//! Regression & E2E tests for REPL commands and input processing.
//!
//! Slash-command dispatch tests live in `repl.rs` (inline `#[cfg(test)]`).
//! This file covers input processing, display regressions, and structural
//! assertions that are better expressed at the integration level.

mod input_processing {
    use std::fs;
    use tempfile::TempDir;

    fn process_input(input: &str, project_root: &std::path::Path) -> (String, Vec<String>) {
        let mut prompt_parts = Vec::new();
        let mut files_loaded = Vec::new();

        for token in input.split_whitespace() {
            if let Some(raw_path) = token.strip_prefix('@') {
                if raw_path.is_empty() {
                    prompt_parts.push(token.to_string());
                    continue;
                }
                let full_path = project_root.join(raw_path);
                if full_path.is_file() {
                    files_loaded.push(raw_path.to_string());
                } else {
                    prompt_parts.push(token.to_string());
                }
            } else {
                prompt_parts.push(token.to_string());
            }
        }

        let prompt = prompt_parts.join(" ");
        let prompt = if prompt.trim().is_empty() && !files_loaded.is_empty() {
            "Describe and explain the attached files.".to_string()
        } else {
            prompt
        };

        (prompt, files_loaded)
    }

    #[test]
    fn test_at_file_reference_resolved() {
        let dir = TempDir::new().unwrap();
        fs::write(dir.path().join("main.rs"), "fn main() {}").unwrap();
        let (prompt, files) = process_input("explain @main.rs", dir.path());
        assert_eq!(prompt, "explain");
        assert_eq!(files, vec!["main.rs"]);
    }

    #[test]
    fn test_at_file_missing_stays_in_prompt() {
        let dir = TempDir::new().unwrap();
        let (prompt, files) = process_input("explain @nonexistent.rs", dir.path());
        assert!(prompt.contains("@nonexistent.rs"));
        assert!(files.is_empty());
    }

    #[test]
    fn test_at_file_only_gets_default_prompt() {
        let dir = TempDir::new().unwrap();
        fs::write(dir.path().join("code.py"), "x = 1").unwrap();
        let (prompt, files) = process_input("@code.py", dir.path());
        assert_eq!(prompt, "Describe and explain the attached files.");
        assert_eq!(files.len(), 1);
    }

    #[test]
    fn test_multiple_at_files() {
        let dir = TempDir::new().unwrap();
        fs::write(dir.path().join("a.rs"), "a").unwrap();
        fs::write(dir.path().join("b.rs"), "b").unwrap();
        let (prompt, files) = process_input("compare @a.rs @b.rs", dir.path());
        assert_eq!(prompt, "compare");
        assert_eq!(files.len(), 2);
    }

    #[test]
    fn test_bare_at_sign_ignored() {
        let dir = TempDir::new().unwrap();
        let (prompt, files) = process_input("email me @ noon", dir.path());
        assert_eq!(prompt, "email me @ noon");
        assert!(files.is_empty());
    }

    #[test]
    fn test_no_at_references() {
        let dir = TempDir::new().unwrap();
        let (prompt, files) = process_input("just a question", dir.path());
        assert_eq!(prompt, "just a question");
        assert!(files.is_empty());
    }
}

mod completions {
    /// The slash commands that should appear in tab completion.
    const EXPECTED_COMMANDS: &[&str] = &[
        "/agent",
        "/compact",
        "/cost",
        "/diff",
        "/help",
        "/memory",
        "/model",
        "/provider",
        "/sessions",
        "/skills",
    ];

    /// Commands that should NOT appear in completions.
    const REMOVED_COMMANDS: &[&str] = &["/key", "/transcript", "/export"];

    #[test]
    fn test_expected_commands_present() {
        assert_eq!(EXPECTED_COMMANDS.len(), 10, "Expected 10 slash commands");
        for cmd in EXPECTED_COMMANDS {
            assert!(
                EXPECTED_COMMANDS.contains(cmd),
                "Expected command {cmd} missing from completions"
            );
        }
    }

    #[test]
    fn test_removed_commands_absent() {
        for cmd in REMOVED_COMMANDS {
            assert!(
                !EXPECTED_COMMANDS.contains(cmd),
                "Removed command {cmd} should not be in completions"
            );
        }
    }
}

mod display_regression {
    /// All tool names that should map to known labels.
    const KNOWN_TOOLS: &[(&str, &str)] = &[
        ("Read", "Read"),
        ("List", "List"),
        ("Write", "Write"),
        ("Edit", "Edit"),
        ("Delete", "Delete"),
        ("Grep", "Search"),
        ("Glob", "Glob"),
        ("Bash", "Shell"),
        ("WebFetch", "Fetch"),
        ("MemoryRead", "Memory"),
        ("MemoryWrite", "Memory"),
        ("ShareReasoning", "Tool"),
        ("InvokeAgent", "Agent"),
        ("ListAgents", "Tool"),
        ("TodoWrite", "Todo"),
        ("TodoRead", "Todo"),
        ("AstAnalysis", "AST"),
    ];

    fn tool_label(name: &str) -> &'static str {
        match name {
            "Read" => "Read",
            "List" => "List",
            "Write" => "Write",
            "Edit" => "Edit",
            "Delete" => "Delete",
            "Grep" => "Search",
            "Glob" => "Glob",
            "Bash" => "Shell",
            "WebFetch" => "Fetch",
            "MemoryRead" | "MemoryWrite" => "Memory",
            "InvokeAgent" => "Agent",
            "TodoWrite" | "TodoRead" => "Todo",
            "AstAnalysis" => "AST",
            _ => "Tool",
        }
    }

    #[test]
    fn test_all_tools_have_banners() {
        for (tool, expected_label) in KNOWN_TOOLS {
            assert_eq!(
                tool_label(tool),
                *expected_label,
                "Tool '{tool}' should have label '{expected_label}'"
            );
        }
    }

    #[test]
    fn test_unknown_tool_gets_generic_banner() {
        assert_eq!(tool_label("some_new_tool"), "Tool");
    }

    #[test]
    fn test_tool_count() {
        assert_eq!(
            KNOWN_TOOLS.len(),
            17,
            "Expected 17 known tools (update this test when adding tools)"
        );
    }
}

mod event_loop_structure {
    /// Regression test for the v0.1.11 frozen-input bug.
    ///
    /// The idle event loop in `run_event_loop` MUST call `self.draw()` before
    /// blocking on `tokio::select!` for keyboard events. Without it the
    /// viewport never redraws after keystrokes and input appears frozen.
    ///
    /// This is a source-level structural assertion — the only reliable way to
    /// guard against accidental removal during refactors.
    #[test]
    fn draw_called_before_idle_select_in_event_loop() {
        let source = include_str!("../src/tui_context/mod.rs");

        // Locate run_event_loop
        let fn_start = source
            .find("async fn run_event_loop")
            .expect("run_event_loop function not found in tui_context.rs");
        let body = &source[fn_start..];

        // Find the idle select! block (the one with crossterm_events.next())
        let select_marker = "self.crossterm_events.next()";
        let select_pos = body
            .find(select_marker)
            .expect("idle select! with crossterm_events.next() not found in run_event_loop");

        // self.draw() must appear (uncommented) between fn start and the select!
        let before_select = &body[..select_pos];
        let has_active_draw = before_select.lines().any(|line| {
            let trimmed = line.trim();
            !trimmed.starts_with("//") && trimmed.contains("self.draw()")
        });
        assert!(
            has_active_draw,
            "self.draw() must be called (uncommented) before the idle tokio::select! in \
             run_event_loop. Without it the viewport never redraws and input appears \
             frozen (v0.1.11 bug)."
        );
    }
}

mod provider_key_flow {
    #[test]
    fn test_same_provider_should_prompt_for_key() {
        let current_provider = "openai";
        let selected_provider = "openai";
        let is_same = current_provider == selected_provider;
        let is_local = selected_provider == "lmstudio";
        let key_exists = true;
        let should_prompt = !is_local && (is_same || !key_exists);
        assert!(should_prompt);
    }

    #[test]
    fn test_new_provider_without_key_prompts() {
        let is_same = false;
        let is_local = false;
        let key_exists = false;
        let should_prompt = !is_local && (is_same || !key_exists);
        assert!(should_prompt);
    }

    #[test]
    fn test_new_provider_with_key_skips_prompt() {
        let is_same = false;
        let is_local = false;
        let key_exists = true;
        let should_prompt = !is_local && (is_same || !key_exists);
        assert!(!should_prompt);
    }

    #[test]
    fn test_lmstudio_never_prompts_for_key() {
        let is_local = true;
        let should_prompt = !is_local;
        assert!(!should_prompt);
    }
}

/// Regression test for #982: `--mode safe` was silently overridden by a
/// hardcoded `TrustMode::Auto` at every `KodaSession::new` call site.
///
/// We can't cheaply unit-test the headless / server / TUI bootstrap paths
/// without a real provider, terminal, and database. Instead, this is a
/// structural test: scan the source files that previously held the hardcoded
/// `TrustMode::Auto` literal as the 5th argument to `KodaSession::new` and
/// assert it's gone. The fix should pass `config.trust` (or `state.config.trust`)
/// instead.
///
/// If a future refactor reintroduces the hardcode, this test fails with a
/// clear diagnostic pointing at the file.
mod hardcoded_trust_mode_at_session_creation {
    use std::fs;
    use std::path::Path;

    fn assert_no_hardcoded_auto_in_session_new(path: &str) {
        let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
        // Tests run with CWD = workspace member dir; resolve from there.
        let full_path = manifest_dir.join("..").join(path);
        let src = fs::read_to_string(&full_path)
            .unwrap_or_else(|e| panic!("read {}: {}", full_path.display(), e));

        // Look for `KodaSession::new(...)` blocks containing `TrustMode::Auto`
        // as one of the args. Multi-line, so scan window-by-window between
        // the call's `(` and its matching `)` (heuristic: until next bare `)`).
        let mut idx = 0;
        while let Some(start) = src[idx..].find("KodaSession::new(") {
            let abs_start = idx + start;
            // crude end: first ").await" or ")\n .await" within next 600 chars
            let window_end = (abs_start + 600).min(src.len());
            let window = &src[abs_start..window_end];
            assert!(
                !window.contains("TrustMode::Auto"),
                "{}: KodaSession::new(...) call still passes hardcoded TrustMode::Auto. \
                 Pass `config.trust` (or equivalent) instead. See #982.\n\nWindow:\n{}",
                path,
                window
            );
            idx = abs_start + "KodaSession::new(".len();
        }
    }

    #[test]
    fn headless_path_does_not_hardcode_auto() {
        assert_no_hardcoded_auto_in_session_new("koda-cli/src/headless.rs");
    }

    #[test]
    fn acp_server_path_does_not_hardcode_auto() {
        assert_no_hardcoded_auto_in_session_new("koda-cli/src/server.rs");
    }

    #[test]
    fn tui_context_path_does_not_hardcode_auto() {
        assert_no_hardcoded_auto_in_session_new("koda-cli/src/tui_context/mod.rs");
    }
}

/// **#1022 B19** \u{2014} sub-agent dispatch must clamp child trust against
/// the **runtime** trust mode (the `mode` parameter), not the
/// **stale startup** value `parent_config.trust`.
///
/// `cycle_trust` and `set_trust` mutate the `SharedTrustMode` atomic
/// but never the `KodaConfig.trust` field. Pre-fix, sub_agent_dispatch
/// passed `parent_config.trust` as the parent side of the clamp, so a
/// user who started in Auto and hit `/safe` would still get sub-agents
/// clamped against Auto \u{2014} the child could run with broader privileges
/// than the parent's *current* mode. Real escalation.
///
/// The fix routes all three dispatch paths (fork/named/bg) through
/// `derive_child_trust(mode, declared)`. This test scans
/// `sub_agent_dispatch.rs` for the antipatterns
/// (`clamp(parent_config.trust,` or `derive_child_trust(parent_config.trust,`)
/// and fails with a clear pointer if either reappears.
///
/// Why structural and not e2e: an e2e test would need to (1) toggle
/// trust mid-session, (2) dispatch a sub-agent, (3) introspect the
/// child's effective trust. That's a heavy harness for a one-line
/// regression. The structural test catches the only way the bug
/// reintroduces.
mod sub_agent_dispatch_uses_runtime_trust_not_stale_config {
    use std::fs;
    use std::path::Path;

    #[test]
    fn no_clamp_or_derive_against_parent_config_trust() {
        let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
        let path = manifest_dir
            .join("..")
            .join("koda-core/src/sub_agent_dispatch.rs");
        let src =
            fs::read_to_string(&path).unwrap_or_else(|e| panic!("read {}: {}", path.display(), e));

        // Strip rustdoc + line comments before scanning so the
        // "antipattern this helper exists to prevent" prose in
        // doc comments doesn't trip the lint. Cheap pass: drop
        // anything from `//` to end of line. Block comments are
        // unused in this file but `///` is a `//` so it falls out
        // naturally.
        let code: String = src
            .lines()
            .map(|line| {
                if let Some(idx) = line.find("//") {
                    &line[..idx]
                } else {
                    line
                }
            })
            .collect::<Vec<_>>()
            .join("\n");

        for needle in [
            "clamp(parent_config.trust",
            "derive_child_trust(parent_config.trust",
        ] {
            assert!(
                !code.contains(needle),
                "sub_agent_dispatch.rs uses `{needle}` \u{2014} this is the \
                 #1022 B19 antipattern. `parent_config.trust` is the \
                 stale startup value; runtime trust toggles never \
                 update it. Pass the runtime `mode` parameter instead. \
                 See `derive_child_trust` doc in `koda-core/src/trust.rs`."
            );
        }

        // Positive assertion: the helper *is* called somewhere.
        // Catches a refactor that drops trust derivation entirely.
        assert!(
            code.contains("derive_child_trust("),
            "sub_agent_dispatch.rs no longer calls `derive_child_trust` \
             at all \u{2014} child trust derivation has been bypassed. \
             Every fork/named/bg path must derive child trust through \
             this helper."
        );
    }
}
