use crate::db::models::IssueDetail;

pub fn generate_rca_markdown(detail: &IssueDetail) -> String {
    let issue = &detail.issue;

    let mut md = String::new();

    md.push_str(&format!("# Root Cause Analysis: {}\n\n", issue.title));

    md.push_str("## Issue Summary\n\n");
    md.push_str("| Field | Value |\n");
    md.push_str("|-------|-------|\n");
    md.push_str(&format!("| **Issue ID** | {} |\n", issue.id));
    md.push_str(&format!("| **Category** | {} |\n", issue.category));
    md.push_str(&format!("| **Status** | {} |\n", issue.status));
    md.push_str(&format!("| **Severity** | {} |\n", issue.severity));
    md.push_str(&format!("| **Source** | {} |\n", issue.source));
    md.push_str(&format!(
        "| **Assigned To** | {} |\n",
        if issue.assigned_to.is_empty() {
            "Unassigned"
        } else {
            &issue.assigned_to
        }
    ));
    md.push_str(&format!("| **Created** | {} |\n", issue.created_at));
    md.push_str(&format!("| **Last Updated** | {} |\n", issue.updated_at));
    if let Some(ref resolved) = issue.resolved_at {
        md.push_str(&format!("| **Resolved** | {} |\n", resolved));
    }
    md.push_str("\n");

    if !issue.description.is_empty() {
        md.push_str("## Description\n\n");
        md.push_str(&issue.description);
        md.push_str("\n\n");
    }

    // 5 Whys Analysis
    md.push_str("## 5 Whys Analysis\n\n");
    if detail.resolution_steps.is_empty() {
        md.push_str("_No 5-whys analysis has been performed yet._\n\n");
    } else {
        for step in &detail.resolution_steps {
            md.push_str(&format!(
                "### Why #{}: {}\n\n",
                step.step_order, step.why_question
            ));
            if !step.answer.is_empty() {
                md.push_str(&format!("**Answer:** {}\n\n", step.answer));
            } else {
                md.push_str("_Awaiting answer._\n\n");
            }
            if !step.evidence.is_empty() {
                md.push_str(&format!("**Evidence:** {}\n\n", step.evidence));
            }
        }
    }

    // Root Cause
    md.push_str("## Root Cause\n\n");
    if let Some(last_step) = detail.resolution_steps.last() {
        if !last_step.answer.is_empty() {
            md.push_str(&format!(
                "Based on the 5-whys analysis, the root cause is:\n\n> {}\n\n",
                last_step.answer
            ));
        } else {
            md.push_str(
                "_The 5-whys analysis is incomplete. Complete it to identify the root cause._\n\n",
            );
        }
    } else {
        md.push_str("_Perform the 5-whys analysis to identify the root cause._\n\n");
    }

    // Log Files
    md.push_str("## Log Files Analyzed\n\n");
    if detail.log_files.is_empty() {
        md.push_str("_No log files attached._\n\n");
    } else {
        md.push_str("| File | Size | Redacted | Hash |\n");
        md.push_str("|------|------|----------|------|\n");
        for lf in &detail.log_files {
            md.push_str(&format!(
                "| {} | {} bytes | {} | {}... |\n",
                lf.file_name,
                lf.file_size,
                if lf.redacted { "Yes" } else { "No" },
                &lf.content_hash[..8.min(lf.content_hash.len())],
            ));
        }
        md.push_str("\n");
    }

    // Corrective Actions
    md.push_str("## Corrective Actions\n\n");
    md.push_str("### Immediate Actions\n\n");
    md.push_str("- [ ] _Document immediate mitigations taken_\n\n");
    md.push_str("### Long-Term Actions\n\n");
    md.push_str("- [ ] _Document preventive measures_\n");
    md.push_str("- [ ] _Document monitoring improvements_\n\n");

    // Lessons Learned
    md.push_str("## Lessons Learned\n\n");
    md.push_str("- _What went well during the response?_\n");
    md.push_str("- _What could be improved?_\n");
    md.push_str("- _What processes need updating?_\n\n");

    md.push_str("---\n\n");
    md.push_str(&format!(
        "_Generated by TFTSR IT Triage on {}_\n",
        chrono::Utc::now().format("%Y-%m-%d %H:%M UTC")
    ));

    md
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::db::models::{Issue, IssueDetail, LogFile, ResolutionStep};

    fn make_test_detail() -> IssueDetail {
        IssueDetail {
            issue: Issue {
                id: "test-123".to_string(),
                title: "Database connection timeout".to_string(),
                description: "Users report 500 errors on login.".to_string(),
                severity: "high".to_string(),
                status: "investigating".to_string(),
                category: "database".to_string(),
                source: "manual".to_string(),
                created_at: "2025-01-15 10:00:00".to_string(),
                updated_at: "2025-01-15 12:00:00".to_string(),
                resolved_at: None,
                assigned_to: "oncall-eng".to_string(),
                tags: "[]".to_string(),
            },
            log_files: vec![LogFile {
                id: "lf-1".to_string(),
                issue_id: "test-123".to_string(),
                file_name: "app.log".to_string(),
                file_path: "/tmp/app.log".to_string(),
                file_size: 2048,
                mime_type: "text/plain".to_string(),
                content_hash: "abc123def456".to_string(),
                uploaded_at: "2025-01-15 10:30:00".to_string(),
                redacted: false,
            }],
            resolution_steps: vec![
                ResolutionStep {
                    id: "rs-1".to_string(),
                    issue_id: "test-123".to_string(),
                    step_order: 1,
                    why_question: "Why are users getting 500 errors?".to_string(),
                    answer: "The database connection pool is exhausted.".to_string(),
                    evidence: "Connection pool metrics show 100/100 used.".to_string(),
                    created_at: "2025-01-15 11:00:00".to_string(),
                },
                ResolutionStep {
                    id: "rs-2".to_string(),
                    issue_id: "test-123".to_string(),
                    step_order: 2,
                    why_question: "Why is the connection pool exhausted?".to_string(),
                    answer: "Queries are not being released after completion.".to_string(),
                    evidence: "".to_string(),
                    created_at: "2025-01-15 11:15:00".to_string(),
                },
            ],
            conversations: vec![],
        }
    }

    #[test]
    fn test_rca_contains_title() {
        let md = generate_rca_markdown(&make_test_detail());
        assert!(md.contains("# Root Cause Analysis: Database connection timeout"));
    }

    #[test]
    fn test_rca_contains_issue_summary_table() {
        let md = generate_rca_markdown(&make_test_detail());
        assert!(md.contains("| **Issue ID** | test-123 |"));
        assert!(md.contains("| **Severity** | high |"));
        assert!(md.contains("| **Assigned To** | oncall-eng |"));
    }

    #[test]
    fn test_rca_contains_five_whys() {
        let md = generate_rca_markdown(&make_test_detail());
        assert!(md.contains("### Why #1: Why are users getting 500 errors?"));
        assert!(md.contains("**Answer:** The database connection pool is exhausted."));
        assert!(md.contains("**Evidence:** Connection pool metrics"));
    }

    #[test]
    fn test_rca_contains_root_cause() {
        let md = generate_rca_markdown(&make_test_detail());
        assert!(md.contains("Queries are not being released after completion."));
    }

    #[test]
    fn test_rca_contains_log_files() {
        let md = generate_rca_markdown(&make_test_detail());
        assert!(md.contains("app.log"));
        assert!(md.contains("2048 bytes"));
    }

    #[test]
    fn test_rca_empty_steps_shows_placeholder() {
        let mut detail = make_test_detail();
        detail.resolution_steps.clear();
        let md = generate_rca_markdown(&detail);
        assert!(md.contains("No 5-whys analysis has been performed yet."));
    }

    #[test]
    fn test_rca_unassigned_shows_unassigned() {
        let mut detail = make_test_detail();
        detail.issue.assigned_to = String::new();
        let md = generate_rca_markdown(&detail);
        assert!(md.contains("Unassigned"));
    }
}