import type { DirectoryArtifactModel, FileEntry } from "./directory-model.js";
import { PROJECT_MAP_PROTOCOL_LINES } from "./directory-model.js";

export interface PackageMapData {
	path: string;
	role: string;
	files: FileEntry[];
	arch: string;
	dirty?: string;
}

export function renderPackageMap(data: PackageMapData): string {
	const model = convertPackageMapToModel(data);
	return renderDirectoryMap(model);
}

export function parsePackageMap(markdown: string): PackageMapData {
	const model = parseDirectoryMap(markdown);
	return convertModelToPackageMap(model);
}

function convertPackageMapToModel(
	data: PackageMapData,
): DirectoryArtifactModel {
	return {
		dir: data.path,
		role: data.role,
		files: data.files,
		arch: data.arch,
		dirty: data.dirty,
		isRoot: data.path === ".",
		parent: undefined,
		children: [],
		tags: [],
		symbols: [],
		workflows: [],
	};
}

function convertModelToPackageMap(
	model: DirectoryArtifactModel,
): PackageMapData {
	return {
		path: model.dir,
		role: model.role,
		files: model.files,
		arch: model.arch,
		dirty: model.dirty,
	};
}

export function renderDirectoryMap(model: DirectoryArtifactModel): string {
	const lines: string[] = [];
	lines.push(`# ${model.dir}`);
	lines.push(`dir: ${model.dir}`);
	lines.push("");
	lines.push(`index: ${model.dir}/.pi-map.index.md`);
	lines.push("");

	if (model.isRoot) {
		lines.push(...PROJECT_MAP_PROTOCOL_LINES);
		lines.push("");
	}

	lines.push(`## role`);
	lines.push(model.role);

	lines.push(`## files`);
	for (const file of model.files) {
		const exp =
			file.exports.length > 0 ? `exp: ${file.exports.join(", ")}` : "";
		const dep = file.deps.length > 0 ? `dep: ${file.deps.join(", ")}` : "";
		const parts = [`- ${file.name} | ${file.purpose}`];
		if (exp) parts.push(exp);
		if (dep) parts.push(dep);
		lines.push(parts.join(" | "));
	}

	lines.push(`## arch`);
	lines.push(model.arch);

	// Slice 2: tags, symbols, workflows — scaffold empty sections for now
	lines.push(`## tags`);
	if (model.tags.length > 0) {
		lines.push(model.tags.join(", "));
	} else {
		lines.push("-");
	}

	lines.push(`## symbols`);
	if (model.symbols.length > 0) {
		for (const sym of model.symbols) {
			lines.push(`- ${sym}`);
		}
	} else {
		lines.push("-");
	}

	lines.push(`## workflows`);
	if (model.workflows.length > 0) {
		for (const wf of model.workflows) {
			lines.push(`- ${wf.task}`);
			if (wf.read && wf.read.length > 0) {
				lines.push(`  read: ${wf.read.join(", ")}`);
			}
			if (wf.index && wf.index.length > 0) {
				lines.push(`  index: ${wf.index.join(", ")}`);
			}
			if (wf.map && wf.map.length > 0) {
				lines.push(`  map: ${wf.map.join(", ")}`);
			}
			if (wf.files && wf.files.length > 0) {
				lines.push(`  files: ${wf.files.join(", ")}`);
			}
		}
	} else {
		lines.push("-");
	}

	lines.push(`## dirty`);
	lines.push(model.dirty || "-");
	return `${lines.join("\n")}\n`;
}

export function parseDirectoryMap(markdown: string): DirectoryArtifactModel {
	const lines = markdown.split("\n").map((l) => l.trimEnd());
	const result: DirectoryArtifactModel = {
		dir: "",
		role: "",
		files: [],
		arch: "",
		dirty: "-",
		isRoot: false,
		parent: undefined,
		children: [],
		tags: [],
		symbols: [],
		workflows: [],
	};

	let section:
		| "none"
		| "role"
		| "files"
		| "arch"
		| "tags"
		| "symbols"
		| "workflows"
		| "dirty" = "none";

	for (const line of lines) {
		if (line.startsWith("# ")) {
			result.dir = line.slice(2).trim();
			result.isRoot = result.dir === ".";
			continue;
		}
		if (line.startsWith("dir: ")) {
			result.dir = line.slice(5).trim();
			result.isRoot = result.dir === ".";
			continue;
		}
		if (line === "## role") {
			section = "role";
			continue;
		}
		if (line === "## files") {
			section = "files";
			continue;
		}
		if (line === "## arch") {
			section = "arch";
			continue;
		}
		if (line === "## tags") {
			section = "tags";
			continue;
		}
		if (line === "## symbols") {
			section = "symbols";
			continue;
		}
		if (line === "## workflows") {
			section = "workflows";
			continue;
		}
		if (line === "## dirty") {
			section = "dirty";
			continue;
		}
		if (line === "") continue;

		switch (section) {
			case "role":
				result.role = line;
				break;
			case "files": {
				if (!line.startsWith("- ")) continue;
				const entry = parseFileLine(line);
				if (entry) result.files.push(entry);
				break;
			}
			case "arch":
				result.arch = result.arch ? `${result.arch}\n${line}` : line;
				break;
			case "tags":
				if (line !== "-") {
					result.tags.push(
						...line
							.split(",")
							.map((s) => s.trim())
							.filter(Boolean),
					);
				}
				break;
			case "symbols":
				if (line !== "-" && line.startsWith("- ")) {
					result.symbols.push(line.slice(2).trim());
				}
				break;
			case "workflows": {
				if (line !== "-" && line.startsWith("- ")) {
					const task = line.slice(2).trim();
					result.workflows.push({ task });
				} else if (line.startsWith("  read: ") && result.workflows.length > 0) {
					const reads = line
						.slice(8)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.read = reads;
				} else if (
					line.startsWith("  index: ") &&
					result.workflows.length > 0
				) {
					const indices = line
						.slice(9)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.index = indices;
				} else if (line.startsWith("  map: ") && result.workflows.length > 0) {
					const maps = line
						.slice(7)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.map = maps;
				} else if (
					line.startsWith("  files: ") &&
					result.workflows.length > 0
				) {
					const files = line
						.slice(9)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.files = files;
				}
				break;
			}
			case "dirty":
				result.dirty = line === "-" ? undefined : line;
				break;
		}
	}

	return result;
}

function splitTopLevel(str: string, delimiter: string): string[] {
	const result: string[] = [];
	let current = "";
	let depthParen = 0;
	let depthBracket = 0;
	let depthBrace = 0;
	let depthAngle = 0;
	let inString: '"' | "'" | null = null;

	for (let i = 0; i < str.length; i++) {
		const ch = str[i];
		const prev = str[i - 1];
		const next = str[i + 1];

		if (inString) {
			if (ch === inString && prev !== "\\") {
				inString = null;
			}
			current += ch;
			continue;
		}

		if (ch === '"' || ch === "'") {
			const isWordApostrophe =
				ch === "'" &&
				/[A-Za-z0-9_$]/.test(prev ?? "") &&
				/[A-Za-z0-9_$]/.test(next ?? "");
			if (isWordApostrophe) {
				current += ch;
				continue;
			}
			inString = ch;
			current += ch;
			continue;
		}

		if (ch === "(") depthParen++;
		if (ch === ")") depthParen = Math.max(0, depthParen - 1);
		if (ch === "[") depthBracket++;
		if (ch === "]") depthBracket = Math.max(0, depthBracket - 1);
		if (ch === "{") depthBrace++;
		if (ch === "}") depthBrace = Math.max(0, depthBrace - 1);
		if (ch === "<") depthAngle++;
		if (ch === ">") depthAngle = Math.max(0, depthAngle - 1);

		if (
			delimiter.length === 1 &&
			ch === delimiter &&
			depthParen === 0 &&
			depthBracket === 0 &&
			depthBrace === 0 &&
			depthAngle === 0
		) {
			result.push(current.trim());
			current = "";
			continue;
		}

		if (
			delimiter.length > 1 &&
			str.startsWith(delimiter, i) &&
			depthParen === 0 &&
			depthBracket === 0 &&
			depthBrace === 0 &&
			depthAngle === 0
		) {
			result.push(current.trim());
			current = "";
			i += delimiter.length - 1;
			continue;
		}

		current += ch;
	}

	if (current.trim()) result.push(current.trim());
	return result;
}

function splitRespectingNesting(str: string): string[] {
	return splitTopLevel(str, ",");
}

function splitFieldsRespectingNesting(str: string): string[] {
	const rawParts = splitTopLevel(str, " | ");
	const fields: string[] = [];

	for (const part of rawParts) {
		const trimmed = part.trim();
		if (
			fields.length < 2 ||
			trimmed.startsWith("exp: ") ||
			trimmed.startsWith("dep: ")
		) {
			fields.push(trimmed);
		} else if (fields.length > 0) {
			fields[fields.length - 1] = `${fields[fields.length - 1]} | ${trimmed}`;
		}
	}

	return fields;
}

function parseFileLine(line: string): FileEntry | null {
	// Format: - filename | purpose | exp: ... | dep: ...
	const withoutPrefix = line.slice(2).trim();
	const parts = splitFieldsRespectingNesting(withoutPrefix).map((p) =>
		p.trim(),
	);

	if (parts.length < 2) return null;

	const name = parts[0];
	const purpose = parts[1];
	const exports: string[] = [];
	const deps: string[] = [];

	for (let i = 2; i < parts.length; i++) {
		const part = parts[i];
		if (part.startsWith("exp: ")) {
			exports.push(...splitRespectingNesting(part.slice(5)).filter(Boolean));
		} else if (part.startsWith("dep: ")) {
			deps.push(...splitRespectingNesting(part.slice(5)).filter(Boolean));
		}
	}

	return { name, purpose, exports, deps };
}

export function renderDirectoryIndex(model: DirectoryArtifactModel): string {
	const lines: string[] = [];
	lines.push(`# ${model.dir} (index)`);
	lines.push(`dir: ${model.dir}`);
	lines.push("");

	if (model.isRoot) {
		lines.push(...PROJECT_MAP_PROTOCOL_LINES);
		lines.push("");
	}

	lines.push(`## role`);
	lines.push(model.role);

	lines.push(`## parent`);
	if (model.parent) {
		lines.push(`index: ${model.parent}/.pi-map.index.md`);
		lines.push(`map: ${model.parent}/.pi-map.md`);
	} else {
		lines.push("-");
	}

	lines.push(`## children`);
	if (model.children.length > 0) {
		for (const child of model.children) {
			lines.push(`- ${child}`);
			lines.push(`  index: ${child}/.pi-map.index.md`);
			lines.push(`  map: ${child}/.pi-map.md`);
		}
	} else {
		lines.push("-");
	}

	lines.push(`## files`);
	for (const file of model.files) {
		lines.push(`- ${file.name}`);
	}

	lines.push(`## links`);
	lines.push(`index: ${model.dir}/.pi-map.index.md`);
	lines.push(`map: ${model.dir}/.pi-map.md`);

	lines.push(`## workflows`);
	if (model.workflows.length > 0) {
		for (const wf of model.workflows) {
			lines.push(`- ${wf.task}`);
			if (wf.read && wf.read.length > 0) {
				lines.push(`  read: ${wf.read.join(", ")}`);
			}
			if (wf.index && wf.index.length > 0) {
				lines.push(`  index: ${wf.index.join(", ")}`);
			}
			if (wf.map && wf.map.length > 0) {
				lines.push(`  map: ${wf.map.join(", ")}`);
			}
			if (wf.files && wf.files.length > 0) {
				lines.push(`  files: ${wf.files.join(", ")}`);
			}
		}
	} else {
		lines.push("-");
	}

	lines.push(`## dirty`);
	lines.push(model.dirty || "-");

	return `${lines.join("\n")}\n`;
}

export function parseDirectoryIndex(markdown: string): DirectoryArtifactModel {
	const lines = markdown.split("\n").map((l) => l.trimEnd());
	const result: DirectoryArtifactModel = {
		dir: "",
		role: "",
		files: [],
		arch: "",
		dirty: "-",
		isRoot: false,
		parent: undefined,
		children: [],
		tags: [],
		symbols: [],
		workflows: [],
	};

	let section:
		| "none"
		| "role"
		| "parent"
		| "children"
		| "files"
		| "links"
		| "workflows"
		| "dirty" = "none";

	for (const line of lines) {
		if (line.startsWith("# ")) {
			const title = line.slice(2).trim();
			// Strip " (index)" suffix if present
			result.dir = title.replace(/ \(index\)$/, "");
			result.isRoot = result.dir === ".";
			continue;
		}
		if (line.startsWith("dir: ")) {
			result.dir = line.slice(5).trim();
			result.isRoot = result.dir === ".";
			continue;
		}
		if (line === "## role") {
			section = "role";
			continue;
		}
		if (line === "## parent") {
			section = "parent";
			continue;
		}
		if (line === "## children") {
			section = "children";
			continue;
		}
		if (line === "## files") {
			section = "files";
			continue;
		}
		if (line === "## links") {
			section = "links";
			continue;
		}
		if (line === "## workflows") {
			section = "workflows";
			continue;
		}
		if (line === "## dirty") {
			section = "dirty";
			continue;
		}
		if (line === "") continue;

		switch (section) {
			case "role":
				result.role = line;
				break;
			case "parent":
				if (line !== "-" && line.startsWith("index: ")) {
					result.parent = line.slice(7).trim().replace("/.pi-map.index.md", "");
				}
				break;
			case "children":
				if (line !== "-" && line.startsWith("- ")) {
					const childName = line.slice(2).trim();
					result.children.push(childName);
				}
				break;
			case "files":
				if (line !== "-" && line.startsWith("- ")) {
					result.files.push({
						name: line.slice(2).trim(),
						purpose: "",
						exports: [],
						deps: [],
					});
				}
				break;
			case "links":
				// Parse sibling links; no-op for now
				break;
			case "workflows": {
				if (line !== "-" && line.startsWith("- ")) {
					const task = line.slice(2).trim();
					result.workflows.push({ task });
				} else if (line.startsWith("  read: ") && result.workflows.length > 0) {
					const reads = line
						.slice(8)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.read = reads;
				} else if (
					line.startsWith("  index: ") &&
					result.workflows.length > 0
				) {
					const indices = line
						.slice(9)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.index = indices;
				} else if (line.startsWith("  map: ") && result.workflows.length > 0) {
					const maps = line
						.slice(7)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.map = maps;
				} else if (
					line.startsWith("  files: ") &&
					result.workflows.length > 0
				) {
					const files = line
						.slice(9)
						.trim()
						.split(",")
						.map((s) => s.trim())
						.filter(Boolean);
					const last = result.workflows[result.workflows.length - 1];
					if (last) last.files = files;
				}
				break;
			}
			case "dirty":
				result.dirty = line === "-" ? undefined : line;
				break;
		}
	}

	return result;
}