use clap as _;
use dirs as _;
use libmcp as _;
use std::fs;
use std::io::{self, BufRead, BufReader, Write};
use std::os::unix::fs::PermissionsExt;
use std::path::{Path, PathBuf};
use std::process::{Child, ChildStdin, ChildStdout, Command, Stdio};

use libmcp_testkit::read_json_lines;
use serde as _;
use serde_json::{Value, json};
use thiserror as _;

type TestResult<T = ()> = Result<T, Box<dyn std::error::Error>>;

fn must<T, E: std::fmt::Display, C: std::fmt::Display>(
    result: Result<T, E>,
    context: C,
) -> TestResult<T> {
    result.map_err(|error| io::Error::other(format!("{context}: {error}")).into())
}

fn must_some<T>(value: Option<T>, context: &str) -> TestResult<T> {
    value.ok_or_else(|| io::Error::other(context).into())
}

fn temp_root(name: &str) -> TestResult<PathBuf> {
    let root = std::env::temp_dir().join(format!(
        "phone_opus_{name}_{}_{}",
        std::process::id(),
        must(
            std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH),
            "current time after unix epoch",
        )?
        .as_nanos()
    ));
    must(fs::create_dir_all(&root), "create temp root")?;
    Ok(root)
}

fn binary_path() -> PathBuf {
    PathBuf::from(env!("CARGO_BIN_EXE_phone-opus"))
}

struct McpHarness {
    child: Child,
    stdin: ChildStdin,
    stdout: BufReader<ChildStdout>,
}

impl McpHarness {
    fn spawn(state_home: &Path, extra_env: &[(&str, &str)]) -> TestResult<Self> {
        let mut command = Command::new(binary_path());
        let _ = command
            .arg("mcp")
            .arg("serve")
            .env("XDG_STATE_HOME", state_home)
            .stdin(Stdio::piped())
            .stdout(Stdio::piped())
            .stderr(Stdio::inherit());
        for (key, value) in extra_env {
            let _ = command.env(key, value);
        }
        let mut child = must(command.spawn(), "spawn mcp host")?;
        let stdin = must_some(child.stdin.take(), "host stdin")?;
        let stdout = BufReader::new(must_some(child.stdout.take(), "host stdout")?);
        Ok(Self {
            child,
            stdin,
            stdout,
        })
    }

    fn initialize(&mut self) -> TestResult<Value> {
        self.request(json!({
            "jsonrpc": "2.0",
            "id": 1,
            "method": "initialize",
            "params": {
                "protocolVersion": "2025-11-25",
                "capabilities": {},
                "clientInfo": { "name": "mcp-hardening-test", "version": "0" }
            }
        }))
    }

    fn notify_initialized(&mut self) -> TestResult {
        self.notify(json!({
            "jsonrpc": "2.0",
            "method": "notifications/initialized",
        }))
    }

    fn tools_list(&mut self) -> TestResult<Value> {
        self.request(json!({
            "jsonrpc": "2.0",
            "id": 2,
            "method": "tools/list",
            "params": {},
        }))
    }

    fn call_tool(&mut self, id: u64, name: &str, arguments: Value) -> TestResult<Value> {
        self.request(json!({
            "jsonrpc": "2.0",
            "id": id,
            "method": "tools/call",
            "params": {
                "name": name,
                "arguments": arguments,
            }
        }))
    }

    fn request(&mut self, message: Value) -> TestResult<Value> {
        let encoded = must(serde_json::to_string(&message), "request json")?;
        must(writeln!(self.stdin, "{encoded}"), "write request")?;
        must(self.stdin.flush(), "flush request")?;
        let mut line = String::new();
        let byte_count = must(self.stdout.read_line(&mut line), "read response")?;
        if byte_count == 0 {
            return Err(io::Error::other("unexpected EOF reading response").into());
        }
        must(serde_json::from_str(&line), "response json")
    }

    fn notify(&mut self, message: Value) -> TestResult {
        let encoded = must(serde_json::to_string(&message), "notify json")?;
        must(writeln!(self.stdin, "{encoded}"), "write notify")?;
        must(self.stdin.flush(), "flush notify")?;
        Ok(())
    }
}

impl Drop for McpHarness {
    fn drop(&mut self) {
        let _ = self.child.kill();
        let _ = self.child.wait();
    }
}

fn assert_tool_ok(response: &Value) {
    assert_eq!(
        response["result"]["isError"].as_bool(),
        Some(false),
        "tool response unexpectedly errored: {response:#}"
    );
}

fn assert_tool_error(response: &Value) {
    assert_eq!(
        response["result"]["isError"].as_bool(),
        Some(true),
        "tool response unexpectedly succeeded: {response:#}"
    );
}

fn tool_content(response: &Value) -> &Value {
    &response["result"]["structuredContent"]
}

fn tool_names(response: &Value) -> Vec<&str> {
    response["result"]["tools"]
        .as_array()
        .into_iter()
        .flatten()
        .filter_map(|tool| tool["name"].as_str())
        .collect()
}

fn write_fake_claude_script(path: &Path) -> TestResult {
    let script = r#"#!/bin/sh
set -eu
if [ -n "${PHONE_OPUS_TEST_PWD_FILE:-}" ]; then
  pwd >"$PHONE_OPUS_TEST_PWD_FILE"
fi
if [ -n "${PHONE_OPUS_TEST_ARGS_FILE:-}" ]; then
  printf '%s\n' "$@" >"$PHONE_OPUS_TEST_ARGS_FILE"
fi
if [ -n "${PHONE_OPUS_TEST_STDERR:-}" ]; then
  printf '%s\n' "$PHONE_OPUS_TEST_STDERR" >&2
fi
if [ -n "${PHONE_OPUS_TEST_STDOUT_FILE:-}" ]; then
  cat "$PHONE_OPUS_TEST_STDOUT_FILE"
fi
exit "${PHONE_OPUS_TEST_EXIT_CODE:-0}"
"#;
    must(fs::write(path, script), "write fake claude script")?;
    let mut permissions = must(fs::metadata(path), "fake claude metadata")?.permissions();
    permissions.set_mode(0o755);
    must(
        fs::set_permissions(path, permissions),
        "chmod fake claude script",
    )?;
    Ok(())
}

#[test]
fn cold_start_exposes_consult_and_ops_tools() -> TestResult {
    let root = temp_root("cold_start")?;
    let state_home = root.join("state-home");
    must(fs::create_dir_all(&state_home), "create state home")?;

    let mut harness = McpHarness::spawn(&state_home, &[])?;
    let initialize = harness.initialize()?;
    assert_eq!(
        initialize["result"]["protocolVersion"].as_str(),
        Some("2025-11-25")
    );
    harness.notify_initialized()?;

    let tools = harness.tools_list()?;
    let tool_names = tool_names(&tools);
    assert!(tool_names.contains(&"consult"));
    assert!(tool_names.contains(&"health_snapshot"));
    assert!(tool_names.contains(&"telemetry_snapshot"));

    let health = harness.call_tool(3, "health_snapshot", json!({}))?;
    assert_tool_ok(&health);
    assert_eq!(tool_content(&health)["worker_generation"].as_u64(), Some(1));
    Ok(())
}

#[test]
fn consult_uses_read_only_toolset_and_requested_working_directory() -> TestResult {
    let root = temp_root("consult_success")?;
    let state_home = root.join("state-home");
    let sandbox = root.join("sandbox");
    must(fs::create_dir_all(&state_home), "create state home")?;
    must(fs::create_dir_all(&sandbox), "create sandbox")?;

    let fake_claude = root.join("claude");
    let stdout_file = root.join("stdout.json");
    let args_file = root.join("args.txt");
    let pwd_file = root.join("pwd.txt");
    write_fake_claude_script(&fake_claude)?;
    must(
        fs::write(
            &stdout_file,
            serde_json::to_string(&json!({
                "type": "result",
                "subtype": "success",
                "is_error": false,
                "duration_ms": 1234,
                "duration_api_ms": 1200,
                "num_turns": 2,
                "result": "oracle",
                "stop_reason": "end_turn",
                "session_id": "session-123",
                "total_cost_usd": 0.125,
                "usage": {
                    "input_tokens": 10,
                    "output_tokens": 5
                },
                "modelUsage": {
                    "claude-sonnet-4-6": {
                        "inputTokens": 10,
                        "outputTokens": 5
                    }
                },
                "permission_denials": [],
                "fast_mode_state": "off",
                "uuid": "uuid-123"
            }))?,
        ),
        "write fake stdout",
    )?;

    let claude_bin = fake_claude.display().to_string();
    let stdout_path = stdout_file.display().to_string();
    let args_path = args_file.display().to_string();
    let pwd_path = pwd_file.display().to_string();
    let env = [
        ("PHONE_OPUS_CLAUDE_BIN", claude_bin.as_str()),
        ("PHONE_OPUS_TEST_STDOUT_FILE", stdout_path.as_str()),
        ("PHONE_OPUS_TEST_ARGS_FILE", args_path.as_str()),
        ("PHONE_OPUS_TEST_PWD_FILE", pwd_path.as_str()),
    ];
    let mut harness = McpHarness::spawn(&state_home, &env)?;
    let _ = harness.initialize()?;
    harness.notify_initialized()?;

    let consult = harness.call_tool(
        3,
        "consult",
        json!({
            "prompt": "say oracle",
            "cwd": sandbox.display().to_string(),
            "max_turns": 7
        }),
    )?;
    assert_tool_ok(&consult);
    assert_eq!(tool_content(&consult)["response"].as_str(), Some("oracle"));
    assert_eq!(
        tool_content(&consult)["cwd"].as_str(),
        Some(sandbox.display().to_string().as_str())
    );
    assert_eq!(tool_content(&consult)["num_turns"].as_u64(), Some(2));

    let pwd = must(fs::read_to_string(&pwd_file), "read fake pwd file")?;
    assert_eq!(pwd.trim(), sandbox.display().to_string());

    let args = must(fs::read_to_string(&args_file), "read fake args file")?;
    let lines = args.lines().collect::<Vec<_>>();
    assert!(lines.contains(&"-p"));
    assert!(lines.contains(&"--output-format"));
    assert!(lines.contains(&"json"));
    assert!(lines.contains(&"--strict-mcp-config"));
    assert!(lines.contains(&"--mcp-config"));
    assert!(lines.contains(&"{\"mcpServers\":{}}"));
    assert!(lines.contains(&"--disable-slash-commands"));
    assert!(lines.contains(&"--no-chrome"));
    assert!(lines.contains(&"--tools"));
    assert!(lines.contains(&"Bash,Read,Grep,Glob,LS,WebFetch,WebSearch"));
    assert!(lines.contains(&"--permission-mode"));
    assert!(lines.contains(&"dontAsk"));
    assert!(lines.contains(&"--max-turns"));
    assert!(lines.contains(&"7"));
    assert_eq!(lines.last().copied(), Some("say oracle"));

    let telemetry = harness.call_tool(4, "telemetry_snapshot", json!({}))?;
    assert_tool_ok(&telemetry);
    let hot_methods = tool_content(&telemetry)["hot_methods"]
        .as_array()
        .cloned()
        .unwrap_or_default();
    assert!(
        hot_methods
            .iter()
            .any(|value| value["method"] == "tools/call:consult")
    );
    Ok(())
}

#[test]
fn consult_surfaces_downstream_cli_failures() -> TestResult {
    let root = temp_root("consult_failure")?;
    let state_home = root.join("state-home");
    let fake_claude = root.join("claude");
    must(fs::create_dir_all(&state_home), "create state home")?;
    write_fake_claude_script(&fake_claude)?;

    let claude_bin = fake_claude.display().to_string();
    let env = [
        ("PHONE_OPUS_CLAUDE_BIN", claude_bin.as_str()),
        ("PHONE_OPUS_TEST_EXIT_CODE", "17"),
        ("PHONE_OPUS_TEST_STDERR", "permission denied by fake claude"),
    ];
    let mut harness = McpHarness::spawn(&state_home, &env)?;
    let _ = harness.initialize()?;
    harness.notify_initialized()?;

    let consult = harness.call_tool(3, "consult", json!({ "prompt": "fail" }))?;
    assert_tool_error(&consult);
    assert_eq!(
        tool_content(&consult)["fault"]["class"].as_str(),
        Some("downstream")
    );
    assert!(
        tool_content(&consult)["fault"]["detail"]
            .as_str()
            .is_some_and(|value| value.contains("permission denied by fake claude"))
    );
    Ok(())
}

#[test]
fn consult_never_replays_after_worker_transport_failure() -> TestResult {
    let root = temp_root("consult_no_replay")?;
    let state_home = root.join("state-home");
    let fake_claude = root.join("claude");
    must(fs::create_dir_all(&state_home), "create state home")?;
    write_fake_claude_script(&fake_claude)?;

    let claude_bin = fake_claude.display().to_string();
    let env = [
        ("PHONE_OPUS_CLAUDE_BIN", claude_bin.as_str()),
        (
            "PHONE_OPUS_MCP_TEST_WORKER_CRASH_ONCE_KEY",
            "tools/call:consult",
        ),
    ];
    let mut harness = McpHarness::spawn(&state_home, &env)?;
    let _ = harness.initialize()?;
    harness.notify_initialized()?;

    let consult = harness.call_tool(3, "consult", json!({ "prompt": "crash once" }))?;
    assert_tool_error(&consult);
    assert_eq!(
        tool_content(&consult)["fault"]["class"].as_str(),
        Some("transport")
    );
    assert_eq!(tool_content(&consult)["retryable"].as_bool(), Some(true));
    assert_eq!(tool_content(&consult)["retried"].as_bool(), Some(false));

    let telemetry = harness.call_tool(4, "telemetry_snapshot", json!({ "render": "json" }))?;
    assert_tool_ok(&telemetry);
    assert_eq!(tool_content(&telemetry)["retries"].as_u64(), Some(0));
    let hot_methods = tool_content(&telemetry)["hot_methods"]
        .as_array()
        .cloned()
        .unwrap_or_default();
    let consult_method = hot_methods
        .iter()
        .find(|value| value["method"] == "tools/call:consult")
        .cloned()
        .unwrap_or_default();
    assert_eq!(consult_method["transport_faults"].as_u64(), Some(1));

    let telemetry_log_path = state_home
        .join("phone_opus")
        .join("mcp")
        .join("telemetry.jsonl");
    let telemetry_rows = read_json_lines::<Value>(&telemetry_log_path)?;
    assert!(
        telemetry_rows
            .iter()
            .any(|row| row["event"] == "tool_call" && row["tool_name"] == "consult")
    );
    Ok(())
}