinalOutput(messages: Message[]): string {
	for (let i = messages.length - 1; i >= 0; i--) {
		const msg = messages[i];
		if (msg.role === "assistant") {
			for (const part of msg.content) {
				if (part.type === "text") return part.text;
			}
		}
	}
	return "";
}

export function isFailedResult(result: SingleResult): boolean {
	return result.exitCode !== 0 || result.stopReason === "error" || result.stopReason === "aborted" || result.stopReason === "yielded";
}

export function getResultOutput(result: SingleResult): string {
	if (result.stopReason === "yielded") {
		const output = getFinalOutput(result.messages);
		return `${result.yieldReason ?? "Worker yielded its token tranche."}${result.sessionFile ? `\nSaved session: ${result.sessionFile}` : ""}${output ? `\n\n${output}` : ""}`;
	}
	if (isFailedResult(result)) {
		return result.errorMessage || result.stderr || getFinalOutput(result.messages) || "(no output)";
	}
	return getFinalOutput(result.messages) || "(no output)";
}

export function truncateParallelOutput(output: string): string {
	const byteLength = Buffer.byteLength(output, "utf8");
	if (byteLength <= PER_TASK_OUTPUT_CAP) return output;

	let truncated = output.slice(0, PER_TASK_OUTPUT_CAP);
	while (Buffer.byteLength(truncated, "utf8") > PER_TASK_OUTPUT_CAP) {
		truncated = truncated.slice(0, -1);
	}
	return `${truncated}\n\n[Output truncated: ${byteLength - Buffer.byteLength(truncated, "utf8")} bytes omitted. Full output preserved in tool details.]`;
}

export type DisplayItem = { type: "text"; text: string } | { type: "toolCall"; name: string; args: Record<string, any> };

export function getDisplayItems(messages: Message[]): DisplayItem[] {
	const items: DisplayItem[] = [];
	for (const msg of messages) {
		if (msg.role === "assistant") {
			for (const part of msg.content) {
				if (part.type === "text") items.push({ type: "text", text: part.text });
				else if (part.type === "toolCall") items.push({ type: "toolCall", name: part.name, args: part.arguments });
			}
		}
	}
	return items;
}