use crate::config::SiteConfig;
use crate::logs::{BuildExitStatus, BuildLogMeta};
use crate::state::BuildEntry;
use crate::{build, cleanup, git, hook, logs, publish, repo_config, state};
use anyhow::Result;
use log::{error, info, warn};
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::time::{Duration, Instant, SystemTime};

/// Result of a successful pipeline run.
pub struct PipelineResult {
    pub build_dir: PathBuf,
    pub log_file: PathBuf,
    pub timestamp: String,
    pub duration: Duration,
}

/// Run the complete build pipeline: git sync → build → publish.
///
/// This is the core pipeline logic shared by both the HTTP server and the CLI
/// `run` command. The server wraps this with `BuildGuard` for concurrency
/// control; the CLI calls it directly.
///
/// # Errors
///
/// Returns an error on git sync failure, config load failure, build failure,
/// or publish failure. Post-deploy hook and cleanup failures are non-fatal
/// (logged as warnings).
#[allow(clippy::too_many_arguments, clippy::too_many_lines)]
pub async fn run_build(
    site_name: &str,
    site: &SiteConfig,
    base_dir: &Path,
    log_dir: &Path,
    container_runtime: &str,
    max_builds_to_keep: u32,
    git_timeout: Duration,
    verbose: bool,
) -> Result<PipelineResult> {
    let now = SystemTime::now();
    let timestamp = crate::time::format_build_timestamp(now);
    let start_time = Instant::now();
    let started_at = crate::time::format_rfc3339(now);
    let log_path_str = log_dir
        .join(site_name)
        .join(format!("{timestamp}.log"))
        .to_string_lossy()
        .to_string();

    // Write "building" state
    state::push_build(
        base_dir,
        site_name,
        BuildEntry {
            status: "building".to_owned(),
            timestamp: timestamp.clone(),
            started_at: started_at.clone(),
            git_commit: String::new(),
            duration: String::new(),
            log: log_path_str.clone(),
        },
    )
    .await;

    let clone_dir = base_dir.join("clones").join(site_name);

    // 1. Sync git repository
    info!("[{site_name}] syncing repository");
    if let Err(e) = git::sync_repo(
        &site.repo_url,
        &site.branch,
        &clone_dir,
        git_timeout,
        site.git_depth.unwrap_or(git::GIT_DEPTH_DEFAULT),
    )
    .await
    {
        error!("[{site_name}] git sync failed: {e}");
        let duration = start_time.elapsed();
        save_build_log_for_error(
            log_dir,
            site_name,
            &timestamp,
            start_time,
            None,
            "git-sync",
            &e.to_string(),
        )
        .await;
        update_final_state(base_dir, site_name, "failed", "", duration).await;
        return Err(e.context("git sync failed"));
    }

    // Get git commit hash for logging
    let git_commit = logs::get_git_commit(&clone_dir).await;

    // 2. Load repo config (witryna.yaml) with overrides from witryna.toml
    let repo_config = match repo_config::RepoConfig::load_with_overrides(
        &clone_dir,
        &site.build_overrides,
        site.config_file.as_deref(),
    )
    .await
    {
        Ok(config) => config,
        Err(e) => {
            error!("[{site_name}] failed to load repo config: {e}");
            let duration = start_time.elapsed();
            save_build_log_for_error(
                log_dir,
                site_name,
                &timestamp,
                start_time,
                git_commit.clone(),
                "config-load",
                &e.to_string(),
            )
            .await;
            update_final_state(
                base_dir,
                site_name,
                "failed",
                git_commit.as_deref().unwrap_or(""),
                duration,
            )
            .await;
            return Err(e.context("failed to load repo config"));
        }
    };

    // 3. Prepare cache volumes
    let cache_volumes = match &site.cache_dirs {
        Some(dirs) if !dirs.is_empty() => {
            let mut volumes = Vec::with_capacity(dirs.len());
            for dir in dirs {
                let sanitized = crate::config::sanitize_cache_dir_name(dir);
                let host_path = base_dir.join("cache").join(site_name).join(&sanitized);
                if let Err(e) = tokio::fs::create_dir_all(&host_path).await {
                    error!(
                        "[{site_name}] failed to create cache directory: path={} {e}",
                        host_path.display()
                    );
                    anyhow::bail!("failed to create cache directory: {e}");
                }
                volumes.push((dir.clone(), host_path));
            }
            let mount_list: Vec<_> = volumes
                .iter()
                .map(|(c, h)| format!("{}:{}", h.display(), c))
                .collect();
            info!("[{site_name}] mounting cache volumes: {mount_list:?}");
            volumes
        }
        _ => Vec::new(),
    };

    // 4. Execute build — stream output to temp files
    let site_log_dir = log_dir.join(site_name);
    if let Err(e) = tokio::fs::create_dir_all(&site_log_dir).await {
        error!("[{site_name}] failed to create log directory: {e}");
        anyhow::bail!("failed to create log directory: {e}");
    }
    let stdout_tmp = site_log_dir.join(format!("{timestamp}-stdout.tmp"));
    let stderr_tmp = site_log_dir.join(format!("{timestamp}-stderr.tmp"));

    let env = site.env.clone().unwrap_or_default();
    let timeout = site.build_timeout.unwrap_or(build::BUILD_TIMEOUT_DEFAULT);
    let options = build::ContainerOptions {
        memory: site.container_memory.clone(),
        cpus: site.container_cpus,
        pids_limit: site.container_pids_limit,
        network: site.container_network.clone(),
        workdir: site.container_workdir.clone(),
    };
    info!(
        "[{site_name}] running container build: image={}",
        repo_config.image
    );
    let build_result = Box::pin(build::execute(
        container_runtime,
        &clone_dir,
        &repo_config,
        &cache_volumes,
        &env,
        &options,
        &stdout_tmp,
        &stderr_tmp,
        timeout,
        verbose,
    ))
    .await;

    // Determine exit status and extract temp file paths
    let (exit_status, build_stdout_file, build_stderr_file, build_duration) = match &build_result {
        Ok(result) => (
            BuildExitStatus::Success,
            result.stdout_file.clone(),
            result.stderr_file.clone(),
            result.duration,
        ),
        Err(e) => e.downcast_ref::<build::BuildFailure>().map_or_else(
            || {
                (
                    BuildExitStatus::Failed {
                        exit_code: None,
                        error: e.to_string(),
                    },
                    stdout_tmp.clone(),
                    stderr_tmp.clone(),
                    start_time.elapsed(),
                )
            },
            |failure| {
                (
                    BuildExitStatus::Failed {
                        exit_code: Some(failure.exit_code),
                        error: failure.to_string(),
                    },
                    failure.stdout_file.clone(),
                    failure.stderr_file.clone(),
                    failure.duration,
                )
            },
        ),
    };

    // Ensure temp files exist for save_build_log (spawn errors may not create them)
    if !build_stdout_file.exists() {
        let _ = tokio::fs::File::create(&build_stdout_file).await;
    }
    if !build_stderr_file.exists() {
        let _ = tokio::fs::File::create(&build_stderr_file).await;
    }

    // Save build log (always, success or failure) — streams from temp files
    let meta = BuildLogMeta {
        site_name: site_name.to_owned(),
        timestamp: timestamp.clone(),
        git_commit: git_commit.clone(),
        container_image: repo_config.image.clone(),
        duration: build_duration,
        exit_status,
    };

    let log_file =
        match logs::save_build_log(log_dir, &meta, &build_stdout_file, &build_stderr_file).await {
            Ok(path) => path,
            Err(e) => {
                error!("[{site_name}] failed to save build log: {e}");
                let _ = tokio::fs::remove_file(&build_stdout_file).await;
                let _ = tokio::fs::remove_file(&build_stderr_file).await;
                // Non-fatal for log save — continue if build succeeded
                log_dir.join(site_name).join(format!("{timestamp}.log"))
            }
        };

    // If build failed, run hook (if configured) then return error
    if let Err(e) = build_result {
        error!("[{site_name}] build failed");
        run_hook_if_configured(
            site,
            site_name,
            &clone_dir,
            base_dir,
            log_dir,
            &site_log_dir,
            &timestamp,
            "failed",
            &env,
        )
        .await;
        update_final_state(
            base_dir,
            site_name,
            "failed",
            git_commit.as_deref().unwrap_or(""),
            start_time.elapsed(),
        )
        .await;
        return Err(e);
    }

    // 5. Publish assets (with same timestamp as log)
    info!(
        "[{site_name}] publishing assets: public={}",
        repo_config.public
    );
    let publish_result = publish::publish(
        base_dir,
        site_name,
        &clone_dir,
        &repo_config.public,
        &timestamp,
    )
    .await?;

    info!(
        "[{site_name}] deployment completed successfully: build_dir={} timestamp={}",
        publish_result.build_dir.display(),
        publish_result.timestamp
    );

    // 6. Run post-deploy hook (non-fatal)
    let mut final_status = "success";
    if let Some(hook_success) = run_hook_if_configured(
        site,
        site_name,
        &publish_result.build_dir,
        base_dir,
        log_dir,
        &site_log_dir,
        &timestamp,
        "success",
        &env,
    )
    .await
    {
        if hook_success {
            info!("[{site_name}] post-deploy hook completed");
        } else {
            warn!("[{site_name}] post-deploy hook failed (non-fatal)");
            final_status = "hook failed";
        }
    }

    // Write final state + set current build
    update_final_state(
        base_dir,
        site_name,
        final_status,
        git_commit.as_deref().unwrap_or(""),
        start_time.elapsed(),
    )
    .await;
    state::set_current(base_dir, site_name, &timestamp).await;

    // 7. Cleanup old builds (non-fatal if it fails)
    if let Err(e) =
        cleanup::cleanup_old_builds(base_dir, log_dir, site_name, max_builds_to_keep).await
    {
        warn!("[{site_name}] cleanup failed (non-fatal): {e}");
    }

    let duration = start_time.elapsed();
    Ok(PipelineResult {
        build_dir: publish_result.build_dir,
        log_file,
        timestamp,
        duration,
    })
}

/// Run the post-deploy hook if configured. Returns `Some(success)` if the hook
/// ran, or `None` if no hook is configured.
#[allow(clippy::too_many_arguments)]
async fn run_hook_if_configured(
    site: &SiteConfig,
    site_name: &str,
    build_dir: &Path,
    base_dir: &Path,
    log_dir: &Path,
    site_log_dir: &Path,
    timestamp: &str,
    build_status: &str,
    env: &HashMap<String, String>,
) -> Option<bool> {
    let hook_cmd = site.post_deploy.as_ref()?;
    info!("[{site_name}] running post-deploy hook (build_status={build_status})");

    let hook_stdout_tmp = site_log_dir.join(format!("{timestamp}-hook-stdout.tmp"));
    let hook_stderr_tmp = site_log_dir.join(format!("{timestamp}-hook-stderr.tmp"));
    let public_dir = base_dir.join("builds").join(site_name).join("current");

    let hook_result = Box::pin(hook::run_post_deploy_hook(
        hook_cmd,
        site_name,
        build_dir,
        &public_dir,
        timestamp,
        build_status,
        env,
        &hook_stdout_tmp,
        &hook_stderr_tmp,
    ))
    .await;

    if let Err(e) = logs::save_hook_log(log_dir, site_name, timestamp, &hook_result).await {
        error!("[{site_name}] failed to save hook log: {e}");
        let _ = tokio::fs::remove_file(&hook_stdout_tmp).await;
        let _ = tokio::fs::remove_file(&hook_stderr_tmp).await;
    }

    Some(hook_result.success)
}

/// Update the latest build entry with final status, commit, and duration. Best-effort.
async fn update_final_state(
    base_dir: &Path,
    site_name: &str,
    status: &str,
    git_commit: &str,
    duration: Duration,
) {
    let s = status.to_owned();
    let c = git_commit.to_owned();
    let d = logs::format_duration(duration);
    state::update_latest_build(base_dir, site_name, |e| {
        e.status = s;
        e.git_commit = c;
        e.duration = d;
    })
    .await;
}

/// Save a build log for errors that occur before the build starts.
async fn save_build_log_for_error(
    log_dir: &Path,
    site_name: &str,
    timestamp: &str,
    start_time: Instant,
    git_commit: Option<String>,
    phase: &str,
    error_msg: &str,
) {
    let meta = BuildLogMeta {
        site_name: site_name.to_owned(),
        timestamp: timestamp.to_owned(),
        git_commit,
        container_image: format!("(failed at {phase})"),
        duration: start_time.elapsed(),
        exit_status: BuildExitStatus::Failed {
            exit_code: None,
            error: error_msg.to_owned(),
        },
    };

    let site_log_dir = log_dir.join(site_name);
    let _ = tokio::fs::create_dir_all(&site_log_dir).await;
    let stdout_tmp = site_log_dir.join(format!("{timestamp}-stdout.tmp"));
    let stderr_tmp = site_log_dir.join(format!("{timestamp}-stderr.tmp"));
    let _ = tokio::fs::File::create(&stdout_tmp).await;
    let _ = tokio::fs::File::create(&stderr_tmp).await;

    if let Err(e) = logs::save_build_log(log_dir, &meta, &stdout_tmp, &stderr_tmp).await {
        error!("[{site_name}] failed to save build log: {e}");
        let _ = tokio::fs::remove_file(&stdout_tmp).await;
        let _ = tokio::fs::remove_file(&stderr_tmp).await;
    }
}