import type { Theme } from "@earendil-works/pi-coding-agent";
import { Key, matchesKey, truncateToWidth, visibleWidth, type Component, type TUI } from "@earendil-works/pi-tui";
import { cycleNumberOption, cycleOption, type CycleDirection } from "./settings-core.ts";
import type { ClusterConfig, ClusterLevel } from "./types.ts";

const LEVELS: ClusterLevel[] = ["high", "medium", "low"];
const THINKING_LEVELS = ["off", "minimal", "low", "medium", "high", "xhigh", "max"];
const WORKER_TOOLS = ["read", "grep", "find", "ls", "bash", "edit", "write"];
const REVIEWER_TOOLS = ["read", "grep", "find", "ls"];
const FOLLOW_MAIN = "跟随主 agent";

type SettingsView = "main" | "group" | "models" | "tools";
type Group = ClusterLevel | "reviewer" | "cluster";
type SettingRow = {
	id: string;
	label: string;
	description: string;
	kind: "model" | "thinking" | "tools" | "number" | "boolean" | "action";
	level?: ClusterLevel;
};

export interface AvailableModel {
	value: string;
	label: string;
	description: string;
	thinkingLevels: string[];
}

export interface ClusterSettingsCallbacks {
	onSave(config: ClusterConfig): Promise<void>;
	onClearLearningEvidence(): Promise<"cleared" | "empty" | "cancelled">;
	onClose(): void;
}

export class ClusterSettingsComponent implements Component {
	private readonly mainRows: Array<{ group: Group; label: string; description: string }> = [
		{ group: "high", label: "HIGH", description: "最高等级 worker 模型、推理、工具和超时" },
		{ group: "medium", label: "MEDIUM", description: "中等级 worker 模型、推理、工具和超时" },
		{ group: "low", label: "LOW", description: "低等级 worker 模型、推理、工具和超时" },
		{ group: "reviewer", label: "REVIEWER", description: "审核器模型、推理、只读工具和超时" },
		{ group: "cluster", label: "CLUSTER", description: "并发数、任务数、重试次数和学习参数" },
	];
	private view: SettingsView = "main";
	private selectedIndex = 0;
	private mainSelectedIndex = 0;
	private readonly groupSelectedIndexes: Record<Group, number> = { high: 0, medium: 0, low: 0, reviewer: 0, cluster: 0 };
	private selectedGroup: Group = "high";
	private subIndex = 0;
	private toolsTarget: ClusterLevel | "reviewer" = "low";
	private error = "";
	private message = "";
	private actionPending = false;
	private persistQueue = Promise.resolve();

	constructor(
		private readonly tui: TUI,
		private readonly theme: Theme,
		private readonly config: ClusterConfig,
		private readonly models: AvailableModel[],
		private readonly reviewerThinkingLevels: string[],
		private readonly callbacks: ClusterSettingsCallbacks,
	) {}

	render(width: number): string[] {
		const contentWidth = Math.max(1, width - 2);
		const content = this.view === "group" ? this.renderGroup(contentWidth) : this.view === "models" ? this.renderModels(contentWidth) : this.view === "tools" ? this.renderTools(contentWidth) : this.renderMain(contentWidth);
		if (width < 3) return content.map((line) => truncateToWidth(line, width, "", false));
		const border = "─".repeat(contentWidth);
		const title = "Subagent Cluster Settings";
		const titleWidth = visibleWidth(title);
		const topBorder = contentWidth >= titleWidth + 4
			? this.theme.fg("border", "╭─ ") + this.theme.fg("accent", title) + this.theme.fg("border", ` ${"─".repeat(contentWidth - titleWidth - 3)}╮`)
			: this.theme.fg("border", `╭${border}╮`);
		return [
			topBorder,
			...content.map((line) => this.theme.fg("border", "│") + truncateToWidth(line, contentWidth, "", true) + this.theme.fg("border", "│")),
			this.theme.fg("border", `╰${border}╯`),
		];
	}

	handleInput(data: string): void {
		if (this.actionPending) return;
		if (this.view === "models") return this.handleModels(data);
		if (this.view === "tools") return this.handleTools(data);
		if (matchesKey(data, Key.escape)) {
			if (this.view === "group") {
				this.groupSelectedIndexes[this.selectedGroup] = this.selectedIndex;
				this.selectedIndex = this.mainSelectedIndex;
				this.view = "main";
			} else this.callbacks.onClose();
			this.tui.requestRender();
			return;
		}
		const rows = this.view === "main" ? this.mainRows : this.groupRows(this.selectedGroup);
		if (matchesKey(data, Key.up) || data === "k") {
			this.selectedIndex = this.selectedIndex === 0 ? rows.length - 1 : this.selectedIndex - 1;
			this.tui.requestRender();
			return;
		}
		if (matchesKey(data, Key.down) || data === "j") {
			this.selectedIndex = this.selectedIndex === rows.length - 1 ? 0 : this.selectedIndex + 1;
			this.tui.requestRender();
			return;
		}
		if (this.view === "group" && (matchesKey(data, Key.left) || matchesKey(data, Key.right))) {
			const row = rows[this.selectedIndex] as SettingRow | undefined;
			this.adjustRow(row, matchesKey(data, Key.left) ? -1 : 1);
			this.tui.requestRender();
			return;
		}
		if (matchesKey(data, Key.enter) || matchesKey(data, Key.space)) this.activateRow(rows[this.selectedIndex]);
	}

	private adjustRow(row: SettingRow | undefined, direction: CycleDirection): void {
		if (row?.kind === "thinking") this.cycleThinking(row.id, direction);
		else if (row?.kind === "boolean") this.cycleBoolean(row.id, direction);
		else if (row?.kind === "number") this.cycleNumber(row.id, direction);
	}

	private activateRow(row: SettingRow | { group: Group } | undefined): void {
		if (!row) return;
		if ("group" in row) {
			this.mainSelectedIndex = this.selectedIndex;
			this.selectedGroup = row.group;
			this.selectedIndex = this.groupSelectedIndexes[row.group];
			this.view = "group";
			this.tui.requestRender();
			return;
		}
		if (row.kind === "model") {
			const options = this.modelOptions(row);
			this.view = "models";
			this.subIndex = Math.max(0, options.findIndex((model) => model.value === this.modelValue(row.id)));
			this.tui.requestRender();
			return;
		}
		if (row.kind === "tools") {
			this.toolsTarget = row.id === "reviewer.tools" ? "reviewer" : row.level ?? "low";
			this.view = "tools";
			this.subIndex = 0;
			this.tui.requestRender();
			return;
		}
		if (row.kind === "action") void this.clearLearningEvidence();
	}

	private groupRows(group: Group): SettingRow[] {
		if (group === "cluster") {
			return [
				{ id: "maxConcurrency", label: "Max concurrency", description: "同时运行的最大 worker 数量", kind: "number" },
				{ id: "maxTasks", label: "Max tasks", description: "单次集群允许的最大任务数量", kind: "number" },
				{ id: "maxRetriesPerLevel", label: "Retries per level", description: "自动升级前的同等级重试次数", kind: "number" },
				{ id: "learning.enabled", label: "Learning", description: "是否根据全局学习证据调整任务最低起始等级", kind: "boolean" },
				{ id: "learning.taskTypeUpgradeThreshold", label: "Task type threshold", description: "同一 taskType 需要多少个不同运行的有效升级证据", kind: "number" },
				{ id: "learning.historyRetentionDays", label: "History retention", description: "学习证据的有效天数", kind: "number" },
				{ id: "learning.clearEvidence", label: "Clear learning evidence", description: "清除所有项目共享的全部学习证据，此操作不可撤销", kind: "action" },
			];
		}
		if (group === "reviewer") {
			return [
				{ id: "reviewer.model", label: "Model", description: "审核器模型；留空表示跟随主 agent", kind: "model" },
				{ id: "reviewer.thinkingLevel", label: "Thinking level", description: "按审核器模型能力显示可用推理模式", kind: "thinking" },
				{ id: "reviewer.tools", label: "Tools", description: "审核器只能选择只读工具", kind: "tools" },
				{ id: "reviewer.timeoutMs", label: "Timeout", description: "单次审核超时时间", kind: "number" },
			];
		}
		return [
			{ id: `${group}.model`, label: "Model", description: "worker 使用的可用模型", kind: "model", level: group },
			{ id: `${group}.thinkingLevel`, label: "Thinking level", description: "按当前模型能力显示可用推理模式", kind: "thinking", level: group },
			{ id: `${group}.tools`, label: "Tools", description: "worker 可调用的工具", kind: "tools", level: group },
			{ id: `${group}.timeoutMs`, label: "Timeout", description: "单次 worker 超时时间", kind: "number", level: group },
		];
	}

	private handleModels(data: string): void {
		const row = this.groupRows(this.selectedGroup)[this.selectedIndex];
		const options = this.modelOptions(row);
		if (matchesKey(data, Key.escape)) {
			this.view = "group";
			this.tui.requestRender();
			return;
		}
		if (matchesKey(data, Key.up) || data === "k") this.subIndex = this.subIndex === 0 ? Math.max(0, options.length - 1) : this.subIndex - 1;
		else if (matchesKey(data, Key.down) || data === "j") this.subIndex = this.subIndex === options.length - 1 ? 0 : this.subIndex + 1;
		else if (matchesKey(data, Key.enter) && options[this.subIndex]) {
			const selected = options[this.subIndex];
			if (row?.id === "reviewer.model") {
				this.config.reviewer.model = selected.value || undefined;
				this.normalizeThinking("reviewer.thinkingLevel");
			} else if (row?.level) {
				this.config.levels[row.level].model = selected.value;
				this.normalizeThinking(`${row.level}.thinkingLevel`);
			}
			this.persist();
			this.view = "group";
		}
		this.tui.requestRender();
	}

	private handleTools(data: string): void {
		const tools = this.toolsForTarget();
		if (matchesKey(data, Key.escape)) {
			this.view = "group";
			this.tui.requestRender();
			return;
		}
		if (matchesKey(data, Key.up) || data === "k") this.subIndex = this.subIndex === 0 ? tools.length - 1 : this.subIndex - 1;
		else if (matchesKey(data, Key.down) || data === "j") this.subIndex = this.subIndex === tools.length - 1 ? 0 : this.subIndex + 1;
		else if (matchesKey(data, Key.space)) {
			const tool = tools[this.subIndex];
			const selected = this.selectedTools();
			this.setSelectedTools(selected.includes(tool) ? selected.filter((item) => item !== tool) : [...selected, tool]);
			this.persist();
		} else if (matchesKey(data, Key.enter)) this.view = "group";
		this.tui.requestRender();
	}

	private modelOptions(row: SettingRow | undefined): AvailableModel[] {
		if (row?.id !== "reviewer.model") return this.models;
		return [{ value: "", label: "跟随主 agent", description: `thinking: ${this.reviewerThinkingLevels.join(", ")}`, thinkingLevels: this.reviewerThinkingLevels }, ...this.models];
	}

	private toolsForTarget(): string[] {
		return this.toolsTarget === "reviewer" ? REVIEWER_TOOLS : WORKER_TOOLS;
	}

	private selectedTools(): string[] {
		return this.toolsTarget === "reviewer" ? [...(this.config.reviewer.tools ?? [])] : [...(this.config.levels[this.toolsTarget].tools ?? [])];
	}

	private setSelectedTools(tools: string[]): void {
		if (this.toolsTarget === "reviewer") this.config.reviewer.tools = tools.filter((tool) => REVIEWER_TOOLS.includes(tool));
		else this.config.levels[this.toolsTarget].tools = tools;
	}

	private thinkingValues(id: string): string[] {
		if (id === "reviewer.thinkingLevel") {
			const model = this.models.find((item) => item.value === this.config.reviewer.model);
			const levels = model?.thinkingLevels.length ? model.thinkingLevels : this.reviewerThinkingLevels.length ? this.reviewerThinkingLevels : ["off"];
			return this.config.reviewer.model ? levels : [FOLLOW_MAIN, ...levels];
		}
		const [level] = id.split(".") as [ClusterLevel];
		const model = this.models.find((item) => item.value === this.config.levels[level]?.model);
		return model?.thinkingLevels.length ? model.thinkingLevels : THINKING_LEVELS;
	}

	private cycleThinking(id: string, direction: CycleDirection): void {
		const values = this.thinkingValues(id);
		const current = this.value(id);
		const next = cycleOption(values, current, direction) ?? "off";
		if (id === "reviewer.thinkingLevel") this.config.reviewer.thinkingLevel = next === FOLLOW_MAIN ? undefined : next as ClusterConfig["reviewer"]["thinkingLevel"];
		else {
			const [level] = id.split(".") as [ClusterLevel];
			this.config.levels[level].thinkingLevel = next as ClusterConfig["levels"][ClusterLevel]["thinkingLevel"];
		}
		this.persist();
	}

	private normalizeThinking(id: string): void {
		const values = this.thinkingValues(id);
		if (values.includes(this.value(id))) return;
		const value = values[0] ?? "off";
		if (id === "reviewer.thinkingLevel") this.config.reviewer.thinkingLevel = value === FOLLOW_MAIN ? undefined : value as ClusterConfig["reviewer"]["thinkingLevel"];
		else {
			const [level] = id.split(".") as [ClusterLevel];
			this.config.levels[level].thinkingLevel = value as ClusterConfig["levels"][ClusterLevel]["thinkingLevel"];
		}
	}

	private numberOptions(id: string): number[] {
		if (id === "maxConcurrency") return [1, 2, 4, 8, 16];
		if (id === "maxTasks") return [1, 4, 8, 16, 32];
		if (id === "maxRetriesPerLevel") return [0, 1, 2, 3];
		if (id === "learning.taskTypeUpgradeThreshold") return [1, 2, 3, 4, 5, 10];
		if (id === "learning.historyRetentionDays") return [1, 7, 14, 30, 60, 90, 180, 365];
		return [1_000, 5_000, 10_000, 30_000, 60_000, 120_000, 300_000, 600_000, 1_200_000, 1_800_000, 3_600_000, 10_800_000];
	}

	private rawNumberValue(id: string): number {
		if (id === "maxConcurrency") return this.config.maxConcurrency;
		if (id === "maxTasks") return this.config.maxTasks;
		if (id === "maxRetriesPerLevel") return this.config.maxRetriesPerLevel;
		if (id === "learning.taskTypeUpgradeThreshold") return this.config.learning.taskTypeUpgradeThreshold;
		if (id === "learning.historyRetentionDays") return this.config.learning.historyRetentionDays;
		if (id === "reviewer.timeoutMs") return this.config.reviewer.timeoutMs ?? 180_000;
		const [level] = id.split(".") as [ClusterLevel];
		return this.config.levels[level].timeoutMs ?? 900_000;
	}

	private cycleBoolean(id: string, direction: CycleDirection): void {
		if (id !== "learning.enabled") return;
		this.config.learning.enabled = cycleOption([false, true], this.config.learning.enabled, direction) ?? this.config.learning.enabled;
		this.persist();
	}

	private async clearLearningEvidence(): Promise<void> {
		this.actionPending = true;
		this.error = "";
		this.message = "";
		this.tui.requestRender();
		try {
			const result = await this.callbacks.onClearLearningEvidence();
			this.message = result === "cleared" ? "已清除全部全局学习证据" : result === "empty" ? "当前没有全局学习证据" : "已取消清除全局学习证据";
		} catch (error) {
			this.error = error instanceof Error ? error.message : String(error);
		} finally {
			this.actionPending = false;
			this.tui.requestRender();
		}
	}

	private cycleNumber(id: string, direction: CycleDirection): void {
		const current = this.rawNumberValue(id);
		const options = this.numberOptions(id);
		this.setNumber(id, cycleNumberOption(options, current, direction) ?? current);
		this.persist();
	}

	private setNumber(id: string, value: number): void {
		if (id === "maxConcurrency") this.config.maxConcurrency = value;
		else if (id === "maxTasks") this.config.maxTasks = value;
		else if (id === "maxRetriesPerLevel") this.config.maxRetriesPerLevel = value;
		else if (id === "learning.taskTypeUpgradeThreshold") this.config.learning.taskTypeUpgradeThreshold = value;
		else if (id === "learning.historyRetentionDays") this.config.learning.historyRetentionDays = value;
		else if (id === "reviewer.timeoutMs") this.config.reviewer.timeoutMs = value;
		else {
			const [level] = id.split(".") as [ClusterLevel];
			this.config.levels[level].timeoutMs = value;
		}
	}

	private formatDuration(value: number): string {
		let seconds = Math.max(1, Math.round(value / 1_000));
		const hours = Math.floor(seconds / 3_600);
		seconds %= 3_600;
		const minutes = Math.floor(seconds / 60);
		seconds %= 60;
		return [hours ? `${hours}h` : "", minutes ? `${minutes}m` : "", seconds ? `${seconds}s` : ""].filter(Boolean).join(" ");
	}

	private modelValue(id: string): string {
		return id === "reviewer.model" ? this.config.reviewer.model ?? "" : this.value(id);
	}

	private value(id: string): string {
		if (id === "reviewer.model") return this.config.reviewer.model ?? FOLLOW_MAIN;
		if (id === "reviewer.thinkingLevel") return this.config.reviewer.thinkingLevel ?? FOLLOW_MAIN;
		if (id === "reviewer.tools") return (this.config.reviewer.tools ?? []).join(", ");
		if (id === "maxConcurrency") return String(this.config.maxConcurrency);
		if (id === "maxTasks") return String(this.config.maxTasks);
		if (id === "maxRetriesPerLevel") return String(this.config.maxRetriesPerLevel);
		if (id === "learning.enabled") return this.config.learning.enabled ? "开启" : "关闭";
		if (id === "learning.taskTypeUpgradeThreshold") return String(this.config.learning.taskTypeUpgradeThreshold);
		if (id === "learning.historyRetentionDays") return `${this.config.learning.historyRetentionDays} 天`;
		if (id === "learning.clearEvidence") return this.actionPending ? "清除中…" : "Enter 清除";
		if (id === "reviewer.timeoutMs") return this.formatDuration(this.config.reviewer.timeoutMs ?? 180_000);
		const [level, field] = id.split(".") as [ClusterLevel, "model" | "thinkingLevel" | "tools" | "timeoutMs"];
		if (field === "tools") return (this.config.levels[level].tools ?? []).join(", ");
		if (field === "timeoutMs") return this.formatDuration(this.config.levels[level].timeoutMs ?? 900_000);
		return String(this.config.levels[level][field] ?? "");
	}

	private persist(): void {
		const snapshot = JSON.parse(JSON.stringify(this.config)) as ClusterConfig;
		this.persistQueue = this.persistQueue.then(() => this.callbacks.onSave(snapshot)).catch((error) => {
			this.error = error instanceof Error ? error.message : String(error);
			this.tui.requestRender();
		});
	}

	private mainValue(group: Group): string {
		if (group === "cluster") return `学习${this.config.learning.enabled ? "开启" : "关闭"} · Enter 进入`;
		if (group === "reviewer") return this.config.reviewer.model ?? FOLLOW_MAIN;
		return this.config.levels[group].model;
	}

	private renderMain(width: number): string[] {
		const lines = [this.theme.fg("muted", "全局配置 · ~/.pi/agent/subagent-cluster.json"), this.theme.fg("border", "─".repeat(width))];
		const labelWidth = Math.max(...this.mainRows.map((row) => row.label.length));
		for (let index = 0; index < this.mainRows.length; index++) {
			const row = this.mainRows[index];
			const selected = index === this.selectedIndex;
			const prefix = selected ? this.theme.fg("accent", "▸ ") : "  ";
			const label = row.label.padEnd(labelWidth, " ");
			lines.push(truncateToWidth(`${prefix}${selected ? this.theme.fg("accent", label) : label}  ${this.theme.fg("muted", this.mainValue(row.group))}`, width, "", false));
			if (selected) lines.push(this.theme.fg("dim", `    ${row.description}`));
		}
		lines.push(this.theme.fg("border", "─".repeat(width)), this.theme.fg("dim", "↑/↓ 选择 · Enter 进入二级菜单 · Esc 返回"));
		return lines;
	}

	private renderGroup(width: number): string[] {
		const group = this.mainRows.find((row) => row.group === this.selectedGroup);
		const rows = this.groupRows(this.selectedGroup);
		const labelWidth = Math.max(...rows.map((row) => row.label.length));
		const lines = [this.theme.fg("accent", this.theme.bold(`${group?.label ?? this.selectedGroup} Settings`)), this.theme.fg("dim", group?.description ?? ""), this.theme.fg("border", "─".repeat(width))];
		for (let index = 0; index < rows.length; index++) {
			const row = rows[index];
			const selected = index === this.selectedIndex;
			const prefix = selected ? this.theme.fg("accent", "▸ ") : "  ";
			const label = row.label.padEnd(labelWidth, " ");
			lines.push(truncateToWidth(`${prefix}${selected ? this.theme.fg("accent", label) : label}  ${this.theme.fg("muted", this.value(row.id))}`, width, "", false));
			if (selected) {
				const hint = row.kind === "thinking"
					? `←/→ 切换 · 可选：${this.thinkingValues(row.id).join(", ")}`
					: row.kind === "number" || row.kind === "boolean"
						? "←/→ 切换"
						: row.kind === "action"
							? "Enter 执行"
							: "Enter 打开";
				lines.push(this.theme.fg("dim", `    ${row.description} · ${hint}`));
			}
		}
		if (this.error) lines.push(this.theme.fg("error", this.error));
		if (this.message) lines.push(this.theme.fg("success", this.message));
		lines.push(this.theme.fg("border", "─".repeat(width)), this.theme.fg("dim", "↑/↓ 选择 · ←/→ 调整 · Enter 打开或执行 · Esc 返回 · 每次修改自动保存"));
		return lines;
	}

	private renderModels(width: number): string[] {
		const row = this.groupRows(this.selectedGroup)[this.selectedIndex];
		const options = this.modelOptions(row);
		const current = this.modelValue(row?.id ?? "");
		const lines = [this.theme.fg("accent", this.theme.bold(`${row?.label ?? "Model"} · 选择可用模型`)), this.theme.fg("border", "─".repeat(width))];
		for (let index = 0; index < options.length; index++) {
			const model = options[index];
			const selected = index === this.subIndex;
			const marker = selected ? this.theme.fg("accent", "▸ ") : "  ";
			const currentMark = model.value === current ? this.theme.fg("success", " ✓") : "";
			lines.push(truncateToWidth(`${marker}${model.label}${currentMark}  ${this.theme.fg("dim", model.description)}`, width, "", false));
		}
		lines.push(this.theme.fg("border", "─".repeat(width)), this.theme.fg("dim", "↑/↓ 选择 · Enter 确认 · Esc 返回"));
		return lines;
	}

	private renderTools(width: number): string[] {
		const tools = this.toolsForTarget();
		const selectedTools = this.selectedTools();
		const title = this.toolsTarget === "reviewer" ? "REVIEWER tools · 只读多选" : `${this.toolsTarget.toUpperCase()} tools · 多选工具`;
		const lines = [this.theme.fg("accent", this.theme.bold(title)), this.theme.fg("border", "─".repeat(width))];
		for (let index = 0; index < tools.length; index++) {
			const tool = tools[index];
			const selected = index === this.subIndex;
			const checked = selectedTools.includes(tool) ? this.theme.fg("success", "[x]") : this.theme.fg("dim", "[ ]");
			lines.push(truncateToWidth(`${selected ? this.theme.fg("accent", "▸ ") : "  "}${checked} ${tool}`, width, "", false));
		}
		lines.push(this.theme.fg("border", "─".repeat(width)), this.theme.fg("dim", "↑/↓ 选择 · Space 开关 · Enter 返回 · 每次修改自动保存"));
		return lines;
	}

	invalidate(): void {}
}