// =============================================================================
// config.ts — soly config loader (per-project + global)
// =============================================================================
//
// Per-project: `.agents/soly.json` (version-controlled, repo-specific).
// Global:     `~/.agents/soly.json` (per-user, applies to all projects).
//
// Lookup order: per-project overrides global overrides defaults. Missing
// files are silently ignored (defaults apply). Malformed JSON returns a
// "fallback to defaults" warning via the return value's `warnings` array.
//
// Schema versioning: if the file's `version` doesn't match SOLY_CONFIG_VERSION,
// we still try to merge what we can and add a warning.
// =============================================================================

import * as fs from "node:fs";
import * as os from "node:os";
import * as path from "node:path";

export const SOLY_CONFIG_VERSION = 1 as const;

/** Defaults — also the "schema" (all keys optional, merged with user overrides). */
export interface SolyConfig {
	version: typeof SOLY_CONFIG_VERSION;
	iteration: {
		/** Auto-prune iteration files older than N days on session_start. 0 = keep forever. */
		retentionDays: number;
		/** Include RESEARCH.md sections in the per-iteration context bundle. */
		includeResearch: boolean;
		/** Include Anti-Patterns table from .continue-here.md in the bundle. */
		includeAntiPatterns: boolean;
	};
	agent: {
		/** When ask_pro tool is available, prefer it over soly_ask_user in discuss flow. */
		preferAskPro: boolean;
		/** When soly pause is invoked, also auto-save HANDOFF.json (currently always true; knob for future). */
		autoCheckpointOnPause: boolean;
		/** Show the soft "non-trivial / research" nudge as a chat box. Default off
		 *  (it was noisy). The system-prompt nudge guides the LLM regardless. */
		nudgeNotify: boolean;
		/** Inject per-turn affordance hints (examples → html_artifact, options →
		 *  decision_deck, …) when the prompt mentions those. Default on. */
		toolHints: boolean;
		/** Before non-trivial coding, make the LLM ask the user the decisions
		 *  only they can make, instead of coding on assumptions. Levels:
		 *    "scope" — batch the substantive questions (placement, pattern,
		 *              scope, interface) via ask_pro, then wait. (default)
		 *    "ask"   — lighter: one "ready to implement, or discuss?" question.
		 *    "off"   — no gate.
		 *  Booleans accepted for back-compat: true = "scope", false = "off". */
		confirmBeforeCode: boolean | "off" | "ask" | "scope";
	};
	display: {
		/** Always show the recommended (⭐) option as the first row. */
		defaultRecommendedFirst: boolean;
		/** Cap on how many phases appear in /soly status / soly status. */
		maxPhasesInStatus: number;
		/** Cap on how many decisions appear in soly log default. */
		maxDecisionsInLog: number;
	};
	paths: {
		/** Globs to exclude from code-map / project scans. */
		excludeGlobs: string[];
	};
	hotReload: {
		/** Hot-reload poll interval (ms). Default 2000. */
		pollMs: number;
		/** Show a notify when rules change. */
		notifyOnRuleChange: boolean;
	};
	editor: {
		/** $EDITOR command for opening files (e.g. "code", "vim", "cursor"). */
		command: string;
	};
	chrome: {
		/** Install soly's status chrome (top bar + custom footer + spinner). */
		enabled: boolean;
		/** Use ASCII fallbacks instead of Nerd-Font glyphs. */
		ascii: boolean;
		/** Working-spinner animation frames (rendered verbatim by pi). */
		spinnerFrames: string[];
		/** Working-spinner frame interval in ms. */
		spinnerIntervalMs: number;
		/** Show live telemetry (elapsed · ↑↓ tokens · tok/s) in the working line. */
		telemetry: boolean;
		/** Hex gradient stops for the welcome banner (empty → accent color). */
		bannerColors: string[];
	};
	verify: {
		/** Max self-review passes before the loop stops on its own. */
		maxIterations: number;
		/** Strip prior review iterations from context each pass ("fresh eyes"). */
		freshContext: boolean;
		/** Review prompt re-injected each pass. */
		prompt: string;
		/** Regex (case-insensitive) signaling "nothing left to fix" → exit. */
		exitPatterns: string[];
		/** Regex signaling issues were fixed → keep looping despite an exit phrase. */
		issuesFixedPatterns: string[];
	};
	artifacts: {
		/** Open generated HTML artifacts in the browser automatically. */
		open: boolean;
		/** Output directory. Empty → OS temp dir (pi-soly-artifacts/). Accepts an
		 *  absolute path, ~, or a path relative to the project cwd. */
		dir: string;
		/** Serve artifacts from a per-session HTTP server with a live gallery
		 *  (one stable localhost URL). When false, just open the .html file. */
		server: boolean;
		/** Path to a CSS file overriding the artifact theme. Empty → built-in.
		 *  Resolved like `dir`; also auto-detected at `.agents/artifact-theme.css`. */
		theme: string;
		/** Prune session artifact dirs older than N days on session start.
		 *  0 = keep forever. */
		retentionDays: number;
	};
	plan: {
		/** Optional branch prefix prepended when the user runs `soly new <slug>`
		 *  without an explicit `<prefix>/<slug>` form. Common values:
		 *    "feature"   → branches like `feature/statistic-preparation`
		 *    "fix"       → branches like `fix/login-redirect`
		 *    "" (default)→ no prefix; branch = slug verbatim.
		 *  Per-project only (set in `.agents/soly.json`). User-supplied
		 *  `<prefix>/<slug>` always wins over this default.
		 *  Plan dir is always `.agents/plans/<prefix>-<slug>` (flattened)
		 *  so the on-disk layout stays one-deep. */
		defaultBranchPrefix: string;
	};
}

export const DEFAULT_CONFIG: SolyConfig = {
	version: SOLY_CONFIG_VERSION,
	iteration: {
		retentionDays: 0, // 0 = keep forever
		includeResearch: true,
		includeAntiPatterns: true,
	},
	agent: {
		preferAskPro: true,
		autoCheckpointOnPause: true,
		nudgeNotify: false,
		toolHints: true,
		confirmBeforeCode: "scope",
	},
	display: {
		defaultRecommendedFirst: true,
		maxPhasesInStatus: 20,
		maxDecisionsInLog: 20,
	},
	paths: {
		excludeGlobs: ["**/node_modules/**", "**/dist/**", "**/.git/**", "**/build/**", "**/.next/**", "**/.nuxt/**", "**/coverage/**"],
	},
	hotReload: {
		pollMs: 2000,
		notifyOnRuleChange: true,
	},
	editor: {
		command: "code",
	},
	chrome: {
		enabled: true,
		ascii: false,
		spinnerFrames: [
			"⠁", "⠉", "⠙", "⠹", "⠽", "⠿", "⠾", "⠼", "⠶", "⠦", "⠆", "⠂",
			"◴", "◷", "◶", "◵",
			"⠁", "⠉", "⠙", "⠹", "⠽", "⠿", "⠾", "⠼", "⠶", "⠦", "⠆", "⠂",
		],
		spinnerIntervalMs: 150,
		telemetry: true,
		bannerColors: [], // empty → gradient derived from the theme accent
	},
	verify: {
		maxIterations: 7,
		freshContext: false,
		prompt:
			"Review the work from this session with fresh eyes. Re-read any relevant plan, " +
			"spec, or PRD first. Look for bugs, missed edge cases, missing error handling, and " +
			"inconsistencies with the project rules. If you find problems, fix them, then end your " +
			'reply with: "Fixed N issue(s). Ready for another review." If you find nothing, end with ' +
			'exactly: "No issues found."',
		exitPatterns: ["no issues found", "no further issues", "nothing to fix"],
		issuesFixedPatterns: ["fixed \\d+ issue", "ready for another review", "issues? fixed"],
	},
	artifacts: {
		open: true,
		dir: "",
		server: true,
		theme: "",
		retentionDays: 7,
	},
	plan: {
		defaultBranchPrefix: "", // "" = no prefix; branch = slug verbatim
	},
};

/** Raw parsed shape from a config.json — could be partial, could have wrong types. */
type RawConfig = Partial<SolyConfig> & { version?: number };

function readJsonIfExists(path: string): RawConfig | null {
	try {
		if (!fs.existsSync(path)) return null;
		const raw = fs.readFileSync(path, "utf-8");
		return JSON.parse(raw) as RawConfig;
	} catch {
		return null;
	}
}

export interface LoadConfigResult {
	config: SolyConfig;
	warnings: string[];
	sources: { global: string | null; project: string | null };
}

/** Deep-merge `over` into `base`, with the same shape. Used to apply user
 *  overrides on top of defaults. Only known keys are merged. */
function deepMerge(base: SolyConfig, over: RawConfig): SolyConfig {
	const merged: SolyConfig = JSON.parse(JSON.stringify(base));
	if (over.iteration) {
		if (typeof over.iteration.retentionDays === "number")
			merged.iteration.retentionDays = over.iteration.retentionDays;
		if (typeof over.iteration.includeResearch === "boolean")
			merged.iteration.includeResearch = over.iteration.includeResearch;
		if (typeof over.iteration.includeAntiPatterns === "boolean")
			merged.iteration.includeAntiPatterns = over.iteration.includeAntiPatterns;
	}
	if (over.agent) {
		if (typeof over.agent.preferAskPro === "boolean")
			merged.agent.preferAskPro = over.agent.preferAskPro;
		if (typeof over.agent.autoCheckpointOnPause === "boolean")
			merged.agent.autoCheckpointOnPause = over.agent.autoCheckpointOnPause;
		if (typeof over.agent.nudgeNotify === "boolean")
			merged.agent.nudgeNotify = over.agent.nudgeNotify;
		if (typeof over.agent.toolHints === "boolean")
			merged.agent.toolHints = over.agent.toolHints;
		if (
			typeof over.agent.confirmBeforeCode === "boolean" ||
			over.agent.confirmBeforeCode === "off" ||
			over.agent.confirmBeforeCode === "ask" ||
			over.agent.confirmBeforeCode === "scope"
		)
			merged.agent.confirmBeforeCode = over.agent.confirmBeforeCode;
	}
	if (over.display) {
		if (typeof over.display.defaultRecommendedFirst === "boolean")
			merged.display.defaultRecommendedFirst = over.display.defaultRecommendedFirst;
		if (typeof over.display.maxPhasesInStatus === "number")
			merged.display.maxPhasesInStatus = over.display.maxPhasesInStatus;
		if (typeof over.display.maxDecisionsInLog === "number")
			merged.display.maxDecisionsInLog = over.display.maxDecisionsInLog;
	}
	if (over.paths && Array.isArray(over.paths.excludeGlobs)) {
		merged.paths.excludeGlobs = over.paths.excludeGlobs.filter((g) => typeof g === "string");
	}
	if (over.hotReload) {
		if (typeof over.hotReload.pollMs === "number")
			merged.hotReload.pollMs = over.hotReload.pollMs;
		if (typeof over.hotReload.notifyOnRuleChange === "boolean")
			merged.hotReload.notifyOnRuleChange = over.hotReload.notifyOnRuleChange;
	}
	if (over.editor && typeof over.editor.command === "string") {
		merged.editor.command = over.editor.command;
	}
	if (over.plan && typeof over.plan.defaultBranchPrefix === "string") {
		// Sanitize: lowercase, then allow only kebab-case chars (no
		// slashes/dots/spaces). Empty string is allowed and means
		// "no prefix". We do NOT warn on slash/uppercase — the user
		// probably meant a different prefix shape; silently normalizing
		// keeps configs from being rejected for cosmetic reasons.
		const lowercased = over.plan.defaultBranchPrefix.toLowerCase();
		const sanitized = lowercased.replace(/[^a-z0-9-]/g, "");
		const collapsed = sanitized.replace(/-+/g, "-").replace(/^-|-$/g, "");
		merged.plan.defaultBranchPrefix = collapsed;
	}
	if (over.chrome) {
		if (typeof over.chrome.enabled === "boolean") merged.chrome.enabled = over.chrome.enabled;
		if (typeof over.chrome.ascii === "boolean") merged.chrome.ascii = over.chrome.ascii;
		if (Array.isArray(over.chrome.spinnerFrames)) {
			const frames = over.chrome.spinnerFrames.filter((f) => typeof f === "string");
			if (frames.length > 0) merged.chrome.spinnerFrames = frames;
		}
		if (typeof over.chrome.spinnerIntervalMs === "number" && over.chrome.spinnerIntervalMs > 0)
			merged.chrome.spinnerIntervalMs = over.chrome.spinnerIntervalMs;
		if (typeof over.chrome.telemetry === "boolean") merged.chrome.telemetry = over.chrome.telemetry;
		if (Array.isArray(over.chrome.bannerColors)) {
			merged.chrome.bannerColors = over.chrome.bannerColors.filter((c) => typeof c === "string");
		}
	}
	if (over.verify) {
		if (typeof over.verify.maxIterations === "number" && over.verify.maxIterations > 0)
			merged.verify.maxIterations = over.verify.maxIterations;
		if (typeof over.verify.freshContext === "boolean") merged.verify.freshContext = over.verify.freshContext;
		if (typeof over.verify.prompt === "string" && over.verify.prompt.trim()) merged.verify.prompt = over.verify.prompt;
		if (Array.isArray(over.verify.exitPatterns))
			merged.verify.exitPatterns = over.verify.exitPatterns.filter((p) => typeof p === "string");
		if (Array.isArray(over.verify.issuesFixedPatterns))
			merged.verify.issuesFixedPatterns = over.verify.issuesFixedPatterns.filter((p) => typeof p === "string");
	}
	if (over.artifacts) {
		if (typeof over.artifacts.open === "boolean") merged.artifacts.open = over.artifacts.open;
		if (typeof over.artifacts.dir === "string") merged.artifacts.dir = over.artifacts.dir;
		if (typeof over.artifacts.server === "boolean") merged.artifacts.server = over.artifacts.server;
		if (typeof over.artifacts.theme === "string") merged.artifacts.theme = over.artifacts.theme;
		if (typeof over.artifacts.retentionDays === "number" && over.artifacts.retentionDays >= 0)
			merged.artifacts.retentionDays = over.artifacts.retentionDays;
	}
	return merged;
}

/** Load soly config. Per-project overrides global overrides defaults.
 *  Returns merged config + warnings about any issues.
 *  Optional `homeDir` overrides `os.homedir()` — used by tests; production
 *  callers leave it unset. */
export function loadConfig(cwd: string, homeDir?: string): LoadConfigResult {
	const warnings: string[] = [];
	const sources = { global: null as string | null, project: null as string | null };

	const home = homeDir ?? os.homedir();
	const globalPath = path.join(home, ".agents", "soly.json");
	const globalRaw = readJsonIfExists(globalPath);
	if (globalRaw) {
		sources.global = globalPath;
		if (typeof globalRaw.version === "number" && globalRaw.version !== SOLY_CONFIG_VERSION) {
			warnings.push(
				`global config at ${globalPath} has version ${globalRaw.version}, expected ${SOLY_CONFIG_VERSION} — using defaults for unknown fields`,
			);
		}
	}
	const projectPath = path.join(cwd, ".agents", "soly.json");
	const projectRaw = readJsonIfExists(projectPath);
	if (projectRaw) {
		sources.project = projectPath;
		if (typeof projectRaw.version === "number" && projectRaw.version !== SOLY_CONFIG_VERSION) {
			warnings.push(
				`project config at ${projectPath} has version ${projectRaw.version}, expected ${SOLY_CONFIG_VERSION} — using defaults for unknown fields`,
			);
		}
	}

	let config = deepMerge(DEFAULT_CONFIG, globalRaw ?? {});
	config = deepMerge(config, projectRaw ?? {});
	return { config, warnings, sources };
}

// ---------------------------------------------------------------------------
// Iteration retention
// ---------------------------------------------------------------------------

/** Delete iteration files older than `retentionDays` (0 = no deletion). */
export function pruneOldIterations(solyDir: string, retentionDays: number): {
	pruned: number;
	kept: number;
} {
	if (retentionDays <= 0) return { pruned: 0, kept: -1 };
	const iterDir = path.join(solyDir, "iterations");
	if (!fs.existsSync(iterDir)) return { pruned: 0, kept: 0 };

	const now = Date.now();
	const cutoffMs = retentionDays * 24 * 60 * 60 * 1000;
	let pruned = 0;
	let kept = 0;
	for (const entry of fs.readdirSync(iterDir)) {
		const full = path.join(iterDir, entry);
		try {
			const stat = fs.statSync(full);
			if (stat.isFile() && now - stat.mtimeMs > cutoffMs) {
				fs.unlinkSync(full);
				pruned++;
			} else {
				kept++;
			}
		} catch {
			// skip unreadable
		}
	}
	return { pruned, kept };
}