//! Line previewer CLI — content authoring tool (#193).
//!
//! Loads YAML content packs and previews dialogue/monologue lines with
//! simulated filter context. Designed for content authors to verify line
//! gating, prerequisite logic, and selection ordering before runtime.
//!
//! # Examples
//!
//! ```sh
//! # Monologue: show lines for smuggler character
//! cargo run --bin line_preview -- --character smuggler
//!
//! # Monologue with knowledge context and explain mode
//! cargo run --bin line_preview -- --character smuggler --knows smuggling_operation --explain
//!
//! # Dialogue: show lines for dock-worker at the-last-shift
//! cargo run --bin line_preview -- --role dock-worker --location the-last-shift \
//!     --access insider --trust real --situation bar_evening
//!
//! # Monologue sequence (priority-ordered)
//! cargo run --bin line_preview -- --character smuggler --location the-terminal --sequence
//! ```

use std::collections::BTreeSet;
use std::path::PathBuf;
use std::process;

use clap::Parser;

use settled_reach_server::content::line_pool::*;
use settled_reach_server::content::loader;

#[derive(Parser)]
#[command(
    name = "line_preview",
    about = "Preview dialogue and monologue lines from content packs"
)]
struct Args {
    /// Content directory root (must contain content.yaml)
    #[arg(long, default_value = "content")]
    content_root: PathBuf,

    // -- Mode detection --

    /// Character for monologue mode (smuggler, detective)
    #[arg(long)]
    character: Option<String>,

    /// NPC role for dialogue mode (e.g., dock-worker, bar-owner)
    #[arg(long)]
    role: Option<String>,

    // -- Shared --

    /// Location filter
    #[arg(long)]
    location: Option<String>,

    // -- Monologue options --

    /// Trigger filter for monologue (enter_location, observe_npc, etc.)
    #[arg(long)]
    trigger: Option<String>,

    /// Known facts for prerequisite checking (repeatable: --knows fact_a --knows fact_b)
    #[arg(long)]
    knows: Vec<String>,

    /// Show priority-ordered monologue sequence
    #[arg(long)]
    sequence: bool,

    // -- Dialogue options --

    /// Player access tier for dialogue (public, insider, authority, peer, hostile)
    #[arg(long, default_value = "public")]
    access: String,

    /// Player trust tier for dialogue (surface, real, secret)
    #[arg(long, default_value = "surface")]
    trust: String,

    /// Active situations for dialogue (comma-separated: --situation arrival,bar_evening)
    #[arg(long, value_delimiter = ',')]
    situation: Vec<String>,

    // -- Output control --

    /// Show filter reasoning for each line
    #[arg(long)]
    explain: bool,
}

fn main() {
    let args = Args::parse();

    // Load content
    let store = match loader::load_content(&args.content_root) {
        Ok(s) => s,
        Err(e) => {
            eprintln!(
                "Error: failed to load content from {:?}: {}",
                args.content_root, e
            );
            process::exit(1);
        }
    };

    // Build line pool index
    let index = LinePoolIndex::build(&store);
    eprintln!(
        "Loaded: {} dialogue lines, {} monologue lines",
        index.dialogue_line_count(),
        index.monologue_line_count()
    );

    // Route to mode based on flags
    if args.character.is_some() {
        run_monologue(&index, &args);
    } else if args.role.is_some() {
        run_dialogue(&index, &args);
    } else {
        print_summary(&index);
    }
}

// ---------------------------------------------------------------------------
// Summary mode — no mode flags, show what's available
// ---------------------------------------------------------------------------

fn print_summary(index: &LinePoolIndex) {
    println!("=== Content Summary ===\n");

    if !index.dialogue.is_empty() {
        println!("Dialogue pools:");
        for ((loc, role), pool) in &index.dialogue {
            println!("  {loc} / {role}: {} lines", pool.lines.len());
        }
    }

    if !index.monologue.is_empty() {
        println!("\nMonologue pools:");
        for ((character, loc), pool) in &index.monologue {
            let line_count: usize = pool.by_trigger.values().map(|v| v.len()).sum();
            let triggers: Vec<&str> = pool.by_trigger.keys().map(trigger_str).collect();
            println!(
                "  {} @ {loc}: {line_count} lines [{triggers}]",
                character_str(character),
                triggers = triggers.join(", ")
            );
        }
    }

    println!("\nUse --character <name> for monologue or --role <role> --location <loc> for dialogue.");
}

// ---------------------------------------------------------------------------
// Monologue mode
// ---------------------------------------------------------------------------

fn run_monologue(index: &LinePoolIndex, args: &Args) {
    let char_str = args.character.as_deref().unwrap();
    let character: Character = parse_or_exit(char_str, "character", "smuggler, detective");
    let known_facts: BTreeSet<&str> = args.knows.iter().map(|s| s.as_str()).collect();

    let trigger_filter: Option<Trigger> = args.trigger.as_deref().map(|t| {
        parse_or_exit(
            t,
            "trigger",
            "enter_location, observe_npc, hear_sound, observe_anomaly, \
             post_conversation, discover_evidence, witness_interaction, time_idle, return_visit",
        )
    });

    // Header
    println!("Mode: monologue");
    println!("Character: {}", character_str(&character));
    if let Some(loc) = &args.location {
        println!("Location: {}", loc);
    }
    if let Some(tf) = &trigger_filter {
        println!("Trigger: {}", trigger_str(tf));
    }
    if !known_facts.is_empty() {
        println!("Known facts: {}", args.knows.join(", "));
    }
    println!();

    // Collect matching pools
    let pools: Vec<_> = index
        .monologue
        .iter()
        .filter(|((c, loc), _)| {
            *c == character && args.location.as_ref().map_or(true, |l| loc == l)
        })
        .collect();

    if pools.is_empty() {
        println!("No monologue pools found for {}", character_str(&character));
        if let Some(loc) = &args.location {
            println!("  (location filter: {})", loc);
        }
        return;
    }

    if args.sequence {
        run_monologue_sequence(&pools, &known_facts, trigger_filter.as_ref());
        return;
    }

    let mut pass_count = 0u32;
    let mut fail_count = 0u32;

    for ((_, loc), pool) in &pools {
        println!("--- {} ---", loc);

        for (trigger, lines) in &pool.by_trigger {
            let trigger_match = trigger_filter.as_ref().map_or(true, |tf| trigger == tf);

            for line in lines {
                let prereq_pass = check_prerequisites(line, &known_facts);
                let overall = trigger_match && prereq_pass;

                if args.explain {
                    let mark = if overall { "PASS" } else { "FAIL" };
                    println!(
                        "\n  [{}] {} (pri:{} cd:{})",
                        mark, line.id, line.priority, line.cooldown
                    );
                    if trigger_filter.is_some() {
                        println!(
                            "    trigger: {} {}",
                            trigger_str(trigger),
                            if trigger_match { "+" } else { "- (filtered)" }
                        );
                    } else {
                        println!("    trigger: {}", trigger_str(trigger));
                    }
                    print_prereq_detail(line, &known_facts);
                    if !line.tags.is_empty() {
                        println!("    tags: [{}]", line.tags.join(", "));
                    }
                    println!("    \"{}\"", line.text);
                } else if overall {
                    println!(
                        "  [{:>2}] [{}] {} \"{}\"",
                        line.priority,
                        trigger_str(trigger),
                        line.id,
                        line.text
                    );
                }

                if overall {
                    pass_count += 1;
                } else {
                    fail_count += 1;
                }
            }
        }
    }

    println!("\n{} matched, {} filtered", pass_count, fail_count);
}

// ---------------------------------------------------------------------------
// Monologue sequence mode — priority-ordered preview
// ---------------------------------------------------------------------------

fn run_monologue_sequence(
    pools: &[(&(Character, String), &IndexedMonologuePool)],
    known_facts: &BTreeSet<&str>,
    trigger_filter: Option<&Trigger>,
) {
    println!("=== Sequence Preview (priority order) ===\n");

    // Collect all passing lines across pools and triggers
    let mut all_lines: Vec<(&str, &Trigger, &IndexedMonologueLine)> = Vec::new();

    for ((_, loc), pool) in pools {
        for (trigger, lines) in &pool.by_trigger {
            if let Some(tf) = trigger_filter {
                if trigger != tf {
                    continue;
                }
            }
            for line in lines {
                if check_prerequisites(line, known_facts) {
                    all_lines.push((loc.as_str(), trigger, line));
                }
            }
        }
    }

    // Sort by priority descending, then by id for determinism
    all_lines.sort_by(|a, b| {
        b.2.priority
            .cmp(&a.2.priority)
            .then_with(|| a.2.id.cmp(&b.2.id))
    });

    if all_lines.is_empty() {
        println!("  (no matching lines)");
        return;
    }

    for (i, (loc, trigger, line)) in all_lines.iter().enumerate() {
        println!(
            "  {:>2}. [pri:{:>2}] [{}] [{}] {}",
            i + 1,
            line.priority,
            trigger_str(trigger),
            loc,
            line.id,
        );
        println!("      \"{}\"", line.text);
    }

    println!("\n{} lines in sequence", all_lines.len());
}

// ---------------------------------------------------------------------------
// Dialogue mode
// ---------------------------------------------------------------------------

fn run_dialogue(index: &LinePoolIndex, args: &Args) {
    let role = args.role.as_deref().unwrap();
    let location = args.location.as_deref().unwrap_or_else(|| {
        eprintln!("Error: --location is required for dialogue mode");
        process::exit(1)
    });

    let access: AccessTier = parse_or_exit(
        &args.access,
        "access",
        "public, insider, authority, peer, hostile",
    );
    let trust: TrustTier = parse_or_exit(&args.trust, "trust", "surface, real, secret");

    let situations: Vec<Situation> = if args.situation.is_empty() {
        vec![Situation::Arrival]
    } else {
        args.situation
            .iter()
            .map(|s| {
                parse_or_exit(
                    s,
                    "situation",
                    "arrival, shift_start, shift_end, shift_transition, bar_evening, \
                     night_shift, investigation, confrontation, social, alone, \
                     emergency, routine, observation, greeting",
                )
            })
            .collect()
    };

    // Header
    println!("Mode: dialogue");
    println!("Location: {}, Role: {}", location, role);
    println!(
        "Access: {}, Trust: {}",
        access_str(&access),
        trust_str(&trust)
    );
    println!(
        "Situations: [{}]",
        situations
            .iter()
            .map(situation_str)
            .collect::<Vec<_>>()
            .join(", ")
    );
    println!();

    let key = (location.to_string(), role.to_string());
    let Some(pool) = index.dialogue.get(&key) else {
        println!(
            "No dialogue pool found for {} / {}",
            location, role
        );
        return;
    };

    if args.explain {
        run_dialogue_explain(pool, access, trust, &situations);
    } else {
        let results = index.query_dialogue(location, role, access, &situations, trust);

        if results.is_empty() {
            println!("No matching lines.");
            return;
        }

        for line in &results {
            println!("  {} \"{}\"", line.id, line.text);
            if !line.topic.is_empty() || !line.mood.is_empty() {
                println!(
                    "    topic: [{}] mood: [{}]",
                    line.topic
                        .iter()
                        .map(topic_str)
                        .collect::<Vec<_>>()
                        .join(", "),
                    line.mood
                        .iter()
                        .map(mood_str)
                        .collect::<Vec<_>>()
                        .join(", ")
                );
            }
        }

        println!("\n{} lines matched", results.len());
    }
}

fn run_dialogue_explain(
    pool: &IndexedDialoguePool,
    access: AccessTier,
    trust: TrustTier,
    situations: &[Situation],
) {
    let mut pass_count = 0u32;
    let mut fail_count = 0u32;

    for line in &pool.lines {
        let l1 = line.access.contains(&access);
        let l2 = line.situation.iter().any(|s| situations.contains(s));
        let l3 = trust.meets(line.trust);
        let overall = l1 && l2 && l3;
        let mark = if overall { "PASS" } else { "FAIL" };

        println!("[{}] {}", mark, line.id);
        println!(
            "  L1 access: requires [{}], player has {} {}",
            line.access
                .iter()
                .map(access_str)
                .collect::<Vec<_>>()
                .join(", "),
            access_str(&access),
            if l1 { "+" } else { "-" }
        );
        println!(
            "  L2 situation: requires [{}], active [{}] {}",
            line.situation
                .iter()
                .map(situation_str)
                .collect::<Vec<_>>()
                .join(", "),
            situations
                .iter()
                .map(situation_str)
                .collect::<Vec<_>>()
                .join(", "),
            if l2 { "+" } else { "-" }
        );
        println!(
            "  L3 trust: requires {}, player has {} {}",
            trust_str(&line.trust),
            trust_str(&trust),
            if l3 { "+" } else { "-" }
        );
        if !line.topic.is_empty() || !line.mood.is_empty() {
            println!(
                "  L4 topic: [{}], mood: [{}]",
                line.topic
                    .iter()
                    .map(topic_str)
                    .collect::<Vec<_>>()
                    .join(", "),
                line.mood
                    .iter()
                    .map(mood_str)
                    .collect::<Vec<_>>()
                    .join(", ")
            );
        }
        println!("  \"{}\"", line.text);
        println!();

        if overall {
            pass_count += 1;
        } else {
            fail_count += 1;
        }
    }

    println!("{} passed, {} filtered", pass_count, fail_count);
}

// ---------------------------------------------------------------------------
// Prerequisite checking
// ---------------------------------------------------------------------------

/// Check monologue line prerequisites against known facts.
///
/// Fact prerequisites pass if the fact_id is in the known set.
/// Entity attributes and relationships require runtime state and are
/// treated as passing (shown as unchecked in explain mode).
fn check_prerequisites(line: &IndexedMonologueLine, known_facts: &BTreeSet<&str>) -> bool {
    let Some(prereqs) = &line.prerequisites else {
        return true;
    };

    prereqs
        .facts
        .iter()
        .all(|f| known_facts.contains(f.fact_id.as_str()))
}

/// Print prerequisite detail for explain mode.
fn print_prereq_detail(line: &IndexedMonologueLine, known_facts: &BTreeSet<&str>) {
    let Some(prereqs) = &line.prerequisites else {
        println!("    prerequisites: none");
        return;
    };

    println!("    prerequisites:");

    for fact in &prereqs.facts {
        let has_it = known_facts.contains(fact.fact_id.as_str());
        println!(
            "      fact {} >= {} {}",
            fact.fact_id,
            fact.min_confidence,
            if has_it { "+" } else { "- (not in --knows)" }
        );
    }

    for attr in &prereqs.entity_attributes {
        println!(
            "      entity_attr {}.{} == {} ? (unchecked — needs runtime)",
            attr.entity, attr.key, attr.value
        );
    }

    if let Some(rel) = &prereqs.relationship {
        let target = rel.target.as_deref().unwrap_or("?");
        let state = rel.state.as_deref().unwrap_or("?");
        println!(
            "      relationship {} state={} ? (unchecked — needs runtime)",
            target, state
        );
    }
}

// ---------------------------------------------------------------------------
// Enum → string helpers (mirrors FromStr in line_pool.rs)
// ---------------------------------------------------------------------------

fn parse_or_exit<T: std::str::FromStr>(s: &str, kind: &str, valid: &str) -> T {
    s.parse().unwrap_or_else(|_| {
        eprintln!("Error: invalid {} '{}'. Valid: {}", kind, s, valid);
        process::exit(1)
    })
}

fn character_str(c: &Character) -> &'static str {
    match c {
        Character::Smuggler => "smuggler",
        Character::Detective => "detective",
    }
}

fn access_str(t: &AccessTier) -> &'static str {
    match t {
        AccessTier::Public => "public",
        AccessTier::Insider => "insider",
        AccessTier::Authority => "authority",
        AccessTier::Peer => "peer",
        AccessTier::Hostile => "hostile",
    }
}

fn trust_str(t: &TrustTier) -> &'static str {
    match t {
        TrustTier::Surface => "surface",
        TrustTier::Real => "real",
        TrustTier::Secret => "secret",
    }
}

fn situation_str(s: &Situation) -> &'static str {
    match s {
        Situation::Arrival => "arrival",
        Situation::ShiftStart => "shift_start",
        Situation::ShiftEnd => "shift_end",
        Situation::ShiftTransition => "shift_transition",
        Situation::BarEvening => "bar_evening",
        Situation::NightShift => "night_shift",
        Situation::Investigation => "investigation",
        Situation::Confrontation => "confrontation",
        Situation::Social => "social",
        Situation::Alone => "alone",
        Situation::Emergency => "emergency",
        Situation::Routine => "routine",
        Situation::Observation => "observation",
        Situation::Greeting => "greeting",
    }
}

fn trigger_str(t: &Trigger) -> &'static str {
    match t {
        Trigger::EnterLocation => "enter_location",
        Trigger::ObserveNpc => "observe_npc",
        Trigger::HearSound => "hear_sound",
        Trigger::ObserveAnomaly => "observe_anomaly",
        Trigger::PostConversation => "post_conversation",
        Trigger::DiscoverEvidence => "discover_evidence",
        Trigger::WitnessInteraction => "witness_interaction",
        Trigger::TimeIdle => "time_idle",
        Trigger::ReturnVisit => "return_visit",
    }
}

fn topic_str(t: &Topic) -> &'static str {
    match t {
        Topic::Colleague => "colleague",
        Topic::Routine => "routine",
        Topic::Cargo => "cargo",
        Topic::Money => "money",
        Topic::Trust => "trust",
        Topic::Danger => "danger",
        Topic::Institution => "institution",
        Topic::Personal => "personal",
        Topic::Investigation => "investigation",
    }
}

fn mood_str(m: &Mood) -> &'static str {
    match m {
        Mood::Anxious => "anxious",
        Mood::Frustrated => "frustrated",
        Mood::Content => "content",
        Mood::Suspicious => "suspicious",
        Mood::Warm => "warm",
        Mood::Hostile => "hostile",
        Mood::Relieved => "relieved",
        Mood::Focused => "focused",
    }
}