//! `sm121 promote` — move a recipe across recipe repos (git mv, decomposed
//! into per-repo commit + push).
//!
//! The target is updated FIRST (copy in + commit + push); only then is the
//! recipe removed from the source. A failure in between therefore leaves
//! the recipe duplicated (safe under the priority semantics — the source
//! repo shadows the target) and never deleted. `--dry-run` (the global
//! `-d`) prints the exact commands; `--apply` runs them.

use crate::config::{Config, RecipeRepo};
use crate::recipe_repos::{cache_base, git, repo_cache_dir, sync_repo};
use anyhow::{Context, Result};
use std::path::{Path, PathBuf};

/// One executable step of a promotion plan.
#[derive(Debug, Clone)]
pub struct Step {
    /// `"target"` (the repo the recipe moves INTO) or `"source"`.
    pub side: &'static str,
    /// Human-readable form (what `--dry-run` prints).
    pub description: String,
    /// What `execute` runs.
    pub run: Run,
}

#[derive(Debug, Clone)]
pub enum Run {
    /// `cp -a` the recipe dir between the two checkouts (a git mv across
    /// repos has no single git command).
    Copy { from: PathBuf, to: PathBuf },
    /// `git -C <cwd> <args…>`.
    Git { cwd: PathBuf, args: Vec<String> },
    /// `git -C <cwd> push <url> <branch>` (the URL may carry the token).
    Push {
        cwd: PathBuf,
        url: String,
        branch: String,
    },
}

/// The full promotion plan (target steps first, then source steps).
#[derive(Debug, Clone)]
pub struct PromotePlan {
    pub recipe: String,
    pub from_url: String,
    pub to_url: String,
    pub from_checkout: PathBuf,
    pub to_checkout: PathBuf,
    pub steps: Vec<Step>,
}

/// Find a configured `[[recipe_repos]]` entry by exact URL.
fn find_repo<'a>(config: &'a Config, url: &str) -> Result<&'a RecipeRepo> {
    config
        .recipe_repos
        .iter()
        .find(|r| r.url == url)
        .with_context(
            || fluent_i18n::t!("promote-repo-not-configured", { "url" => url.to_string() }),
        )
}

/// The checkout dir of a repo, synced on demand (a promote must not plan
/// against a missing checkout). With `sync_missing = false` (dry-run) a
/// missing checkout is an error instead of a side-effecting clone.
fn ensure_checkout(repo: &RecipeRepo, sync_missing: bool) -> Result<PathBuf> {
    let dir = repo_cache_dir(&cache_base(), &repo.url);
    if !dir.join(".git").is_dir() {
        if !sync_missing {
            anyhow::bail!(fluent_i18n::t!(
                "promote-checkout-missing",
                { "url" => &repo.url }
            ));
        }
        sync_repo(repo).with_context(
            || fluent_i18n::t!("promote-checkout-sync-fail", { "url" => &repo.url }),
        )?;
    }
    Ok(dir)
}

fn branch_of(checkout: &Path) -> Result<String> {
    let b = git(&[
        "-C",
        &checkout.display().to_string(),
        "rev-parse",
        "--abbrev-ref",
        "HEAD",
    ])?;
    if b.is_empty() || b == "HEAD" {
        anyhow::bail!(fluent_i18n::t!(
            "promote-detached-head",
            { "path" => checkout.display().to_string() }
        ));
    }
    Ok(b)
}

fn shq(s: &str) -> String {
    format!("'{}'", s.replace('\'', "'\\''"))
}

/// Build the promotion plan: validate the move (the recipe must exist in
/// the source and NOT in the target — no silent overwrite), then the
/// target-side copy + commit + push, then the source-side remove + commit
/// + push.
pub fn plan(
    config: &Config,
    recipe: &str,
    from_url: &str,
    to_url: &str,
    sync_missing: bool,
) -> Result<PromotePlan> {
    if from_url == to_url {
        anyhow::bail!(fluent_i18n::t!("promote-same-repo"));
    }
    let from = find_repo(config, from_url)?;
    let to = find_repo(config, to_url)?;
    let from_dir = ensure_checkout(from, sync_missing)?;
    let to_dir = ensure_checkout(to, sync_missing)?;

    let from_recipe = from_dir.join("recipes").join(recipe);
    let to_recipe = to_dir.join("recipes").join(recipe);
    if !from_recipe.is_dir() {
        anyhow::bail!(fluent_i18n::t!(
            "promote-recipe-not-in-source",
            { "recipe" => recipe.to_string(), "path" => from_dir.display().to_string() }
        ));
    }
    if to_recipe.exists() {
        anyhow::bail!(fluent_i18n::t!(
            "promote-recipe-in-target",
            { "recipe" => recipe.to_string() }
        ));
    }

    let from_branch = branch_of(&from_dir)?;
    let to_branch = branch_of(&to_dir)?;

    let mut steps = Vec::new();
    steps.push(Step {
        side: "target",
        description: format!(
            "cp -a {} {}",
            shq(&from_recipe.display().to_string()),
            shq(&to_recipe.display().to_string())
        ),
        run: Run::Copy {
            from: from_recipe.clone(),
            to: to_recipe.clone(),
        },
    });
    steps.push(Step {
        side: "target",
        description: format!("git -C {} add recipes/{}", to_dir.display(), recipe),
        run: Run::Git {
            cwd: to_dir.clone(),
            args: vec!["add".into(), format!("recipes/{recipe}")],
        },
    });
    let to_commit_msg = format!("promote {recipe}: add from {from_url}");
    steps.push(Step {
        side: "target",
        description: format!(
            "git -C {} commit -m {}",
            to_dir.display(),
            shq(&to_commit_msg)
        ),
        run: Run::Git {
            cwd: to_dir.clone(),
            args: vec!["commit".into(), "-m".into(), to_commit_msg],
        },
    });
    steps.push(Step {
        side: "target",
        description: format!("git -C {} push {} {}", to_dir.display(), to.url, to_branch),
        run: Run::Push {
            cwd: to_dir.clone(),
            url: crate::recipe_repos::push_url(to),
            branch: to_branch.clone(),
        },
    });
    steps.push(Step {
        side: "source",
        description: format!("git -C {} rm -r recipes/{}", from_dir.display(), recipe),
        run: Run::Git {
            cwd: from_dir.clone(),
            args: vec!["rm".into(), "-r".into(), format!("recipes/{recipe}")],
        },
    });
    let from_commit_msg = format!("promote {recipe}: remove (promoted to {to_url})");
    steps.push(Step {
        side: "source",
        description: format!(
            "git -C {} commit -m {}",
            from_dir.display(),
            shq(&from_commit_msg)
        ),
        run: Run::Git {
            cwd: from_dir.clone(),
            args: vec!["commit".into(), "-m".into(), from_commit_msg],
        },
    });
    steps.push(Step {
        side: "source",
        description: format!(
            "git -C {} push {} {}",
            from_dir.display(),
            from.url,
            from_branch
        ),
        run: Run::Push {
            cwd: from_dir.clone(),
            url: crate::recipe_repos::push_url(from),
            branch: from_branch,
        },
    });

    Ok(PromotePlan {
        recipe: recipe.to_string(),
        from_url: from_url.to_string(),
        to_url: to_url.to_string(),
        from_checkout: from_dir,
        to_checkout: to_dir,
        steps,
    })
}

/// Run every step of the plan (in order; a failure stops the promote,
/// leaving the recipe at least duplicated, never deleted).
pub fn execute(plan: &PromotePlan) -> Result<()> {
    for step in &plan.steps {
        match &step.run {
            Run::Copy { from, to } => {
                std::fs::create_dir_all(
                    to.parent()
                        .context(fluent_i18n::t!("promote-target-dir-context"))?,
                )?;
                let out = std::process::Command::new("cp")
                    .arg("-a")
                    .arg(from)
                    .arg(to)
                    .output()
                    .context(fluent_i18n::t!("promote-cp-context"))?;
                if !out.status.success() {
                    anyhow::bail!(fluent_i18n::t!(
                        "promote-cp-failed",
                        { "err" => String::from_utf8_lossy(&out.stderr).trim().to_string() }
                    ));
                }
            }
            Run::Git { cwd, args } => {
                let cwd_s = cwd.display().to_string();
                let mut a: Vec<&str> = vec!["-C", &cwd_s];
                a.extend(args.iter().map(String::as_str));
                git(&a)?;
            }
            Run::Push { cwd, url, branch } => {
                git(&["-C", &cwd.display().to_string(), "push", url, branch])?;
            }
        }
        println!(
            "{}",
            fluent_i18n::t!("promote-step-line", { "side" => step.side, "description" => &step.description })
        );
    }
    Ok(())
}

/// `sm121 promote <recipe> --from <url> --to <url> [--apply]` dispatch:
/// plan, print (default / `-d`), execute (`--apply`).
pub fn run(
    config: &Config,
    recipe: &str,
    from_url: &str,
    to_url: &str,
    apply: bool,
    dry_run: bool,
) -> Result<()> {
    let plan = plan(config, recipe, from_url, to_url, !dry_run)?;
    if apply && !dry_run {
        println!(
            "{}",
            fluent_i18n::t!("promote-run-start", { "recipe" => &plan.recipe, "from" => &plan.from_url, "to" => &plan.to_url, "count" => plan.steps.len() })
        );
        println!(
            "{}",
            fluent_i18n::t!("promote-source-checkout", { "path" => plan.from_checkout.display().to_string() })
        );
        println!(
            "{}",
            fluent_i18n::t!("promote-target-checkout", { "path" => plan.to_checkout.display().to_string() })
        );
        execute(&plan)?;
        println!(
            "{}",
            fluent_i18n::t!("promote-done", { "recipe" => &plan.recipe })
        );
        return Ok(());
    }
    println!(
        "{}",
        fluent_i18n::t!("promote-dry-head", { "recipe" => &plan.recipe, "from" => &plan.from_url, "to" => &plan.to_url })
    );
    println!(
        "{}",
        fluent_i18n::t!("promote-source-checkout", { "path" => plan.from_checkout.display().to_string() })
    );
    println!(
        "{}",
        fluent_i18n::t!("promote-target-checkout", { "path" => plan.to_checkout.display().to_string() })
    );
    for step in &plan.steps {
        println!(
            "{}",
            fluent_i18n::t!("promote-step-line", { "side" => step.side, "description" => &step.description })
        );
    }
    if apply {
        println!("{}", fluent_i18n::t!("promote-dry-suppressed"));
    }
    println!("{}", fluent_i18n::t!("promote-run-apply-hint"));
    Ok(())
}

#[cfg(test)]
#[path = "promote_tests.rs"]
mod tests;