use std::path::PathBuf;

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

use clap_complete::Shell;

use conjure_cp::settings::{

    DEFAULT_MINION_DISCRETE_THRESHOLD, Parser as InputParser, QuantifiedExpander, Rewriter,

    SolverFamily,

};

use crate::{pretty, solve, test_solve};

pub(crate) const DEBUG_HELP_HEADING: Option<&str> = Some("Debug");

pub(crate) const LOGGING_HELP_HEADING: Option<&str> = Some("Logging & Output");

pub(crate) const CONFIGURATION_HELP_HEADING: Option<&str> = Some("Configuration");

pub(crate) const OPTIMISATIONS_HELP_HEADING: Option<&str> = Some("Optimisations");

/// All subcommands of conjure-oxide

#[derive(Clone, Debug, Subcommand)]

pub enum Command {

    /// Solve a model

    Solve(solve::Args),

    /// Print the JSON info file schema

    PrintJsonSchema,

    /// Tests whether the Essence model is solvable with Conjure Oxide, and whether it gets the

    /// same solutions as Conjure.

    ///

    /// Return-code will be 0 if the solutions match, 1 if they don't, and >1 on crash.

    TestSolve(test_solve::Args),

    /// Generate a completion script for the shell provided

    Completion(CompletionArgs),

    Pretty(pretty::Args),

    // Run the language server

    ServerLSP,

}

/// Global command line arguments.

#[derive(Clone, Debug, Parser)]

#[command(

    author,

    about = "Conjure Oxide: Automated Constraints Modelling Toolkit",

    before_help = "Full documentation can be found online at: https://conjure-cp.github.io/conjure-oxide"

)]

pub struct Cli {

    #[command(subcommand)]

    pub subcommand: Command,

    #[command(flatten)]

    pub global_args: GlobalArgs,

    /// Print version

    #[arg(long = "version", short = 'V')]

    pub version: bool,

}

#[derive(Debug, Clone, Args)]

pub struct GlobalArgs {

    /// Extra rule sets to enable

    #[arg(long, value_name = "EXTRA_RULE_SETS", global = true)]

    pub extra_rule_sets: Vec<String>,

    /// Log verbosely

    #[arg(long, short = 'v', help = "Log verbosely to stderr", global = true, help_heading = LOGGING_HELP_HEADING)]

    pub verbose: bool,

    // --no-x flag disables --x flag : https://jwodder.github.io/kbits/posts/clap-bool-negate/

    /// Check for multiple equally applicable rules, exiting if any are found.

    ///

    /// Only compatible with the default rewriter.

    #[arg(

        long,

        overrides_with = "_no_check_equally_applicable_rules",

        default_value_t = false,

        global = true,

        help_heading= DEBUG_HELP_HEADING

    )]

    pub check_equally_applicable_rules: bool,

    /// Output file for the human readable rule trace.

    #[arg(long, global = true, help_heading=LOGGING_HELP_HEADING)]

    pub rule_trace: Option<PathBuf>,

    /// Output file for verbose rule-attempt trace in CSV format.

    ///

    /// Each row includes: elapsed_s, rule_level, rule_name, rule_set, status, expression.

    #[arg(long, global = true, help_heading=LOGGING_HELP_HEADING)]

    pub rule_trace_verbose: Option<PathBuf>,

    /// Do not check for multiple equally applicable rules [default].

    ///

    /// Only compatible with the default rewriter.

    #[arg(long, global = true, help_heading = DEBUG_HELP_HEADING)]

    pub _no_check_equally_applicable_rules: bool,

    /// Which parser to use.

    ///

    /// Possible values: `tree-sitter`, `via-conjure`.

    #[arg(

        long,

        default_value_t = InputParser::ViaConjure,

        value_parser = parse_parser,

        global = true,

        help_heading = CONFIGURATION_HELP_HEADING

    )]

    pub parser: InputParser,

    /// Which rewriter to use.

    ///

    /// Possible values: `naive`, `morph`.

    #[arg(long, default_value_t = Rewriter::Naive, value_parser = parse_rewriter, global = true, help_heading = CONFIGURATION_HELP_HEADING)]

    pub rewriter: Rewriter,

    /// Which strategy to use for expanding quantified variables in comprehensions.

    ///

    /// Possible values: `native`, `via-solver`, `via-solver-ac`.

    #[arg(

        long,

        default_value_t = QuantifiedExpander::Native,

        value_parser = parse_comprehension_expander,

        global = true,

        help_heading = CONFIGURATION_HELP_HEADING

    )]

    pub comprehension_expander: QuantifiedExpander,

    /// Solver family to use.

    ///

    /// Possible values: `minion`, `sat`, `sat-log`, `sat-direct`, `sat-order`;

    /// with `smt` feature: `smt` and `smt-<ints>-<matrices>[-nodiscrete]`

    /// where `<ints>` is `lia` or `bv`, and `<matrices>` is `arrays` or `atomic`.

    #[arg(

        long,

        value_name = "SOLVER",

        value_parser = parse_solver_family,

        default_value = "minion",

        short = 's',

        global = true,

        help_heading = CONFIGURATION_HELP_HEADING

    )]

    pub solver: SolverFamily,

    /// Int-domain size threshold for using Minion `DISCRETE` variables.

    ///

    /// If an int domain has size <= this value, Conjure Oxide emits `DISCRETE`; otherwise `BOUND`.

    #[arg(

        long,

        default_value_t = DEFAULT_MINION_DISCRETE_THRESHOLD,

        global = true,

        help_heading = CONFIGURATION_HELP_HEADING

    )]

    pub minion_discrete_threshold: usize,

    /// Save a solver input file to <filename>.

    ///

    /// This input file will be in a format compatible by the command-line

    /// interface of the selected solver. For example, when the solver is Minion,

    /// a valid .minion file will be output.

    ///

    /// This file is for informational purposes only; the results of running

    /// this file cannot be used by Conjure Oxide in any way.

    #[arg(long,global=true, value_names=["filename"], next_line_help=true, help_heading=LOGGING_HELP_HEADING)]

    pub save_solver_input_file: Option<PathBuf>,

    /// Stop the solver after the given timeout.

    ///

    /// Currently only SMT supports this feature.

    #[arg(long, global = true, help_heading = OPTIMISATIONS_HELP_HEADING)]

    pub solver_timeout: Option<humantime::Duration>,

    /// Generate log files

    #[arg(long, default_value_t = false, global = true, help_heading = LOGGING_HELP_HEADING)]

    pub log: bool,

    /// Output file for conjure-oxide's text logs

    #[arg(long, value_name = "LOGFILE", global = true, help_heading = LOGGING_HELP_HEADING)]

    pub logfile: Option<PathBuf>,

    /// Output file for conjure-oxide's json logs

    #[arg(long, value_name = "JSON LOGFILE", global = true, help_heading = LOGGING_HELP_HEADING)]

    pub logfile_json: Option<PathBuf>,

}

#[derive(Debug, Clone, Args)]

pub struct CompletionArgs {

    /// Shell type for which to generate the completion script

    #[arg(value_enum)]

    pub shell: Shell,

}

#[derive(Debug, Clone, Copy, clap::ValueEnum)]

pub enum ShellTypes {

    Bash,

    Zsh,

    Fish,

    PowerShell,

    Elvish,

}