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

use goose::config::{Config, ExtensionConfig};

use crate::commands::bench::agent_generator;
use crate::commands::configure::handle_configure;
use crate::commands::info::handle_info;
use crate::commands::mcp::run_server;
use crate::commands::recipe::{handle_deeplink, handle_validate};
use crate::commands::session::handle_session_list;
use crate::logging::setup_logging;
use crate::recipe::load_recipe;
use crate::session;
use crate::session::{build_session, SessionBuilderConfig};
use goose_bench::bench_config::BenchRunConfig;
use goose_bench::runners::bench_runner::BenchRunner;
use goose_bench::runners::eval_runner::EvalRunner;
use goose_bench::runners::model_runner::ModelRunner;
use std::io::Read;
use std::path::PathBuf;

#[derive(Parser)]
#[command(author, version, display_name = "", about, long_about = None)]
struct Cli {
    #[command(subcommand)]
    command: Option<Command>,
}

#[derive(Args)]
#[group(required = false, multiple = false)]
struct Identifier {
    #[arg(
        short,
        long,
        value_name = "NAME",
        help = "Name for the chat session (e.g., 'project-x')",
        long_help = "Specify a name for your chat session. When used with --resume, will resume this specific session if it exists."
    )]
    name: Option<String>,

    #[arg(
        short,
        long,
        value_name = "PATH",
        help = "Path for the chat session (e.g., './playground.jsonl')",
        long_help = "Specify a path for your chat session. When used with --resume, will resume this specific session if it exists."
    )]
    path: Option<PathBuf>,
}

fn extract_identifier(identifier: Identifier) -> session::Identifier {
    if let Some(name) = identifier.name {
        session::Identifier::Name(name)
    } else if let Some(path) = identifier.path {
        session::Identifier::Path(path)
    } else {
        unreachable!()
    }
}

#[derive(Subcommand)]
enum SessionCommand {
    #[command(about = "List all available sessions")]
    List {
        #[arg(short, long, help = "List all available sessions")]
        verbose: bool,

        #[arg(
            short,
            long,
            help = "Output format (text, json)",
            default_value = "text"
        )]
        format: String,
    },
}

#[derive(Subcommand)]
pub enum BenchCommand {
    #[command(name = "init-config", about = "Create a new starter-config")]
    InitConfig {
        #[arg(short, long, help = "filename with extension for generated config")]
        name: String,
    },

    #[command(about = "Run all benchmarks from a config")]
    Run {
        #[arg(
            short,
            long,
            help = "A config file generated by the config-init command"
        )]
        config: PathBuf,
    },

    #[command(about = "List all available selectors")]
    Selectors {
        #[arg(
            short,
            long,
            help = "A config file generated by the config-init command"
        )]
        config: Option<PathBuf>,
    },

    #[command(name = "eval-model", about = "Run an eval of model")]
    EvalModel {
        #[arg(short, long, help = "A serialized config file for the model only.")]
        config: String,
    },

    #[command(name = "exec-eval", about = "run a single eval")]
    ExecEval {
        #[arg(short, long, help = "A serialized config file for the eval only.")]
        config: String,
    },
}

#[derive(Subcommand)]
enum RecipeCommand {
    /// Validate a recipe file
    #[command(about = "Validate a recipe file")]
    Validate {
        /// Path to the recipe file to validate
        #[arg(help = "Path to the recipe file to validate")]
        file: String,
    },

    /// Generate a deeplink for a recipe file
    #[command(about = "Generate a deeplink for a recipe file")]
    Deeplink {
        /// Path to the recipe file
        #[arg(help = "Path to the recipe file")]
        file: String,
    },
}

#[derive(Subcommand)]
enum Command {
    /// Configure Goose settings
    #[command(about = "Configure Goose settings")]
    Configure {},

    /// Display Goose configuration information
    #[command(about = "Display Goose information")]
    Info {
        /// Show verbose information including current configuration
        #[arg(short, long, help = "Show verbose information including config.yaml")]
        verbose: bool,
    },

    /// Manage system prompts and behaviors
    #[command(about = "Run one of the mcp servers bundled with goose")]
    Mcp { name: String },

    /// Start or resume interactive chat sessions
    #[command(
        about = "Start or resume interactive chat sessions",
        visible_alias = "s"
    )]
    Session {
        #[command(subcommand)]
        command: Option<SessionCommand>,
        /// Identifier for the chat session
        #[command(flatten)]
        identifier: Option<Identifier>,

        /// Resume a previous session
        #[arg(
            short,
            long,
            help = "Resume a previous session (last used or specified by --name)",
            long_help = "Continue from a previous chat session. If --name or --path is provided, resumes that specific session. Otherwise resumes the last used session."
        )]
        resume: bool,

        /// Enable debug output mode
        #[arg(
            long,
            help = "Enable debug output mode with full content and no truncation",
            long_help = "When enabled, shows complete tool responses without truncation and full paths."
        )]
        debug: bool,

        /// Add stdio extensions with environment variables and commands
        #[arg(
            long = "with-extension",
            value_name = "COMMAND",
            help = "Add stdio extensions (can be specified multiple times)",
            long_help = "Add stdio extensions from full commands with environment variables. Can be specified multiple times. Format: 'ENV1=val1 ENV2=val2 command args...'",
            action = clap::ArgAction::Append
        )]
        extensions: Vec<String>,

        /// Add remote extensions with a URL
        #[arg(
            long = "with-remote-extension",
            value_name = "URL",
            help = "Add remote extensions (can be specified multiple times)",
            long_help = "Add remote extensions from a URL. Can be specified multiple times. Format: 'url...'",
            action = clap::ArgAction::Append
        )]
        remote_extensions: Vec<String>,

        /// Add builtin extensions by name
        #[arg(
            long = "with-builtin",
            value_name = "NAME",
            help = "Add builtin extensions by name (e.g., 'developer' or multiple: 'developer,github')",
            long_help = "Add one or more builtin extensions that are bundled with goose by specifying their names, comma-separated",
            value_delimiter = ','
        )]
        builtins: Vec<String>,
    },

    /// Execute commands from an instruction file
    #[command(about = "Execute commands from an instruction file or stdin")]
    Run {
        /// Path to instruction file containing commands
        #[arg(
            short,
            long,
            value_name = "FILE",
            help = "Path to instruction file containing commands. Use - for stdin.",
            conflicts_with = "input_text",
            conflicts_with = "recipe"
        )]
        instructions: Option<String>,

        /// Input text containing commands
        #[arg(
            short = 't',
            long = "text",
            value_name = "TEXT",
            help = "Input text to provide to Goose directly",
            long_help = "Input text containing commands for Goose. Use this in lieu of the instructions argument.",
            conflicts_with = "instructions",
            conflicts_with = "recipe"
        )]
        input_text: Option<String>,

        /// Path to recipe.yaml file
        #[arg(
            short = None,
            long = "recipe",
            value_name = "FILE",
            help = "Path to recipe.yaml file",
            long_help = "Path to a recipe.yaml file that defines a custom agent configuration",
            conflicts_with = "instructions",
            conflicts_with = "input_text"
        )]
        recipe: Option<String>,

        /// Continue in interactive mode after processing input
        #[arg(
            short = 's',
            long = "interactive",
            help = "Continue in interactive mode after processing initial input"
        )]
        interactive: bool,

        /// Identifier for this run session
        #[command(flatten)]
        identifier: Option<Identifier>,

        /// Resume a previous run
        #[arg(
            short,
            long,
            action = clap::ArgAction::SetTrue,
            help = "Resume from a previous run",
            long_help = "Continue from a previous run, maintaining the execution state and context."
        )]
        resume: bool,

        /// Enable debug output mode
        #[arg(
            long,
            help = "Enable debug output mode with full content and no truncation",
            long_help = "When enabled, shows complete tool responses without truncation and full paths."
        )]
        debug: bool,

        /// Add stdio extensions with environment variables and commands
        #[arg(
            long = "with-extension",
            value_name = "COMMAND",
            help = "Add stdio extensions (can be specified multiple times)",
            long_help = "Add stdio extensions from full commands with environment variables. Can be specified multiple times. Format: 'ENV1=val1 ENV2=val2 command args...'",
            action = clap::ArgAction::Append
        )]
        extensions: Vec<String>,

        /// Add remote extensions
        #[arg(
            long = "with-remote-extension",
            value_name = "URL",
            help = "Add remote extensions (can be specified multiple times)",
            long_help = "Add remote extensions. Can be specified multiple times. Format: 'url...'",
            action = clap::ArgAction::Append
        )]
        remote_extensions: Vec<String>,

        /// Add builtin extensions by name
        #[arg(
            long = "with-builtin",
            value_name = "NAME",
            help = "Add builtin extensions by name (e.g., 'developer' or multiple: 'developer,github')",
            long_help = "Add one or more builtin extensions that are bundled with goose by specifying their names, comma-separated",
            value_delimiter = ','
        )]
        builtins: Vec<String>,
    },

    /// Recipe utilities for validation and deeplinking
    #[command(about = "Recipe utilities for validation and deeplinking")]
    Recipe {
        #[command(subcommand)]
        command: RecipeCommand,
    },

    /// Update the Goose CLI version
    #[command(about = "Update the goose CLI version")]
    Update {
        /// Update to canary version
        #[arg(
            short,
            long,
            help = "Update to canary version",
            long_help = "Update to the latest canary version of the goose CLI, otherwise updates to the latest stable version."
        )]
        canary: bool,

        /// Enforce to re-configure Goose during update
        #[arg(short, long, help = "Enforce to re-configure goose during update")]
        reconfigure: bool,
    },

    Bench {
        #[command(subcommand)]
        cmd: BenchCommand,
    },
}

#[derive(clap::ValueEnum, Clone, Debug)]
enum CliProviderVariant {
    OpenAi,
    Databricks,
    Ollama,
}

struct InputConfig {
    contents: Option<String>,
    extensions_override: Option<Vec<ExtensionConfig>>,
    additional_system_prompt: Option<String>,
}

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

    match cli.command {
        Some(Command::Configure {}) => {
            let _ = handle_configure().await;
            return Ok(());
        }
        Some(Command::Info { verbose }) => {
            handle_info(verbose)?;
            return Ok(());
        }
        Some(Command::Mcp { name }) => {
            let _ = run_server(&name).await;
        }
        Some(Command::Session {
            command,
            identifier,
            resume,
            debug,
            extensions,
            remote_extensions,
            builtins,
        }) => {
            return match command {
                Some(SessionCommand::List { verbose, format }) => {
                    handle_session_list(verbose, format)?;
                    Ok(())
                }
                None => {
                    // Run session command by default
                    let mut session = build_session(SessionBuilderConfig {
                        identifier: identifier.map(extract_identifier),
                        resume,
                        extensions,
                        remote_extensions,
                        builtins,
                        extensions_override: None,
                        additional_system_prompt: None,
                        debug,
                    })
                    .await;
                    setup_logging(
                        session.session_file().file_stem().and_then(|s| s.to_str()),
                        None,
                    )?;
                    let _ = session.interactive(None).await;
                    Ok(())
                }
            };
        }
        Some(Command::Run {
            instructions,
            input_text,
            recipe,
            interactive,
            identifier,
            resume,
            debug,
            extensions,
            remote_extensions,
            builtins,
        }) => {
            let input_config = match (instructions, input_text, recipe) {
                (Some(file), _, _) if file == "-" => {
                    let mut input = String::new();
                    std::io::stdin()
                        .read_to_string(&mut input)
                        .expect("Failed to read from stdin");

                    InputConfig {
                        contents: Some(input),
                        extensions_override: None,
                        additional_system_prompt: None,
                    }
                }
                (Some(file), _, _) => {
                    let contents = std::fs::read_to_string(&file).unwrap_or_else(|err| {
                        eprintln!(
                            "Instruction file not found — did you mean to use goose run --text?\n{}",
                            err
                        );
                        std::process::exit(1);
                    });
                    InputConfig {
                        contents: Some(contents),
                        extensions_override: None,
                        additional_system_prompt: None,
                    }
                }
                (_, Some(text), _) => InputConfig {
                    contents: Some(text),
                    extensions_override: None,
                    additional_system_prompt: None,
                },
                (_, _, Some(file)) => {
                    let recipe = load_recipe(&file, true).unwrap_or_else(|err| {
                        eprintln!("{}: {}", console::style("Error").red().bold(), err);
                        std::process::exit(1);
                    });
                    InputConfig {
                        contents: recipe.prompt,
                        extensions_override: recipe.extensions,
                        additional_system_prompt: Some(recipe.instructions),
                    }
                }
                (None, None, None) => {
                    eprintln!("Error: Must provide either --instructions (-i), --text (-t), or --recipe. Use -i - for stdin.");
                    std::process::exit(1);
                }
            };

            let mut session = build_session(SessionBuilderConfig {
                identifier: identifier.map(extract_identifier),
                resume,
                extensions,
                remote_extensions,
                builtins,
                extensions_override: input_config.extensions_override,
                additional_system_prompt: input_config.additional_system_prompt,
                debug,
            })
            .await;

            setup_logging(
                session.session_file().file_stem().and_then(|s| s.to_str()),
                None,
            )?;

            if interactive {
                let _ = session.interactive(input_config.contents).await;
            } else if let Some(contents) = input_config.contents {
                let _ = session.headless(contents).await;
            } else {
                eprintln!("Error: no text provided for prompt in headless mode");
                std::process::exit(1);
            }

            return Ok(());
        }
        Some(Command::Update {
            canary,
            reconfigure,
        }) => {
            crate::commands::update::update(canary, reconfigure)?;
            return Ok(());
        }
        Some(Command::Bench { cmd }) => {
            match cmd {
                BenchCommand::Selectors { config } => BenchRunner::list_selectors(config)?,
                BenchCommand::InitConfig { name } => BenchRunConfig::default().save(name),
                BenchCommand::Run { config } => BenchRunner::new(config)?.run()?,
                BenchCommand::EvalModel { config } => ModelRunner::from(config)?.run()?,
                BenchCommand::ExecEval { config } => {
                    EvalRunner::from(config)?.run(agent_generator).await?
                }
            }
            return Ok(());
        }
        Some(Command::Recipe { command }) => {
            match command {
                RecipeCommand::Validate { file } => {
                    handle_validate(file)?;
                }
                RecipeCommand::Deeplink { file } => {
                    handle_deeplink(file)?;
                }
            }
            return Ok(());
        }
        None => {
            return if !Config::global().exists() {
                let _ = handle_configure().await;
                Ok(())
            } else {
                // Run session command by default
                let mut session = build_session(SessionBuilderConfig::default()).await;
                setup_logging(
                    session.session_file().file_stem().and_then(|s| s.to_str()),
                    None,
                )?;
                if let Err(e) = session.interactive(None).await {
                    eprintln!("Session ended with error: {}", e);
                }
                Ok(())
            };
        }
    }
    Ok(())
}