mod command;
mod draw;
mod formula;
mod import;
mod model;
mod persistence;
mod ui;
mod view;

use crate::import::csv_parser::csv_path_p;

use std::path::PathBuf;

use anyhow::{Context, Result};
use clap::{Parser, Subcommand};

use command::CommandResult;
use draw::run_tui;
use model::Model;
use serde_json::Value;

#[derive(Parser)]
#[command(name = "improvise", about = "Multi-dimensional data modeling TUI")]
struct Cli {
    /// Model file to open or create
    file: Option<PathBuf>,

    #[command(subcommand)]
    command: Option<Commands>,
}

#[derive(Subcommand)]
enum Commands {
    /// Import JSON or CSV data, then open TUI (or save with --output)
    Import {
        /// Files to import (multiple CSVs merge with a "File" category)
        files: Vec<PathBuf>,

        /// Mark field as category dimension (repeatable)
        #[arg(long)]
        category: Vec<String>,

        /// Mark field as numeric measure (repeatable)
        #[arg(long)]
        measure: Vec<String>,

        /// Mark field as time/date category (repeatable)
        #[arg(long)]
        time: Vec<String>,

        /// Skip/exclude a field from import (repeatable)
        #[arg(long)]
        skip: Vec<String>,

        /// Extract date component, e.g. "Date:Month" (repeatable)
        #[arg(long)]
        extract: Vec<String>,

        /// Set category axis, e.g. "Payee:row" (repeatable)
        #[arg(long)]
        axis: Vec<String>,

        /// Add formula, e.g. "Profit = Revenue - Cost" (repeatable)
        #[arg(long)]
        formula: Vec<String>,

        /// Model name (default: "Imported Model")
        #[arg(long)]
        name: Option<String>,

        /// Skip the interactive wizard
        #[arg(long)]
        no_wizard: bool,

        /// Save to file instead of opening TUI
        #[arg(short, long)]
        output: Option<PathBuf>,
    },

    /// Run a JSON command headless (repeatable)
    Cmd {
        /// JSON command strings
        json: Vec<String>,

        /// Model file to load/save
        #[arg(short, long)]
        file: Option<PathBuf>,
    },

    /// Run commands from a script file headless
    Script {
        /// Script file (one JSON command per line, # comments)
        path: PathBuf,

        /// Model file to load/save
        #[arg(short, long)]
        file: Option<PathBuf>,
    },
}

fn main() -> Result<()> {
    let cli = Cli::parse();

    match cli.command {
        None => {
            let model = get_initial_model(&cli.file)?;
            run_tui(model, cli.file, None)
        }

        Some(Commands::Import {
            files,
            category,
            measure,
            time,
            skip,
            extract,
            axis,
            formula,
            name,
            no_wizard,
            output,
        }) => {
            let import_value = if files.is_empty() {
                anyhow::bail!("No files specified for import");
            } else {
                get_import_data(&files)
                    .ok_or_else(|| anyhow::anyhow!("Failed to parse import files"))?
            };

            let config = ImportConfig {
                categories: category,
                measures: measure,
                time_fields: time,
                skip_fields: skip,
                extractions: parse_colon_pairs(&extract),
                axes: parse_colon_pairs(&axis),
                formulas: formula,
                name,
            };

            if no_wizard {
                run_headless_import(import_value, &config, output, cli.file)
            } else {
                run_wizard_import(import_value, &config, cli.file)
            }
        }

        Some(Commands::Cmd { json, file }) => run_headless_commands(&json, &file),

        Some(Commands::Script { path, file }) => run_headless_script(&path, &file),
    }
}

// ── Import config ────────────────────────────────────────────────────────────

struct ImportConfig {
    categories: Vec<String>,
    measures: Vec<String>,
    time_fields: Vec<String>,
    skip_fields: Vec<String>,
    extractions: Vec<(String, String)>,
    axes: Vec<(String, String)>,
    formulas: Vec<String>,
    name: Option<String>,
}

fn parse_colon_pairs(args: &[String]) -> Vec<(String, String)> {
    args.iter()
        .filter_map(|s| {
            let (a, b) = s.split_once(':')?;
            Some((a.to_string(), b.to_string()))
        })
        .collect()
}

fn apply_config_to_pipeline(
    pipeline: &mut import::wizard::ImportPipeline,
    config: &ImportConfig,
) {
    use import::analyzer::{DateComponent, FieldKind};

    // Override field kinds
    for p in &mut pipeline.proposals {
        if config.categories.contains(&p.field) {
            p.kind = FieldKind::Category;
            p.accepted = true;
        } else if config.measures.contains(&p.field) {
            p.kind = FieldKind::Measure;
            p.accepted = true;
        } else if config.time_fields.contains(&p.field) {
            p.kind = FieldKind::TimeCategory;
            p.accepted = true;
        } else if config.skip_fields.contains(&p.field) {
            p.accepted = false;
        }
    }

    // Apply date component extractions
    for (field, comp_str) in &config.extractions {
        let component = match comp_str.to_lowercase().as_str() {
            "year" => DateComponent::Year,
            "month" => DateComponent::Month,
            "quarter" => DateComponent::Quarter,
            _ => continue,
        };
        for p in &mut pipeline.proposals {
            if p.field == *field && !p.date_components.contains(&component) {
                p.date_components.push(component);
            }
        }
    }

    // Set formulas
    pipeline.formulas = config.formulas.clone();

    // Set model name
    if let Some(ref name) = config.name {
        pipeline.model_name = name.clone();
    }
}

fn apply_axis_overrides(model: &mut Model, axes: &[(String, String)]) {
    use view::Axis;
    let view = model.active_view_mut();
    for (cat, axis_str) in axes {
        let axis = match axis_str.to_lowercase().as_str() {
            "row" => Axis::Row,
            "column" | "col" => Axis::Column,
            "page" => Axis::Page,
            "none" => Axis::None,
            _ => continue,
        };
        view.set_axis(cat, axis);
    }
}

fn run_headless_import(
    import_value: Value,
    config: &ImportConfig,
    output: Option<PathBuf>,
    model_file: Option<PathBuf>,
) -> Result<()> {
    let mut pipeline = import::wizard::ImportPipeline::new(import_value);
    apply_config_to_pipeline(&mut pipeline, config);
    let mut model = pipeline.build_model()?;
    model.normalize_view_state();
    apply_axis_overrides(&mut model, &config.axes);

    if let Some(path) = output.or(model_file) {
        persistence::save(&model, &path)?;
        eprintln!("Saved to {}", path.display());
    } else {
        eprintln!("No output path specified; use -o <path> or provide a model file");
    }
    Ok(())
}

fn run_wizard_import(
    import_value: Value,
    _config: &ImportConfig,
    model_file: Option<PathBuf>,
) -> Result<()> {
    let model = get_initial_model(&model_file)?;
    // Pre-configure will happen inside the TUI via the wizard
    // For now, pass import_value and let the wizard handle it
    // TODO: pass config to wizard for pre-population
    run_tui(model, model_file, Some(import_value))
}

// ── Import data loading ──────────────────────────────────────────────────────

fn get_import_data(paths: &[PathBuf]) -> Option<Value> {
    let all_csv = paths.iter().all(|p| csv_path_p(p));

    if paths.len() > 1 {
        if !all_csv {
            eprintln!("Multi-file import only supports CSV files");
            return None;
        }
        match crate::import::csv_parser::merge_csvs(paths) {
            Ok(records) => Some(Value::Array(records)),
            Err(e) => {
                eprintln!("CSV merge error: {e}");
                None
            }
        }
    } else {
        let path = &paths[0];
        match std::fs::read_to_string(path) {
            Err(e) => {
                eprintln!("Cannot read '{}': {e}", path.display());
                None
            }
            Ok(content) => {
                if csv_path_p(path) {
                    match crate::import::csv_parser::parse_csv(path) {
                        Ok(records) => Some(Value::Array(records)),
                        Err(e) => {
                            eprintln!("CSV parse error: {e}");
                            None
                        }
                    }
                } else {
                    match serde_json::from_str::<Value>(&content) {
                        Err(e) => {
                            eprintln!("JSON parse error: {e}");
                            None
                        }
                        Ok(json) => Some(json),
                    }
                }
            }
        }
    }
}

// ── Headless command execution ───────────────────────────────────────────────

fn run_headless_commands(cmds: &[String], file: &Option<PathBuf>) -> Result<()> {
    let mut model = get_initial_model(file)?;
    let mut exit_code = 0;

    for line in cmds {
        let parsed = match command::parse_line(line) {
            Ok(cmds) => cmds,
            Err(e) => {
                let r = CommandResult::err(format!("Parse error: {e}"));
                println!("{}", serde_json::to_string(&r)?);
                exit_code = 1;
                continue;
            }
        };
        for cmd in &parsed {
            let result = command::dispatch(&mut model, cmd);
            if !result.ok {
                exit_code = 1;
            }
            println!("{}", serde_json::to_string(&result)?);
        }
    }

    if let Some(path) = file {
        persistence::save(&model, path)?;
    }

    std::process::exit(exit_code);
}

fn run_headless_script(script_path: &PathBuf, file: &Option<PathBuf>) -> Result<()> {
    let content = std::fs::read_to_string(script_path)?;
    let lines: Vec<String> = content.lines().map(String::from).collect();
    run_headless_commands(&lines, file)
}

// ── Helpers ──────────────────────────────────────────────────────────────────

fn get_initial_model(file_path: &Option<PathBuf>) -> Result<Model> {
    if let Some(ref path) = file_path {
        if path.exists() {
            let mut m = persistence::load(path)
                .with_context(|| format!("Failed to load {}", path.display()))?;
            m.normalize_view_state();
            Ok(m)
        } else {
            let name = path
                .file_stem()
                .and_then(|s| s.to_str())
                .unwrap_or("New Model")
                .to_string();
            Ok(Model::new(name))
        }
    } else {
        Ok(Model::new("New Model"))
    }
}