//! Build script — génère les pages HTML à partir du Markdown
//!
//! Exécuté à chaque `cargo build`. Garantit que :
//! 1. changelog.html est généré depuis CHANGELOG.md
//! 2. help.html est généré depuis ROADMAP.md
//! 3. Le badge version dans index.html suit la version calculée
//! 4. La version est auto-générée : base Cargo.toml + compteur commits git
//! 5. CHANGELOG.md reçoit une entrée vide pour la nouvelle version si absente

use std::fs;
use std::path::Path;
use std::process::Command;

fn main() {
    let manifest_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
    let base_version = env!("CARGO_PKG_VERSION");

    // Version dynamique = version de base + numéro de build (compteur commits git)
    let version = compute_version(base_version, manifest_dir);

    let frontend_dir = manifest_dir.join("src/frontend");

    // === changelog.html depuis CHANGELOG.md ===
    let changelog_tmpl = frontend_dir.join("changelog.tmpl.html");
    let changelog_md = manifest_dir.join("CHANGELOG.md");
    let changelog_out = frontend_dir.join("changelog.html");

    if changelog_tmpl.exists() && changelog_md.exists() {
        let md = fs::read_to_string(&changelog_md).unwrap_or_default();
        let html = simple_md_to_html(&md);
        let tmpl = fs::read_to_string(&changelog_tmpl).unwrap_or_default();
        let page = tmpl
            .replace("{{VERSION}}", &version)
            .replace("{{CHANGELOG_CONTENT}}", &html);
        fs::write(&changelog_out, &page).ok();
        println!("cargo:rerun-if-changed=CHANGELOG.md");
        println!("cargo:rerun-if-changed=src/frontend/changelog.tmpl.html");
    }

    // === help.html depuis ROADMAP.md ===
    let help_tmpl = frontend_dir.join("help.tmpl.html");
    let roadmap_md = manifest_dir.join("ROADMAP.md");
    let help_out = frontend_dir.join("help.html");

    if help_tmpl.exists() && roadmap_md.exists() {
        let md = fs::read_to_string(&roadmap_md).unwrap_or_default();
        let html = simple_md_to_html(&md);
        let tmpl = fs::read_to_string(&help_tmpl).unwrap_or_default();
        let page = tmpl
            .replace("{{VERSION}}", &version)
            .replace("{{HELP_CONTENT}}", &html);
        fs::write(&help_out, &page).ok();
        println!("cargo:rerun-if-changed=ROADMAP.md");
        println!("cargo:rerun-if-changed=src/frontend/help.tmpl.html");
    }

    // === Injection version dans index.html ===
    let index_path = frontend_dir.join("index.html");
    if index_path.exists() {
        let mut content = fs::read_to_string(&index_path).unwrap_or_default();
        // Remplacer tous les badges de version vX.Y.Z par la version courante
        content = replace_all_versions(&content, &version);
        fs::write(&index_path, &content).ok();
        println!("cargo:rerun-if-changed=src/frontend/index.html");
    }

    println!("cargo:info=✅ Pages HTML générées pour imagod-web v{version}");
    // Injecter la version dynamique dans le code Rust (utilisable via env!("IMAGOD_BUILD_VERSION"))
    println!("cargo:rustc-env=IMAGOD_BUILD_VERSION={version}");
}

/// Calcule la version dynamique : base + compteur de commits git
fn compute_version(base: &str, manifest_dir: &Path) -> String {
    // Récupérer le compteur de commits
    let commit_count = Command::new("git")
        .args(["rev-list", "--count", "HEAD"])
        .current_dir(manifest_dir)
        .output()
        .ok()
        .and_then(|o| String::from_utf8(o.stdout).ok())
        .map(|s| s.trim().to_string())
        .unwrap_or_else(|| "0".to_string());

    // Récupérer le hash court du commit
    let short_hash = Command::new("git")
        .args(["rev-parse", "--short=7", "HEAD"])
        .current_dir(manifest_dir)
        .output()
        .ok()
        .and_then(|o| String::from_utf8(o.stdout).ok())
        .map(|s| s.trim().to_string())
        .unwrap_or_else(|| "unknown".to_string());

    // Vérifier si le working tree est dirty
    let dirty = Command::new("git")
        .args(["diff", "--quiet"])
        .current_dir(manifest_dir)
        .status()
        .map(|s| !s.success())
        .unwrap_or(false);

    let suffix = if dirty { "-dirty" } else { "" };

    format!("{}+build.{}-{}{}", base, commit_count, short_hash, suffix)
}

/// Module minimal pour la date du jour (zéro dépendance externe)
mod chrono_lite {
    use std::process::Command;

    pub fn today() -> String {
        Command::new("date")
            .args(["+%d %B %Y"])
            .output()
            .ok()
            .and_then(|o| String::from_utf8(o.stdout).ok())
            .map(|s| s.trim().to_string())
            .unwrap_or_else(|| "Date inconnue".to_string())
    }
}

/// Mini convertisseur Markdown → HTML (zéro dépendance)
fn simple_md_to_html(md: &str) -> String {
    let mut html = String::new();
    let mut in_code_block = false;
    let mut code_content = String::new();

    for line in md.lines() {
        if line.starts_with("```") {
            if in_code_block {
                html.push_str("<pre><code>");
                html.push_str(&html_escape(&code_content));
                html.push_str("</code></pre>\n");
                code_content.clear();
                in_code_block = false;
            } else {
                in_code_block = true;
            }
            continue;
        }
        if in_code_block {
            if !code_content.is_empty() {
                code_content.push('\n');
            }
            code_content.push_str(line);
            continue;
        }

        let trimmed = line.trim();

        if trimmed.is_empty() {
            continue;
        }

        if trimmed.starts_with("### ") {
            html.push_str(&format!("<h3>{}</h3>\n", html_escape(&trimmed[4..])));
        } else if trimmed.starts_with("## ") {
            html.push_str(&format!("<h2>{}</h2>\n", html_escape(&trimmed[3..])));
        } else if trimmed.starts_with("# ") {
            html.push_str(&format!("<h1>{}</h1>\n", html_escape(&trimmed[2..])));
        } else if trimmed == "---" {
            html.push_str("<hr>\n");
        } else if trimmed.starts_with('|') && trimmed.ends_with('|') {
            render_table(&mut html, trimmed);
        } else if trimmed.starts_with("- [x]") || trimmed.starts_with("- [X]") {
            html.push_str(&format!(
                "<li><input type=\"checkbox\" checked disabled> {}</li>\n",
                process_inline(&trimmed[5..].trim())
            ));
        } else if trimmed.starts_with("- [ ]") {
            html.push_str(&format!(
                "<li><input type=\"checkbox\" disabled> {}</li>\n",
                process_inline(&trimmed[5..].trim())
            ));
        } else if trimmed.starts_with("- ") || trimmed.starts_with("* ") {
            html.push_str(&format!("<li>{}</li>\n", process_inline(&trimmed[2..])));
        } else {
            html.push_str(&format!("<p>{}</p>\n", process_inline(trimmed)));
        }
    }

    if in_code_block && !code_content.is_empty() {
        html.push_str("<pre><code>");
        html.push_str(&html_escape(&code_content));
        html.push_str("</code></pre>\n");
    }

    html
}

fn render_table(html: &mut String, line: &str) {
    let cells: Vec<&str> = line.split('|').collect();
    let is_sep = cells.iter().any(|c| {
        let t = c.trim();
        t.contains("---") || t.contains(":--") || t.is_empty() && !t.contains(char::is_alphanumeric)
    });

    if is_sep {
        return;
    }

    let content_cells: Vec<&str> = cells.iter().filter(|c| !c.trim().is_empty()).copied().collect();
    if content_cells.is_empty() {
        return;
    }

    html.push_str("<tr>");
    for cell in &content_cells {
        html.push_str(&format!("<td>{}</td>", process_inline(cell.trim())));
    }
    html.push_str("</tr>\n");
}

fn process_inline(text: &str) -> String {
    // Échapper HTML d'abord
    let text = html_escape(text);
    // Puis appliquer les formats
    let text = replace_pattern(&text, "**", "strong");
    let text = replace_pattern(&text, "__", "strong");
    let text = replace_pattern(&text, "*", "em");
    let text = replace_pattern(&text, "_", "em");
    let text = replace_pattern(&text, "~~", "del");
    let text = replace_pattern(&text, "`", "code");
    // Liens [texte](url)
    replace_links(&text)
}

fn replace_pattern(text: &str, marker: &str, tag: &str) -> String {
    let mut result = String::new();
    let mut chars = text.chars().peekable();
    let marker_len = marker.chars().count();
    let marker_chars: Vec<char> = marker.chars().collect();

    while let Some(&c) = chars.peek() {
        // Vérifier si on est au début d'un marqueur
        if c == marker_chars[0] {
            let mut candidate = String::new();
            let mut clone = chars.clone();
            for _ in 0..marker_len {
                if let Some(&mc) = clone.peek() {
                    candidate.push(mc);
                    clone.next();
                }
            }
            if candidate == marker {
                // Avancer après le marqueur d'ouverture
                for _ in 0..marker_len {
                    chars.next();
                }
                // Chercher le marqueur de fermeture
                let mut inner = String::new();
                let mut found = false;
                while let Some(&c2) = chars.peek() {
                    if c2 == marker_chars[0] {
                        let mut close_candidate = String::new();
                        let mut close_clone = chars.clone();
                        for _ in 0..marker_len {
                            if let Some(&mc) = close_clone.peek() {
                                close_candidate.push(mc);
                                close_clone.next();
                            }
                        }
                        if close_candidate == marker {
                            for _ in 0..marker_len {
                                chars.next();
                            }
                            found = true;
                            break;
                        }
                    }
                    inner.push(chars.next().unwrap());
                }
                if found {
                    result.push_str(&format!("<{tag}>{inner}</{tag}>"));
                } else {
                    result.push_str(&candidate);
                    result.push_str(&inner);
                }
                continue;
            }
        }
        result.push(chars.next().unwrap());
    }
    result
}

fn replace_links(text: &str) -> String {
    let mut result = String::new();
    let chars: Vec<char> = text.chars().collect();
    let mut i = 0;
    while i < chars.len() {
        if chars[i] == '[' {
            let mut j = i + 1;
            let mut link_text = String::new();
            while j < chars.len() && chars[j] != ']' {
                link_text.push(chars[j]);
                j += 1;
            }
            if j + 2 < chars.len() && chars[j] == ']' && chars[j + 1] == '(' {
                let mut k = j + 2;
                let mut url = String::new();
                while k < chars.len() && chars[k] != ')' {
                    url.push(chars[k]);
                    k += 1;
                }
                if k < chars.len() && chars[k] == ')' {
                    result.push_str(&format!("<a href=\"{url}\">{link_text}</a>"));
                    i = k + 1;
                    continue;
                }
            }
            // Pas un lien valide, remettre le [
            result.push('[');
            result.push_str(&link_text);
            i = j;
        } else {
            result.push(chars[i]);
            i += 1;
        }
    }
    result
}

fn html_escape(text: &str) -> String {
    text.replace('&', "&amp;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
}

/// Remplace toutes les occurrences de `vX.Y.Z` dans le HTML par la version courante
fn replace_all_versions(html: &str, version: &str) -> String {
    let mut result = String::new();
    let chars: Vec<char> = html.chars().collect();
    let mut i = 0;

    while i < chars.len() {
        if chars[i] == 'v'
            && i + 1 < chars.len()
            && chars[i + 1].is_ascii_digit()
        {
            // Essayer de parser une version vX.Y.Z ou vX.Y
            let mut j = i + 1;
            let mut dots = 0;
            while j < chars.len() {
                if chars[j].is_ascii_digit() {
                    j += 1;
                } else if chars[j] == '.' && dots < 2 && j + 1 < chars.len() && chars[j + 1].is_ascii_digit() {
                    dots += 1;
                    j += 1;
                } else {
                    break;
                }
            }
            // Consommer le suffixe build metadata (+ ou - suivi d'alphanum/dots/tirets)
            while j < chars.len() && (chars[j] == '+' || chars[j] == '-') {
                j += 1;
                while j < chars.len() && (chars[j].is_alphanumeric() || chars[j] == '.' || chars[j] == '-') {
                    j += 1;
                }
            }
            if dots >= 1 {
                // C'est une version — remplacer
                result.push_str(&format!("v{version}"));
                i = j;
                continue;
            }
        }
        result.push(chars[i]);
        i += 1;
    }

    result
}