use anyhow::{Result, bail};
use clap::Parser;
use colored::Colorize;
use dialoguer::{Confirm, Input, Select};
use semver::Version;
use std::path::PathBuf;

use crate::config::{Language, manager::ConfigManager};
use crate::generator::ContentGenerator;
use crate::git::tag::{
    ConfigVersion, TagBuilder, VersionBump, bump_version, get_latest_version,
    read_project_versions, suggest_version_bump,
};
use crate::git::{GitRepo, find_repo};
use crate::i18n::Messages;
use crate::utils::{print_progress, print_success, print_warning};

/// Generate and create Git tags
#[derive(Parser)]
pub struct TagCommand {
    /// Tag name
    #[arg(short, long)]
    name: Option<String>,

    /// Semantic version bump
    #[arg(short, long, value_name = "TYPE")]
    bump: Option<String>,

    /// Tag message
    #[arg(short, long)]
    message: Option<String>,

    /// Generate message with AI
    #[arg(short, long)]
    generate: bool,

    /// Sign the tag
    #[arg(short = 'S', long)]
    sign: bool,

    /// Create lightweight tag (no annotation)
    #[arg(short, long)]
    lightweight: bool,

    /// Force overwrite existing tag
    #[arg(short, long)]
    force: bool,

    /// Push tag to remote after creation
    #[arg(short, long)]
    push: bool,

    /// Remote to push to
    #[arg(short, long, default_value = "origin")]
    remote: String,

    /// Dry run
    #[arg(long)]
    dry_run: bool,

    /// Enable thinking mode for this tag (override config)
    #[arg(short = 't', long)]
    think: bool,

    /// Skip interactive prompts only (generation behavior unchanged)
    #[arg(short = 'y', long)]
    yes: bool,

    /// Auto-detect version from project config (Cargo.toml/pyproject.toml),
    /// falling back to commit analysis with confirmation. Mutually exclusive with --bump.
    #[arg(short = 'A', long, conflicts_with = "bump")]
    auto: bool,
}

impl TagCommand {
    pub async fn execute(&self, config_path: Option<PathBuf>) -> Result<()> {
        let repo = find_repo(std::env::current_dir()?.as_path())?;
        let manager = if let Some(ref path) = config_path {
            ConfigManager::with_path(path)?
        } else {
            ConfigManager::new()?
        };
        let config = manager.config();
        let language = manager.get_language().unwrap_or(Language::English);
        let messages = Messages::new(language);

        // Determine tag name
        let tag_name = if let Some(name) = &self.name {
            name.clone()
        } else if self.auto {
            self.auto_detect_version(&repo, &config.tag.version_prefix, &messages)
                .await?
        } else if let Some(bump_str) = &self.bump {
            // Calculate bumped version
            let prefix = &config.tag.version_prefix;
            let latest =
                get_latest_version(&repo, prefix)?.unwrap_or_else(|| Version::new(0, 0, 0));

            let bump = VersionBump::from_str(bump_str)?;
            let new_version = bump_version(&latest, bump, None);

            format!("{}{}", prefix, new_version)
        } else {
            // Interactive mode
            self.select_version_interactive(&repo, &config.tag.version_prefix, &messages)
                .await?
        };

        // Validate tag name (if it looks like a version)
        if tag_name.starts_with('v')
            || tag_name
                .chars()
                .next()
                .map(|c| c.is_ascii_digit())
                .unwrap_or(false)
        {
            let version_str = tag_name.trim_start_matches('v');
            if let Err(e) = crate::utils::validators::validate_semver(version_str) {
                print_warning(&format!("{}: {}", messages.warning(), e));

                if !self.yes {
                    let proceed = Confirm::new()
                        .with_prompt(messages.proceed_invalid_tag_name())
                        .default(true)
                        .interact()?;

                    if !proceed {
                        bail!("{}", messages.tag_cancelled());
                    }
                }
            }
        }

        // Generate or get tag message
        let message = if self.lightweight {
            None
        } else if let Some(msg) = &self.message {
            Some(msg.clone())
        } else if self.generate || config.tag.auto_generate {
            Some(
                self.generate_tag_message(&repo, &tag_name, &messages)
                    .await?,
            )
        } else if !self.yes {
            Some(self.input_message_interactive(&tag_name, &messages)?)
        } else {
            Some(messages.release_default(&tag_name))
        };

        // Show preview
        println!("\n{}", "─".repeat(60));
        println!("{}", messages.tag_preview().bold());
        println!("{}", "─".repeat(60));
        println!("Name:  {}", tag_name.cyan());
        if let Some(ref msg) = message {
            println!("Message:\n{}", msg);
        } else {
            println!("Type:  {}", "lightweight".yellow());
        }
        println!("{}", "─".repeat(60));

        if !self.yes {
            let confirm = Confirm::new()
                .with_prompt(messages.create_tag())
                .default(true)
                .interact()?;

            if !confirm {
                print_warning(messages.tag_cancelled());
                return Ok(());
            }
        }

        if self.dry_run {
            println!("\n{}", messages.dry_run_tag_not_created().yellow());
            return Ok(());
        }

        let builder = TagBuilder::new()
            .name(&tag_name)
            .message_opt(message)
            .annotate(!self.lightweight)
            .sign(self.sign)
            .force(self.force);

        builder.execute(&repo)?;

        print_success(&format!("{} {}", messages.tag_created(), tag_name.cyan()));

        // Push if requested or ask user
        if self.push {
            print_progress(&messages.pushing_tag(&self.remote));
            repo.push(&self.remote, &format!("refs/tags/{}", tag_name))?;
            print_success(&messages.pushed_tag(&self.remote));
        } else if !self.yes && !self.dry_run {
            let should_push = Confirm::new()
                .with_prompt(messages.push_after_tag())
                .default(false)
                .interact()?;

            if should_push {
                print_progress(&messages.pushing_tag(&self.remote));
                repo.push(&self.remote, &format!("refs/tags/{}", tag_name))?;
                print_success(&messages.pushed_tag(&self.remote));
            }
        }

        Ok(())
    }

    async fn select_version_interactive(
        &self,
        repo: &GitRepo,
        prefix: &str,
        messages: &Messages,
    ) -> Result<String> {
        loop {
            let latest = get_latest_version(repo, prefix)?;

            println!("\n{}", messages.version_selection().bold());

            if let Some(ref version) = latest {
                println!("{} {}{}", messages.latest_version(), prefix, version);
            } else {
                println!("{}", messages.no_existing_version_tags());
            }

            let options = vec![
                messages.auto_detect_bump(),
                messages.bump_major_version(),
                messages.bump_minor_version(),
                messages.bump_patch_version(),
                messages.enter_custom_version(),
                messages.enter_custom_tag_name(),
            ];

            let selection = Select::new()
                .with_prompt(messages.select_option())
                .items(&options)
                .default(0)
                .interact()?;

            match selection {
                0 => {
                    // Auto-detect
                    let commits = repo.get_commits(50)?;
                    let bump = suggest_version_bump(&commits);
                    let version = latest
                        .as_ref()
                        .map(|v| bump_version(v, bump, None))
                        .unwrap_or_else(|| Version::new(0, 1, 0));

                    println!(
                        "{} {:?} → {}{}",
                        messages.suggested_bump(),
                        bump,
                        prefix,
                        version
                    );

                    let confirm = Confirm::new()
                        .with_prompt(messages.use_this_version())
                        .default(true)
                        .interact()?;

                    if confirm {
                        return Ok(format!("{}{}", prefix, version));
                    }
                    // User rejected, continue the loop
                }
                1 => {
                    let version = latest
                        .as_ref()
                        .map(|v| bump_version(v, VersionBump::Major, None))
                        .unwrap_or_else(|| Version::new(1, 0, 0));
                    return Ok(format!("{}{}", prefix, version));
                }
                2 => {
                    let version = latest
                        .as_ref()
                        .map(|v| bump_version(v, VersionBump::Minor, None))
                        .unwrap_or_else(|| Version::new(0, 1, 0));
                    return Ok(format!("{}{}", prefix, version));
                }
                3 => {
                    let version = latest
                        .as_ref()
                        .map(|v| bump_version(v, VersionBump::Patch, None))
                        .unwrap_or_else(|| Version::new(0, 0, 1));
                    return Ok(format!("{}{}", prefix, version));
                }
                4 => {
                    let input: String = Input::new()
                        .with_prompt(messages.enter_version())
                        .interact_text()?;
                    let version = Version::parse(&input)?;
                    return Ok(format!("{}{}", prefix, version));
                }
                5 => {
                    let input: String = Input::new()
                        .with_prompt(messages.enter_tag_name())
                        .interact_text()?;
                    return Ok(input);
                }
                _ => unreachable!(),
            }
        }
    }

    async fn generate_tag_message(
        &self,
        repo: &GitRepo,
        version: &str,
        messages: &Messages,
    ) -> Result<String> {
        let manager = ConfigManager::new()?;
        let language = manager.get_language().unwrap_or(Language::English);

        let tags = repo.get_tags()?;
        let commits = if let Some(latest_tag) = tags.first() {
            repo.get_commits_between(&latest_tag.name, "HEAD")?
        } else {
            repo.get_commits(50)?
        };

        if commits.is_empty() {
            return Ok(messages.release_default(version));
        }

        let generator = ContentGenerator::new_with_think(&manager, self.think, None).await?;
        let spinner = crate::utils::Spinner::start(&messages.ai_generating_tag(commits.len()));
        let result = generator
            .generate_tag_message(version, &commits, language)
            .await;
        spinner.finish_clear();
        result
    }

    async fn auto_detect_version(
        &self,
        repo: &GitRepo,
        prefix: &str,
        messages: &Messages,
    ) -> Result<String> {
        let project_dir = std::env::current_dir()?;

        // 1. Try reading from project config files
        let config_versions = read_project_versions(&project_dir);

        if !config_versions.is_empty() {
            if config_versions.len() == 1 {
                let cv = &config_versions[0];
                let tag_name = format!("{}{}", prefix, cv.version);
                println!(
                    "{} ({}): {}",
                    messages.found_version_in(),
                    cv.source,
                    tag_name.cyan()
                );
                return Ok(tag_name);
            }

            // Multiple config files: let user choose
            return self.select_config_version(&config_versions, prefix, messages);
        }

        // 2. Fall back to commit analysis
        println!("{}", messages.auto_detect_bump());
        let commits = repo.get_commits(50)?;
        let bump = suggest_version_bump(&commits);
        let latest = get_latest_version(repo, prefix)?.unwrap_or_else(|| Version::new(0, 0, 0));
        let version = bump_version(&latest, bump, None);
        let tag_name = format!("{}{}", prefix, version);

        println!(
            "{} {:?} → {}",
            messages.suggested_bump(),
            bump,
            tag_name.cyan()
        );

        if !self.yes {
            let confirm = Confirm::new()
                .with_prompt(messages.use_this_version())
                .default(true)
                .interact()?;

            if !confirm {
                // Fall through to interactive version selection
                return self
                    .select_version_interactive(repo, prefix, messages)
                    .await;
            }
        }

        Ok(tag_name)
    }

    fn select_config_version(
        &self,
        config_versions: &[ConfigVersion],
        prefix: &str,
        messages: &Messages,
    ) -> Result<String> {
        println!("\n{}", messages.found_multiple_versions().bold());

        let items: Vec<String> = config_versions
            .iter()
            .map(|cv| format!("{} → {}{}", cv.source, prefix, cv.version))
            .collect();

        let selection = Select::new()
            .with_prompt(messages.select_version_to_use())
            .items(&items)
            .default(0)
            .interact()?;

        let cv = &config_versions[selection];
        Ok(format!("{}{}", prefix, cv.version))
    }

    fn input_message_interactive(&self, version: &str, messages: &Messages) -> Result<String> {
        let default_msg = messages.release_default(version);

        let use_editor = Confirm::new()
            .with_prompt(messages.open_editor())
            .default(false)
            .interact()?;

        if use_editor {
            crate::utils::editor::edit_content(&default_msg)
        } else {
            Ok(Input::new()
                .with_prompt(messages.tag_message())
                .default(default_msg)
                .interact_text()?)
        }
    }
}

// Helper trait
trait TagBuilderExt {
    fn message_opt(self, message: Option<String>) -> Self;
}

impl TagBuilderExt for TagBuilder {
    fn message_opt(self, message: Option<String>) -> Self {
        if let Some(m) = message {
            self.message(m)
        } else {
            self
        }
    }
}